technical assistance consultant’s report · 2020-02-26 · technical assistance consultant’s...

Technical Assistance Consultant’s Report

Project Number: 49019-001December 2017

People's Republic of China: Sustainable Management of Fly Ash from Municipal Solid Waste Incineration

Prepared by the China Urban Construction Design & Research Co., Ltd. Beijing, the People's Republic of China

For the Tianjin Municipal Government

This consultant’s report does not necessarily reflect the views of ADB or the Government concerned, and ADB and the Government cannot be held liable for its contents. For project preparatory technical

assistance: All the views expressed herein may not be incorporated into the proposed project’s design.

CURRENCY EQUIVALENTS (as of 20 December 2017)

Currency Unit CNY1.00

$1.00

– yuan (CNY)= $ 0.1514= CNY6.6036

ABBREVIATIONS

ADBAPCBABFBS ENCENCFRDOCDTECEIAEPEPAEUEWCFAFTGBGHGHMAHRGC/HRMS

HxCDDsJISMDLMSWMSWIPNDNRAODPRCUNEPUSA

– Asian Development Bank– Air Pollution Control– Bottom Ash– Bag Filter– British Standard European Norm– European Committee for Standardization– Code of Federal Regulations– Dissolved Organic Carbon– Deformation Temperature– European Commission– Enzyme Immuno Assay– Environmental Protection– Environmental Protection Agency– European Union– European Waste Catalogue– Fly Ash– Flow Temperature– Guo Biao (Chinese National Standard)– Greenhouse Gas– Hot-Mix Asphalt– High-Resolution Gas Chromatography Combined

with High-Resolution Mass Spectrometry– Hexachlorodibenzodioxins– Japanese Industrial Standard– Laboratory Detection Limit– Municipal Solid Waste– Municipal Solid Waste Incineration Plant– No detection– National Rivers Association– Absorbance Values– People's Republic of China– United National Environment Programme– United States of America

RCRARDFSTTATCLPTDSWACXPS

– Resource Conservation and Recovery Act– Refuse Derived Fuel– Softening Temperature– Technical Assistance– Toxicity Characteristic Leaching Procedure– Total Dissolved Solids– Waste Acceptance Criteria– X-ray photoelectron spectroscopy

NOTE

In this report, "$" refers to United States dollars.

Asian Development Bank

TA-8963 PRC: Sustainable Management of Fly Ash from Municipal Solid Waste Incineration (49019-001)

Final Report

China Urban Construction Design & Research Institute Co., Ltd.

Dec 20, 2017

TA-8963 PRC Final Report Contents

I

CONTENTS

ABBREVIATIONS......................................................................................................... vi List of Figures ......................................................................................................... viiiList of Tables ............................................................................................................ xCHAPTER1 PROJECT INTRODUCTION .................................................................... 1

1.1 TA Background .......................................................................................................................

1.2 TA Objective ............................................................................................................................

1.3 TA Scope and Activities........................................................................................................

1.4 TA Deliverables ......................................................................................................................

CHAPTER2 STATUS OF MUNICIPAL SOLID WASTE MANAGEMENT AND CHARACTERISTICS OF FLY ASH IN PRC ................................................................. 4

2.1 Municipal Solid Waste Management Status and Development Process in China

2.1.1 Sources and Generation of Municipal Solid Waste ...........................................

2.1.2 Components and Physicochemical Properties of MSW ..................................

2.1.3 Characteristics of Rural Solid Waste in China ....................................................

2.1.4 Comparative Analysis on Characteristics of Solid Waste between China and Abroad ..................................................................................................................................

2.1.5 Treatment and Disposal of MSW .........................................................................

2.2 Generation and Characteristics of MSWI Fly Ash .......................................................

2.2.1 Physical and Chemical Characteristics of MSWI Bottom Ash ......................

2.2.2 Characteristics of Generation and Pollution of MSWI Fly Ash .....................

2.2.3 Basic Physicochemical Properties of MSWI Fly Ash ......................................

2.2.4 Heavy Metal Leaching ............................................................................................

2.2.5 Influence of Incinerator Type on Fly Ash Characteristics...............................

2.2.6 Fly Ash Properties of Diverse Flue Gas Treatment Techniques ...................

2.2.7 Effect of Combustion Conditions on Fly Ash Properties ................................

2.2.8 Impact Prediction of Waste Classification on Fly Ash.....................................

2.3 Environmental Impact of Fly Ash .....................................................................................

2.3.1 Pollution of Soluble Salts .......................................................................................

2.3.2 Pollution of Heavy Metals ......................................................................................

2.3.3 Pollution of Dioxins..................................................................................................

2.3.4 Environmental Impact and Control of Secondary Pollution Caused by Transportation Littering of Fly Ash .................................................................................

2.4 Summary ...............................................................................................................................

CHAPTER3 SURVEY AND ANALYSIS OF FLY ASH FROM TYPICAL INCINERATORS IN PRC............................................................................................. 46

3.1 Selection of Typical Incinerators ......................................................................................

3.2 Survey Content .................................................................................................................... 3.3 Sampling and Analysis of Fly Ash ...................................................................................

3.3.1 Fly Ash Sampling .....................................................................................................


II

3.3.2 Test Methods ............................................................................................................

3.4 Results and Analysis ..........................................................................................................

3.4.1 Fly Ash Sample Numbering ..................................................................................

3.4.2 Result Analysis .........................................................................................................

3.5 Summary ...............................................................................................................................

CHAPTER4 TECHNOLOGIES FOR REUSE, TREATMENT AND DISPOSAL OF MSW INCINERATION FLY ASH ................................................................................. 67

4.1 Fly Ash Treatment and Disposal Technologies and Reuse Methods ......................

4.1.1 Fly Ash Treatment and Disposal Technologies ................................................

4.1.2 Utilization and Utilization Methods of Fly Ash Resource................................

4.1.3 Fly Ash Pretreatment Technology before Treatment/Disposal ..................... 4.2 Environmental Impacts of Fly Ash Disposal Technologies ........................................

4.2.1 Fly Ash Disposal Technologies.............................................................................

4.2.2 Safe and Sustainable Utilization ..........................................................................

4.3 Cost-benefit Analysis of Typical Technologies..............................................................

4.3.1 Cost-benefit Analysis of Products........................................................................

4.3.2 Environmental Economic Benefits ......................................................................

4.4 Management Status of Municipal Solid Wastes Incineration Fly Ash in China ....

4.4.1 Application Status of MSW Incineration Fly Ash’s Safe Disposal Technology ................................................................................................................................................

4.4.2 The Development of and Problems Faced by the Treatment and Disposal of MSW Incineration Fly Ash in China ........................................................................

4.5 Summary .............................................................................................................................

CHAPTER5 EXISTING POLICIES AND REGULATIONS SYSTEM IN CHINA ...... 1165.1 Regulations on MSWI Fly Ash Management in PRC ...............................................

5.1.1 State Regulations ..................................................................................................

5.1.2 Local Regulations ..................................................................................................

5.2 Environment Supervision Systems and Management Organization Frames of MSW Incineration Fly Ash in China......................................................................................

5.2.1 Ministry of Environmental Protection ................................................................

5.2.2 Local Competent Administrative Departments of Environmental Protection ..............................................................................................................................................

5.3 Standards and Systems about MSW Incineration Fly Ash......................................

5.3.1 MSW Incineration Standards ..............................................................................

5.3.2 Standards for Disposal of MSW Incineration Fly Ash ...................................

5.3.3 Standards for Comprehensive Utilization of MSW Incineration Fly Ash ..

5.4. Summary ............................................................................................................................

CHAPTER6 ADVANCED INTERNATIONAL EXPERIENCE OF MSWI FLY ASH MANAGEMENT 157

6.1 Japan ....................................................................................................................................

6.1.1 MSW Incinerated and MSWIP Fly Ash Generation and Characteristics..

6.1.2 Mainstream Technologies and Application ......................................................

6.1.3 Policies, Laws, Regulations and Standards ....................................................


III

6.1.4 Experiences and Lessons ...................................................................................

6.2 Europe..................................................................................................................................





6.3 United States ......................................................................................................................





6.4 Summary .............................................................................................................................

CHAPTER7 CHALLENGES FOR SUSTAINABLE MANAGEMENT OF MSWI FLY ASH IN THE PRC ...................................................................................................... 235

7.1 Comparative Analysis of Gap between International and Domestic Technologies ......................................................................................................................................................

7.1.1 Japan ........................................................................................................................

7.1.2 USA...........................................................................................................................

7.1.3 EU .............................................................................................................................

7.1.4 China ........................................................................................................................

7.2 Technical Challenge ..........................................................................................................

7.2.1 Cement Solidification ............................................................................................

7.2.2 Chemical Stabilization ..........................................................................................

7.2.3 High Temperature Heat Treatment and Solidification Technology .............

7.2.4 Safe Landfill Disposal ........................................................................................... 7.3 Policies and Regulations Challenge .............................................................................

7.3.1 Problems in the Solid Waste Law ......................................................................

7.3.2 Unsound Standards, Norms ...............................................................................

7.4 Summary .............................................................................................................................

CHAPTER 8 ASSESSMENT OF TREATMENT/DISPOSAL TECHNOLOGIES FOR MSWI FLY ASH 248

8.1 Qualitative Evaluation of Different Treatment Options .............................................

8.2 Quantitative Comparison and Selection of Different Treatment Options .............

8.2.1 Volumetric Reduction Efficiency.........................................................................

8.2.2 Environmental Risks of Treatment / Disposal................................................. 8.2.3 Control Efficiency of Total Heavy Metal Leaching in Product .....................

8.2.4 The Economic Value of Resource Recovery ..................................................

8.3 Summary .............................................................................................................................

CHAPTER 9 TECHNICAL SUGGESTIONS ON THE SUSTAINABLE MANAGEMENT OF MSW INCINERATION FLY ASH IN CHINA ............................ 261

9.1 Fly Ash Management and Technology Selection Principles ...................................

9.2 Technology Suggestions Suitable for China’s Current Situation ...........................

9.2.1 Solidification and Stabilization – Sanitary Landfill .........................................


IV

9.2.2 Sintering Technology ............................................................................................

9.2.3 Cement Kiln Co-treatment ................................................................................... 9.2.4 High-temperature Melting ....................................................................................

9.2.5 Heavy Metal Recovery .........................................................................................

9.2.6 Colloidal Filling and Mining Collaborative Resource Utilization Technology ..............................................................................................................................................

9.2.7 Fly Ash Source Reduction Technology .............................................................

9.2.8 Pollutant Reduction Technology - Waste Classification Technology .........

9.3 Prediction on the Environmental Impact ...................................................................... 9.3.1 Mitigation Measures on Environmental Pollutions Caused by Poor Management ..................................................................................................................... 9.3.2 The Environmental Impact of MSWI Fly Ash Storage / Treatment and Disposal Process .............................................................................................................

9.3.3 MSW Incineration Fly Ash Products’ Environmental Influence ..................

9.4 Expectations on the Economic Benefits of the Optimal Practicable Technology’s Application..................................................................................................................................

9.4.1 Cost of Technical Application ..............................................................................

9.4.2 Analysis on Product Value and Market Demand............................................

CHAPTER 10 SUSTAINABLE MANAGEMENT STANDARD AND POLICY SUGGESTIONS OF MSWI FLY ASH IN CHINA ...................................................... 282

10.1 Standard Suggestions....................................................................................................

10.2 Technical and Environmental Standards System of MSW Incineration Fly Ash ......................................................................................................................................................

10.2.1 Standard Draft for MSW Incineration Fly Ash’s Vitrification......................

10.2.2 Technical Specifications for Wastes Incineration Fly Ash’s Safe Disposal and Technical Specifications for MSW Incineration Fly Ash’s Stability...............

10.3 Policy and Management Recommendations............................................................

10.3.1 Recent Policy Recommendations ...................................................................

10.3.2 Future Policy Recommendations ....................................................................

10.3.3 Management Framework Recommendations ..............................................

10.3.4 Recommendations for Regulatory System and Framework .....................

10.3.5 Implementation Plan and Safeguarding Measures .....................................

10.4 Conclusion ........................................................................................................................

CHAPTER11 DEVELOPMENT OF MSWIP DATABASE AND SERVICE PLATFORM........................................................................................................ 297

11.1 Network Platform Environment Both at Home and Abroad ...................................

11.2 Network Platform Foundation Information Description ..........................................

11.2.1 Project Implementation Progress Statement ................................................

11.2.2 Functional Requirements Project Implementation ......................................

11.2.3 Project Implementation Basic Safety Instructions .......................................

11.3 Instructions of Network Platform Front Shows .........................................................

11.3.1 Instructions of Network Platform Front Designs ..........................................

11.3.2 Web Platform Front Page Description ............................................................

11.4 Project Facilities Management Platform ....................................................................


V

11.4.1 Network Platform Background Basic Information Description..................

11.4.2 Network Platform Background Instructions ...................................................

11.4.3 Home Page Navigation Management ............................................................

11.5 Test Report ........................................................................................................................ 11.6 Summary ...........................................................................................................................

CHAPTER12 CONCLUSIONS AND RECOMMENDATIONS .................................. 30812.1 Conclusions ......................................................................................................................

12.2 Recommendations ..........................................................................................................

12.2.1 Strengthening whole-process supervision ....................................................

12.2.2 Enhancing Capability of Utilization and Disposal ........................................ 12.2.3 Raising the Level of Utilization and Disposal ............................................... 12.2.4 Strengthening Source Reduction ....................................................................

References ........................................................................................................ 315Appendices ........................................................................................................ 321

Appendix 1 Summary of Workshops ...................................................................................

Appendix 2 Summary of Surveys .........................................................................................

Appendix 3 Summary of International Study Tour ............................................................

Appendix 4 Draft Technical Specification and Policy for Municipal Solid Waste Incineration Fly Ash..................................................................................................................

Appendix 5 The Engineering Manager System of Waste Processing Plant and Personnel Training in Japan ..................................................................................................

TA-8963 PRC Final Report Abbreviations

vi

ABBREVIATIONS

ADB Asian Development Bank

APC Air Pollution Control

BA Bottom Ash

BF Bag Filter

BS EN British Standard European Norm

CEN European Committee for Standardization

CFR Code of Federal Regulations

DOC Dissolved Organic Carbon

DT Deformation Temperature

EC European Commission

EIA Enzyme Immuno Assay

EP Environmental Protection

EPA Environmental Protection Agency

EU European Union

EWC European Waste Catalogue

FA Fly Ash

FT Flow Temperature

GB Guo Biao (Chinese National Standard)

GHG Greenhouse Gas

HMA Hot-Mix Asphalt

HRGC/HRMS High-Resolution Gas Chromatography Combined with High-

Resolution Mass Spectrometry

HxCDDs Hexachlorodibenzodioxins

JIS Japanese Industrial Standard

MDL Laboratory Detection Limit

MSW Municipal Solid Waste

MSWIP Municipal Solid Waste Incineration Plant

ND No detection

NRA National Rivers Association

OD Absorbance Values

TA-8963 PRC Final Report Abbreviations

vii

PRC People’s Republic of China

UNEP United National Environment Programme

USA United States of America

RCRA Resource Conservation and Recovery Act

RDF Refuse Derived Fuel

ST Softening Temperature

TA Technical Assistance

TCLP Toxicity Characteristic Leaching Procedure

TDS Total Dissolved Solids

WAC Waste Acceptance Criteria

XPS X-ray photoelectron spectroscopy

TA-8963 PRC Final Report List of Tables

viii

List of Figures

Figure 2-1 MSW Collection Amount in China Increases in Terms of Time

Figure 2-2 China's Rural Domestic Waste Components: (a)The Main Types of Rural

Domestic Waste; (b) Rural Domestic Waste Components

Figure 2-3 Guangzhou Likeng Waste Incineration Plant

Figure 2-4 Shanghai Laogang Wastes Incineration Power Plant

Figure 2-5 Number of MSW Treatment Facilities in PRC

Figure 2-6 Treatment Capacity of Different MSW Treatment Facilities

Figure 2-7 Treatment Capacity of Different Treatment Methods in China (2015)

Figure 2-8 Dry/Semi-dry Fly Ash Treatment and Purification Technique

Figure 2-9 Fly Ash Production Amount from 2010 to 2015

Figure 2-10 Fly Ash Photo

Figure 2-11 Size Distribution of Fly Ash

Figure2-12 Chemical Combining Morphology of Heavy Metals in Incineration Fly Ash

Figure 2-13 XRD Pattern of Fly Ash

Figure 2-14 The Main Composition Distribution of Different Types of Fly Ash: (a) Main

Components Distribution of Grate Boiler Fly Ash; (b) Main Components

Distribution of Fluidized Bed Fly Ash

Figure 2-15 Cl Content of Grate Boiler/Fluidized Bed Fly Ash

Figure 2-16 SO3 Content of Grate Boiler/Fluidized Bed Fly Ash

Figure 2-17 K2O Content of Grate Boiler /Fluidized Bed Fly Ash

Figure 2-16 Na2O Content of Grate Boiler /Fluidized Bed Fly Ash


Figure 3-1 Total Content of Heavy Metals in Incineration Fly Ash from Mechanical Grate

Furnace In Different Areas

Figure 3-2 Dioxin Toxic Equivalent in Incineration Fly Ash from the Same Type of

Incinerators in Different Areas


Boilers and Fluidized Beds in Tianjin Area


Boilers and Fluidized Beds in Jiangsu Area



ix

Boilers and Fluidized Beds in Zhejiang Area

Figure 3-6 Dioxin Toxic Equivalent in Incineration Fly Ash from Mechanical Grate Boiler

and Fluidized Bed in the Same Area

Figure 3-7 Impact of Different Flue Gas Treatment Processes on Total Content of

Heavy Metals in Fly Ash


Heavy Metals and Dioxin Toxic Equivalent in Fly Ash

Figure 3-9 3,2,3,7,8-TCDD Toxicity Response Value (pg • tube-1)

Figure 3-10 PCDD/F Toxicity Response Value (pg • tube-1)

Figure4-1 Cement Plant Fly Ash Pretreatment and Cement Kiln Co-processing

Figure4-2 Microwave Detoxification Demonstration Project Process Chart

Figure 4-3 Dioxins Low Temperature Pyrolysis Process Flow Chart



Figure 4-6 Shenzhen Laohukeng Wastes Incineration Plant

Figure 4-7 Beijing Liulihe Cement Co., Ltd.

Figure 4-8 Sintering Fly Ash Sintering Process Flow Chart

Figure 4-9 Tianjin Yiming Environmental Technology Co., Ltd.

Figure 4-10 Shanghai Plasma Co-disposal Flow Chart

Figure 4-11 Relation Between Fly Ash Generation Amount and Hazardous Wastes

Landfill Capacity Process Flow Chart of Beijing Liulihe

Figure 4-12 Relation Between Fly Ash Generation Amount and MSW Landfill Capacity

Figure 4-13 Beijing Building Materials Group

Figure 6-1 BF + Wet-type System

Figure 6-2 Dry-type + BF System

Figure 6-3 Ash and Residues Generated during MSW Incineration

Figure 6-4 Classification of ash treatment technologies

Figure 6-5 Differential Thermal Analysis

Figure 6-6 Treatment and Recycling Flow of Waste Incineration Ash

Figure 6-7 A Thermal Dechlorination Device for Fly Ash

Figure 6-8 Treatment Flow of Chubu Recycle Co., Ltd

Figure 6-9 Annual Average of Material Balance in Resource Recovery of Chubu

Figure 6-10 Concept Diagram of Eco-Cement Manufacturing

Figure 6-11 Eco-Cement System Flow


x

Figure 6-12 Tama Area Waste to Eco-Cement Plant

Figure 6-13 Processing Flow of Non-ferrous Recovery at Smelter

Figure 6-14 Control Flow of Fly Ash (Soot and Dust)

Figure 6-15 Dioxins Control Standards for Fly Ash Landfilling and Final Disposal Site

Figure 6-16 Treatment of Municipal Waste in European Countries in 2014

Figure 6-17 MSW Generation Rates, 1960 to 2014

Figure 6-18 Management of MSW in the United States, 2014

Figure 8-1 Different Disposal Technologies on the Fly Ash Volume Reduction Effect

Figure 8-2 Environmental Risk Sources for the Co-processing of Fly Ash and Cement

Kilns

Figure 8-3 Effect of Different Fly Ash Disposal Technologies on Total Heavy Metal

Leaching Products

Figure 10-1 Flowchart of the Substances and Energy Circulation

Figure 10-2 Comparison of Average Heavy Metal Content in Fly Ash from China and

Japan

Figure 10-3 Cost Structure for Fly Ash Disposal in Japan

List of Tables

Table 2-1 Physical Components of MSW in Major Cities of PRC and Abroad

Table 2-2 Content of Common MSW Compositions

Table 2-3 pH, Moisture Content, Value Heat and Ash Content of Common MSW

Table 2-4 Contrast of Domestic Waste between Rural Area and City

Table2-5 Domestic Waste Component Comparison at Home and Abroad

Table 2-6 Comparison of Three Waste Treatment Methods

Table 2-7 Melting Point and Boiling Point of Several Heavy Metal and Their

Compounds(℃)

Table 2-8 The Physical Composition of MSWI Bottom Ash from Somewhere

Table2-9 Melting Temperature Test Result of Fly Ash (℃)

Table 2-10 Chemical Compositions of Fly Ash(%)

Table 2-11 Heavy Metal Content of Fly Ash(mg/kg)

Table 2-12 Chemical Components of Fly Ash from Different Plants in Different Period

Table 2-13 Impact of Waste Classification on Heavy Metal Content in Fly Ash/Bottom

Ash mg/kg


xi

Table 3-1 Selected Incineration Plants For Fly Ash Sampling Survey

Table 3-2 Analysis Results of Total Content of Heavy Metals and Dioxin Equivalent in

Fly Ash Samples from Typical Incineration Plants

Table 3-3 Municipal Solid Waste Components in the Northern Typical Area

Table 3-4 Heavy Metal Content and Dioxin Toxicity Equivalent of Incineration Fly Ash

in the Northern Typical Area

Table 3-5 Municipal Solid Waste Components in the Eastern Typical Area


in the Eastern Typical Area

Table 3-7 Municipal Solid Waste Components in the Middle Typical Area


in the Middle Typical Area

Table 3-9 Municipal Solid Waste Components in the Southern Typical Area


in the Southern Typical Area

Table 4-1 Comprehensive Comparison Between Incineration Fly Ash Treatment

Technologies

Table 4-2 Comparative Analysis on Diverse Application Approaches of MSW

Incineration Fly Ash

Table 4-3 Boiling Points of Heavy Metals and Their Chloride

Table 4-4 Overview of environmental impact of different treatment

Table 4-5 The Daily Fly Ash Production and Disposal Technologies in Some Areas

Table 4-6 Leached Pollutants Concentration Limits of Fly Ash’s Cement Solidification

Table 4-6 Pollutant Concentration Limits of Stabilized Leach Liquid Prescribed by

Landfill Pollution Control Standards of Municipal Solid Wastes (GB16889-2008)

Table 4-8 Referential Limits of Heavy Metal Content from Raw Materials in the Kiln

Table 4-9 Maximal Heavy Metal Adding Volume

Table 4-10 Heavy Metal Content Limits from Cement Clinkers

Table 4-11 Heavy Metal Content Limits Leached from Cement Clinkers

Table 6-1 Features of Exhaust Gas Treatment Flow

Table 6-2 Residue Generation Mechanism and its Properties

Table 6-3 Fly Ash Generation Ratio

Table 6-4 Measurement Result of Heavy Metals in Soot and Dusts (unit: mg/kg)

Table 6-5 Exhaust Gas Treatment Methods of Incineration Plants under Survey


xii

Table 6-6 Properties of Fly Ash of Incineration Plants in Tokyo Metropolitan Area

Table 6-7 Thermofusion Characteristics

Table 6-8 Result of Crucible Test (unit:%)

Table 6-9 Annual Average Value of Bottom ash, Sludge and Fly Ash Generated from

Incineration Plants in Tokyo Metropolitan Area

Table 6-10 Analysis Example of Fly Ash Properties

Table 6-11 Comparison of Notified Four Methods

Table 6-12 Ash Melting Method

Table 6-13 Treatment Methods of Incineration Fly Ash in Japan

Table 6-14 Recycled Amount of Fly Ash Estimated Based on Statistics of Japan

Table 6-15 Ministerial Ordinance for Specific Standard

Table 6-16 Technical Requirements for Fly Ash Treatment Facility, Sintering Facility

Table 6-17 Technical Requirements for Municipal Waste Final Disposal Site

Table 6-18 Changes of Incineration Treatment in European Countries

Table 6-19 Ranges of Total Content of Elements in MSWI Residues

Table 6-20 Leaching Limit Values for Hazardous Waste Acceptable at Landfills for Non-

hazardous Waste

Table 6-21 Leaching Limit Values for Waste Acceptable at Landfills for Hazardous

Waste

Table 6-22 Limit Values for Waste Acceptance in Landfill, as Per Decree N. 36/2003.

Parameter Unit Limit Value

Table 6-23 Limit Values in Eluate for Waste Acceptance in Landfill, as Per Decree N.

36/2003

Table 6-24 Emission Limits from the Netherlands Regulation as Part of the Soil Quality

Decree

Table 6-25 Waste Acceptance Criteria for Non-hazardous Mineral Waste in Denmark

Table 6-26 Limit Values for Content and Leached Amounts in Statutory Order

1662/2010

Table 6-27 Emission Limits from the Netherlands Regulation as Part of the Soil Quality

Decree

Table 6-28 Limit Values for Compliance Leaching Test for Granular Waste from Council

Decision annex 2003/33/EC)

Table 6-29 Limit Values for Compliance Leaching Test for Monolithic Waste from

Council Decision annex 2003/33/EC)


xiii

Table 6-30 Air Pollution Emission Control Unit in MSWIs

Table 6-31 Maximum Concentration of Contaminants for the Toxicity Characteristic

Table 6-32 Disposal or Reuse Technology of Fly Ash

Table 7-1 Disposal Situation of Incineration Fly Ash in Developed Countries

Table 8-1 Comparison and Selection of Different Fly Ash Disposal Schemes

Table 9-1 The Basic Situation of Heavy Metal Content in Fly Ash from China and Japan

Table 10-1 Heavy Metals Quality Standards of Co-processing Outcomes (Product)

Table 10-2 Standards for Air Pollution Control

Table 10-3 Leaching Toxicity Limits Requirements of Solid Wastes’ Vitrification

Products

TA-8963 PRC Final Report Chapter I

1

CHAPTER1 PROJECT INTRODUCTION

1.1 TA Background

1. Municipal Solid Waste (MSW) incineration is a latecomer in the PRC’swaste treatment market with the first plant built in 1989. However, PRC has

devoted in strengthening the construction of MSWIPs since then. The number

and capacity of MSW incineration plant (MSWIP) have been rising dramatically.

In 2015, there were 220 plants under operation, with total capacity of 216,000t/d.

Meanwhile, it’s estimated that the total number could be over 500 by the end of 2020.

2. Although incineration can reduce the volume of the solid waste dramatically

and get additional benefits such as electricity and heat production, it leaves

large amounts of fly ash and bottom ash. The percentage of fly ash generation

by weight of treated waste is about 3-4%, and that of bottom ash is about 20%.

Further reuse and/or sustainable final disposal are required for the fly ash and

bottom ash. In the PRC, pollution control of the MSWIPs and sustainable

management of bottom ash from MSWIPs have already been studied and

applied. However, sustainable use and final disposal of fly ash remain a

challenge. According to present standards such as Solid Waste Incineration

Pollution Control Standard (GB18485-2014) and Technical Code for Projects

of Municipal Waste Incineration (CJJ90-2009), fly ash is categorized as

hazardous waste and treated depending on waste composition and incineration

process. Few standards and regulations are made to the management and

reuse of fly ash. As a result, development of technical guidance,

standardization, and administrative regulations are urgently needed for fly ash

management in the PRC.

3. Solutions to safe management and reuse of fly ash and bottom ash have

been successfully developed and mainstreamed in countries such as Japan,

Germany, the United States, the Republic of Korea, and the United Kingdom.

Thus, fly ash policies and practices in these countries can be lessons to the

PRC MSWIPs.

1.2 TA Objective

4. Through the implementation of this TA project, it is expected to i) set up

technical standards for safe capture, processing, reuse, and sustainable


2

disposal of fly ash; ii) give policy recommendations and implementation action

plan for safe reuse and sustainable disposal of fly ash; iii) improve capacity on

technologies and to establish an information and service center on advanced,

sustainable MSWIP fly ash management in the PRC.

1.3 TA Scope and Activities

1) Project inception

Establishing a consulting expert team with rich experiences in relevant technical,

environmental, policy and regulatory programs;

Setting up the TA research frame and work plan of the project;

Drafting the inception report.

2) Development of technical standards for safe capture, processing, reuse,

and sustainable disposal of fly ash from MSWIPs

To assess state-of-the-art and proven technology and practices on fly ash

processing and reuse in the international context through literature review, web-

based resources and interviews, data collection and review, and demand analysis

for fly ash reuse materials;

To assess and review current application of technologies and practices in the PRC

on managing fly ash;

To develop draft technical standards for methods of safe and sustainable capture,

processing, reuse, and safe final disposal of fly ash;

3) Preparation of policy recommendations and implementation action

plan for safe reuse and sustainable disposal of fly ash from MSWIPs

To review and analyze policies and regulations in the international context and

compare with lessons learned for the PRC;

To develop draft policy recommendations for safe and sustainable reuse and

disposal of fly ash;

To prepare draft implementation action plan, including institutional framework,

rules, and responsibilities of the participating agencies.

4) Improvement of capacity on technologies and establishing an

information and service center on advanced, sustainable MSWIP fly ash

management in the PRC

To organize and carry out workshop for discussions and knowledge sharing on TA

findings with academies, MSWIP operators and regulators;

To train on and assist in developing a web-based database, and an information


3

platform for sustainable fly ash management in the PRC;

To organize final dissemination workshop and deliver TA findings to MSWIP

operators and regulators.

1.4 TA Deliverables

Based on the activities above, the following outputs will be delivered:

Inception report and workshop

Interim report and workshop

Draft final report and workshop

Dissemination workshop

Final report

Contents of the final report include:

Summary of TA implementation

Overview of current management status and characteristics of MSWI fly ash in

PRC

Overview of technologies and policies for reuse, recycle, treatment and disposal

of MSWI fly ash in PRC

Investigation and analysis of MSWI fly ash of typical incinerators in PRC

International best practices in sustainable management of MSWI fly ash

Challenges and recommendations for sustainable management of MSWI fly ash

in PRC

Web-based database and service platform for management of MSWI fly ash

TA-8963 PRC Final Report Chapter II

4

CHAPTER2 STATUS OF MUNICIPAL SOLID WASTE

MANAGEMENT AND CHARACTERISTICS OF FLY ASH

IN PRC

2.1 Municipal Solid Waste Management Status and

Development Process in China

2.1.1 Sources and Generation of Municipal Solid Waste

5. Municipal solid waste (MSW) refers to solid waste generated from daily life or any

activities that offer services for our daily life, as well as others prescribed by laws and

administrative regulations. It mainly includes kitchen waste, packaging materials,

wasted containers, leaves and weeds, wasted paper, dregs, night-soil, etc. On the

basis of its diverse sources, MSW can be classified into three categories- domestic

household waste, street cleaning waste and corporate waste. Acting as the main part

of household waste occupying the most complicated composition, domestic household

waste originates from those thrown by residents in their daily life. It mainly includes

easily degradable organics, ashes, sediments, plastics, paper fabrics and metals.

Street cleaning waste usually appears while cleaning the roads and streets, whose

composition resembles that of domestic waste but with much more sediments,

deadwood and defoliation as well as packaging materials, and with less easily

degradable organics and lower moisture content. corporate waste refers to waste

originating from the daily life and work of authorities, communities, schools and service

industries. The composition is characterized as simply-composed, low moisture

content, higher heat value and combustible, also varying with its different emergences.

6. It can be seen from above that MSW is an inevitable outcome of social

development and human life. The higher economic development and living standards’ improvement, the more MSW gradually produced. Statistics shows that in 2015, the

collection amount of MSW in China reached 191 million tons with a general collection

rate of 80%-100%. Figure 2-1 illustrates the progressive increase of China’s national waste collection amount from 1998 to 2015. It can be seen that from 1998 to 2009, the

national waste collection had increased from the original 113 million tons to 191 million

tons, hitting an average rate of about 4% year-on-year.

7. The main factors that affect MSW’s production and components include natural

conditions, climate conditions, seasonal variations, urban population, economic

development level, household income and consumption, living habits, urban

household gas rate, geographical conditions, etc. The higher urban economic


5

development and living standards’ improvement becomes, the more significantly the components of MSW will change - with an average organic content’s progressive ratio of about 7%, among which, the proportion between food waste and its organic content

will increase correspondingly. According to the statistical data, the content of food

waste in Beijing reaches 37% while that in Tianjin is 54%, Shanghai of 59%, Shenyang

of 62%, Shenzhen of 57%, Guangzhou of 57% and Jinan of 41%.

Figure 2-1 MSW Collection Amount in China Increases in Terms of Time

2.1.2 Components and Physicochemical Properties of MSW

8. MSW is a complexity composed of matters characterized by complex components,

high organic content and poor homogeneity, mainly including kitchen food, vegetation,

plastics, glasses, textiles, paper, metals, rubbers, sediments and other waste. Weight

percentage (the wet basis) is usually adopted to represent MSW’s physical components and its physicochemical properties parameters include moisture content,

amount-weight, elemental composition, devolatilization, heat value, etc., which varies

with the change of the property and proportion of waste components. Table 2-1, Table

2-2 and Table 2-3 illustrate MSW’s physical components, the chemical elements content of common waste components and its physicochemical properties in major

cities at home and abroad.

9. It can be seen from Table 2-1 that MSW’s organic content is much higher than its total inorganic content, reaching over 80%. Its physical components greatly differ in

diverse regions - MSW’s paper content is relatively higher in Europe and America while food content occupies a larger proportion (64%-84%) among the total MSW’s organic content in Beijing, Shanghai and Dalian. The predominant features of MSW in China

are high food content, high moisture content as well as high production.


6

Table 2-1 Physical Components of MSW in Major Cities of PRC and Abroad

Components (%) New

York Paris London Beijing Shanghai Dalian

Food 22 00 28.80 28.00 56.10 58.55 73.39

Paper 44.80 25.30 37.00 11.76 6.68 3.37

Glasses 11.60 13.10 10.80 3.84 4.05 2.56

Metals 8.00 4.10 6.00 1.69 2.00 0.51

Plastics 5.10 14.30 5.20 12.60 11.84 5.66

Textiles 4.00 7.10 3.40 2.75 2.26 1.63

Inorganic Matters 4.50 7.30 9.60 8.32 7.54 4.14

10. Table 2-2 shows that the chemical elements constitution of MSW’s components are significantly distinctive, with C, H and O as its main elements and less N, CI as

well as S. During MSW’s biological treatment process, organic C and N offer abundant nutrition and energy for microorganism; while in the incineration treatment process,

MSW with higher CI and S content will produce dioxins and sulfur oxides and cause

terrible environmental pollution or much more fuel gas treatment expenses for pollution

reduction.

Table 2-2 Content of Common MSW Compositions

Name W(N) W(C) W(H) W(O) W(Cl) W(S)

Comprehensive

Waste 1.28 31.40 4.78 22.98 0.44 0.11

Paper 0.31 38.72 5.57 40.64 0.17 0.09

Textiles 0.66 43.33 5.91 41.35 0.23 0.10

Plastics/Rubbers 0.35 60.59 9.80 7.29 0.23 0.14

Woods and Bamboos 0.51 44.65 6.12 41.80 0.05 0.05

Leaves and Grasses 1.67 34.54 5.11 30.86 0.70 0.18

＞15mm 1.79 26.48 3.56 22.44 0.42 0.12

15mm 0.80 16.96 1.92 15.37 0.14 0.06

11. It can also be seen from Table 2-3 that the wet basis’ low heat value of any components is far lower than the dry basis’ low heat value, which means moisture content has great influence on the waste’s low heat value - the higher the moisture

content is, the lower the heat value becomes. Besides, the waste of too low heat value

is not suitable or not beneficial for incineration treatment.

MSW’s physical components, chemical elements constitution, moisture content as well


7

as its heat value determine its treatment and the judgement of resources utilization.

MSW with high moisture content and perishable food waste should choose the

biological treatment (anaerobic digestion) to dispose the waste and meanwhile

generating power or heating with methane’s heat energy. In case of high organic

content but low moisture content, MSW should be disposed in the way of pyrolysis or

incineration and generate power or heat with its heat energy.

Table 2-3 pH, Moisture Content, Value Heat and Ash Content of Common MSW

Components

pH, Moisture

Content Heat Value and Ash Content

pH Moisture

Content(%)

Dry Basis

Low Heat

Value(J/g)

Wet Basis

Low Heat

Value(J/g)

Dry Basis

Ash

Content(%)

Wet Basis

Ash

Content

(%)

General Waste 7.83 50.73 14653 4565 49.71 31.79

＞15mm 7.78 55.99 13430 3874 58.51 24.29

15mm 8.02 38.25 7088 2972 80.88 48.31

Leaves and

Grasses 7.50 68.23 16840 3239 47.45 15.32

Paper —

— 43.50 19936 8409 23.33 11.13

Textile —

— 42.98 19022 7511 19.55 9.08

Plastics/Rubbers —

— 40.17 20848 11157 44.55 23.77

Woods and

Bamboos

—

— 22.51 23648 17057 17.37 12.84

2.1.3 Characteristics of Rural Solid Waste in China

12. The rural population of China accounts for 80% of the total population in the

country, and the amount of rural waste output is about 150 million tons annually. The

following is the Chinese Academy of Environmental Sciences in 2014 on China's rural

waste production and composition of the relevant statistics.


8

2.1.3.1 Per Capita Production of Rural Solid Waste in China

13. With the constant development of economy, the income status of peasants in

China has been continuously improved, and the consumption patterns of peasants

have undergone significant changes. Thus, the composition and emission of rural

domestic waste have also formed different new features in the past. Industrial products

are increasing in the lives of peasants, and the composition and content differences

between domestic waste and urban areas are shrinking. In the meantime, the total

amount of domestic waste in rural areas has also increased year by year. The average

daily amount of domestic waste in rural areas is 0.8 kg per day, and the amount of

domestic waste in rural areas is nearly 300 million tons per year. In general, the

composition of domestic solid waste in rural areas is mainly affected by consumption

level of peasants, energy structure and seasonal changes.

14. The per capita amount of solid waste per capita varies widely in different regions,

with 0.77 kg / d in the east, 0.98 kg / d in the middle and 0.51 kg / d in the west, 0.66

kg / d in the south, and 1.01 kg / d in the north, which may be related to the economic

level and population distribution in different regions.

2.1.3.2 Composition of Rural Domestic Waste in China

(a) The Main Types of Rural Domestic Waste

Harmful Waste,

1.73%,

Inorganic Waste,

41.16%

Recyclable Waste,

18.67%

Organic Waste,

38.44%


9

(b) Rural Domestic Waste Components

Figure 2-2 China's Rural Domestic Waste Components

15. Due to changes in people's consumption structure and income level, solid waste

components are also complex and volatile. The coarse component of the solid waste

component can be divided into four categories: organic, inorganic, recyclable waste,

and harmful waste. Subdivisions can be divided into kitchen waste, Ash residues,

paper, metal, glass, cloth, plastics and others. Figure 2-2(a) shows that the main types

of domestic solid waste in rural China are mainly organic and inorganic types, of which

38.44% are organic and 41.16% are inorganic, Followed by 18.67% recyclable waste,

and 1.73% harmful waste. Figure 2-2(b) shows that the domestic solid waste in rural

areas of China is mainly residual dirt with complex composition, accounting for 42.38%

of the total amount of waste, mainly including soil residue, fuel fly ash, construction

waste, etc., followed by kitchen waste, accounting for 35.97% of the total amount of

solid waste, whose ingredients are most complex, including leftovers, oil dirt, animal

and plant removal and so on. The remaining parts mainly include plastics 7.10%, paper

4.82%, cloth 2.86%, glass 2.45%, metal 0.62%, and other domestic waste 9.58%. The

content order of the components is ash> kitchen> plastics> other categories> paper>

glass> cloth> metal.

2.1.3.3 Comparison of Domestic Waste between Rural area and City in China

16. In the past, domestic waste in rural areas of China mainly consisted of vegetables,

post-dinner solid waste and paper-based products. However, with the rapid economic

development in China, living standards in rural areas also increased significantly in

recent years, thus leading to a great change of rural living habits. A variety of plastic

bags and disposables waste gradually increased, such as disposable items, old

clothes and all kinds of discarded small appliances and other substances not easy to

degrade.

Kitchen waste, 35.97

Ash residues, 42.38 Paper, 4.82

Metal, 0.62

Cloth, 2.86

Plastics, 7.10 Others, 9.58

Glass, 2.45


10

Table 2-4 Contrast of Domestic Waste between Rural Area and City

Waste

Amount

Waste

Sourc

e

Waste

Component

Waste

Property

Transpor

tation

Difficulty

Environme

ntal

Awareness

Waste Impact Environmen

tal Digestion

Capacity

Current

Situation

Processing

Effect

City More, rapid

increasing

Centralized

Inorganic matters,

kitchen organic

and waste

Large

recovery

amount

Easy High,

awareness

of danger

Population,

economy, fuel,

consumption

structure, city

characteristics

Have no

ability to

digest within

the city

Centralized

processing

Harmless,

can prevent

secondary

pollution

Rural

Area

Less, rapid

increasing

Centralized

More organic and

inorganic , less

waste

More

available

matters

Difficult Poor, not

clear harm

Not enough

awareness of

harm

Outdoor have

some ability

to digest

No special

treatment

Destroy the

ecological

environment


11

Table 2-4 compares the characteristics of municipal solid waste and rural household

waste in China. The characteristics of rural domestic waste are as follows: 1) The

output is rapidly increasing, and the domestic waste caused by the increase of

consumption also gradually increases; 2) The uneven distribution of waste resulted

from the uneven distribution of residents; 3) The composition is more and more

complex. There are various kinds of household waste in rural area. The proportion of

domestic waste varies greatly and varies constantly. It contains not only kitchen waste,

peel and crop stalks, but also various types of plastic bags that are difficult to degrade,

And other industrial, construction waste and some residual pesticides, used electrical

appliances and batteries; 4) Varying greatly with the seasons changing. There is a

clear difference in the number of domestic rubbish in different seasons, and the

number and composition of rubbish in each season has a stable regularity. These

reasons make the centralized management of rural household waste difficult.

2.1.4 Comparative Analysis on Characteristics of Solid Waste between China and Abroad

According to the literature, comparing with the main components of domestic waste in

the United States, Germany, Italy, Japan, Britain, France, India, Thailand, Brazil and

other countries in China as Beijing, Shanghai, Wuhan, Guangzhou, Hangzhou and

Shenzhen (As shown in Table 2-5). The results show that the developed countries

such as the United States, Germany, Italy, Japan, Britain and France all occupy the

largest proportion of paperboard in their household waste, followed by the kitchen

waste and others. In China and some developing countries such as India, Thailand,

Brazil, the largest proportion of their household waste are kitchen waste. This may be

related to the level of economic development. In relatively developed countries,

people's living standards are higher, and the kitchen waste proportion has been greatly

reduced; In contrast, in developing countries, the people's living standards are so low

that many areas are also struggling to get enough food and clothing, therefore, the

proportion of kitchen waste in their household waste is high. In addition, there is almost

no Wood and Bamboo species in domestic waste in the United States, Germany, the

United Kingdom and France. However, in China, Japan, India, Thailand, Brazil, Italy

and other countries, wood waste still occupies a certain proportion. In western

developed countries, the proportion of metal in the domestic solid waste occupies a

high proportion; while in Chinese urban solid waste, the proportion of metal is relatively

low. These differences may be related to people's living habits in different regions.

Table2-5 Domestic Waste Component Comparison at Home and Abroad

Country/City

Domestic Waste Component Ratio /%

Kitchen

Waste

Paper Wood

and

Bamboo

Plastic Fabric Metal Glass Others

United 22 47 0 5 0 3.0 3.0 20.0


12

States

Germany 16 31 0 4 2.0 5.0 13.0 29.0

Italy 31 28 4 14 4.0 3.0 8.0 8.0

Japan 17 35 4 18 6.0 4.0 9.0 7.0

Britain 25 31 0 8 5.0 8.0 10.0 13.0

France 15 34 0 4 3.0 3.0 9.0 31.0

India 49 0 10 0 7.0 0 35.0 0

Thailand 45 13 6 10 11.0 0 15.0 0

Brazil 52.0 19.0 1.0 15.0 6.0 3.0 2.0 2.0

Beijing 51.8 5.4 5.8 10.4 3.0 1.0 5.4 17.2

Shanghai 56.1 4.6 11.6 8.6 2.3 0.9 2.9 13.0

Wuhan 54.2 9.5 1.6 1.9 12.7 0 9.3 10.8

Guangzhou 61.0 6.4 2.4 17.5 4.3 0.8 3.0 4.6

Hangzhou 58.2 13.3 2.6 18.8 1.5 1.0 2.7 2.0

Shenzhen 59.4 11.0 0 14.0 3.9 0 5.0 6.7

17. By contrast, we can find that China's municipal solid waste mainly consists of the

following characteristics:

18. First, high content kitchen waste in domestic waste. Among the domestic waste

components of the major cities in China, the proportion of kitchen waste is over 50%,

which is the most important component of domestic waste. The high water content of

kitchen waste poses a series of problems for its follow-up treatment. On the one hand,

high water content leads to a reduction of waste heat value; on the other hand, high

water content occupies sanitary landfills and leads to large leachate production.

Therefore, a high percentage of kitchen waste should be classified and collected, and

be treated separately;

19. Second, high content of recyclables in domestic waste. Although many Chinese

families have a tradition of collecting and selling recyclables such as cardboard,

newspapers and cardboard boxes, the recyclables flowing into the city collection and

transportation system, such as paper, plastic and glass, Metal content is still high,

which can be seen from Table 2-4. If this part of the resources can be recycled and

reused, it will be able to effectively reduce the amount of rubbish and save the primary

energy exploitation.

2.1.5 Treatment and Disposal of MSW

20. The constitution of MSW’s components is influenced by the region’s economic development level, natural conditions, living habits, etc. while such constitution is the

essential factor that determines the treatment and resources utilization. However,

MSW treatment and disposal are also restricted by the economic development level,

technology level, natural geographical conditions, etc. Different countries, even

different regions in the same country adopt distinctive approaches and techniques for


13

MSW treatment. Currently, optional waste treatment methods contain sanitary landfill,

aerobic compost, incineration, anaerobic fermentation, gasification, pyrolysis,

biotransformation (such as earthworm biological treatment), comprehensive treatment,

etc. The MSW treatment technology in China mainly employs sanitary landfill,

incineration and other treatment technologies (such as compost, etc.).

21. Comparative treatment analysis on three common waste - sanitary landfill,

incineration and compost - is shown as Table 2-6.

Table 2-6 Comparison of Three Waste Treatment Methods

Item Sanitary Landfill Compost Incineration

Technological

Reliability

Mature and reliable,

known as common

technology

Reliable, with practice

experience

Relatively reliable,

known as mature

technology overseas

Area Relatively large,

500~900m2/t Medium, 110-150m2/t

Relatively small, 60-

100m2/t

Applicable

Condition

With no strict

demands for waste

components

Over 40% of

biodegradable

organism

Low heat value

higher than

4180kJ/kg

Secondary

Pollution

Secondary pollution

on both water and air

Slight pollution on

soil, surface water

and air

Grave air pollution

Resources

Utilization

Methane power

generation, heating

Composted manure

used for fertilization

Fuel gas, oil power

generation, heating

Final

Disposal

Belonging to final

disposal itself

Sediments requires

landfill

Sediments requires

landfill

Treatment

Cost

26-45 yuan/t

(secondary emission

standard)

35-40 yuan/t

(dynamic compost) 50-90 yuan/t

22. The technology development of MSW’s sanitary landfill in China was relatively late and treatments like high-temperature compost and naked pile-up in suburban areas

(the so-called natural attenuation landfill site) were the main choices, without any

standard landfill site in the early 1980s. In the middle and late 1980s, naked waste pile-

up brought plenty of mosquitos as well as flies, making everywhere filled with reek

while landfill leachate was not properly disposed and flew randomly - all these had

polluted the environment badly. However, such situation didn’t conform to the cities’ rapid development and could never meet the public’s environmental requirements.


14

Therefore, since the middle and late 1980s, Chinese government initiated the planning

and building of a standard MSW landfill. Hangzhou Tianziling Waste Treatment Plant

was the first standard sanitary landfill plant in China at that time. While it came to the

middle and late of 1990s, the country placed more emphasis on environmental

sanitation and invested more on waste treatment, successively building sanitary landfill

plants for large and middle cities. As shown in Figure 5-6, the number of sanitary landfill

plants built in China was stably increasing over time - from 324 plants in 2006 to 660

in 2015.




15

23. Since the establishment of China’s first MSW incineration power plant - “Shenzhen Qingshuihe Waste Incineration Plant” - in 1989, incineration treatment for MSW had

been formally introduced to China. Till 1997, the self-developed waste incineration

power plant of circulating fluidized bed had been successfully built in Hangzhou,

indicating that China’s MSW incineration treatment technology had entered to a new home-made era. However, local governments didn’t start to pay attention on the application of waste incineration power technology until 2001. From 2001 to 2005,

about one third provinces built their first local waste incineration power plant and

brought it into operation, marking China’s first waste incineration power plants’ construction hot. Encouraged by “The ‘Eleventh Five-Year’ Plan on the Facilities Construction for Domestic Cities’ MSW Harmless Treatment” issued in 2007, the

number of MSW’s incineration treatment in 2009 had increased 30% compared to that in 2008. “The ‘Twelfth Five-Year’ Plan on The Facility Construction for Domestic Towns’ MSW Harmless Treatment” highlighted, “during the 12th five-year period, over 35% of

harmless MSW treatment chooses incineration while 48% from the eastern areas

makes the same choice as well.” Over 20 years’ development, the incineration technology nationwide had been greatly promoted with its market share increasing

rapidly. As shown in Figure 2-5 and 2-6, by the end of 2015, there had been 220 MSW

incineration power plants being built and put into operation, with a total treatment scale

of 189,000 tons/day and a total installed capacity of 3890MW.

Figure 2-5 Number of MSW Treatment Facilities in PRC


16

Figure 2-6 Treatment Capacity of Different MSW Treatment Facilities

Figure 2-7 Treatment Capacity of Different Treatment Methods in China (2015)

24. With the development of social and economic technology in China, the proportion

of diverse waste treatment methods have been greatly changed - the proportion of

sanitary landfill and compost have been gradually decreasing while that of incineration

have increased slowly. Figure 2-6 indicates the amount change of the total harmless

MSW treatment, sanitary landfill as well as incineration and compost from 2003 to 2015.

25. It can be analyzed from Figure 2-6and Figure 2-7 that from 2003 to 2015, China’s harmless MSW treatment amount had been gradually increasing, from 75.447 million

tons to 180.13 million tons, among which, the harmless treatment amount of sanitary

landfill had increased successively from 64.04 million tons to 114.813 million tons just

with a relatively smaller proportion; that of incineration had increased significantly from

3.699 million tons in 2003 to 61.755 in 2015, with its treatment capacity occupying 34%

of the harmless treatment of MSW in Chinese cities and was expected to exceed 50%

within 2020. It was the result driven by rapid social and economic development,

significant increasing of waste production amount, and worsen waste crisis as well as

Sanitary

Landfill

64%

Incineration

34%

Others

2%


17

other factors.

26. Since incineration requires small areas, short treatment period and brings

significant waste decrease, relatively absolute harmlessness and high-efficient energy

recycling, it will gradually become the predominant technology for China’s MSW treatment.

2.2 Generation and Characteristics of MSWI Fly Ash

2.2.1 Physical and Chemical Characteristics of MSWI Bottom Ash

2.2.1.1 Waste Incineration Ash Classification

27. Figure 2-8 shows that residues from incineration of municipal solid waste are

classified as Bottom ash and Fly ash, consisting primarily of metal oxides, hydroxides

and carbonates, sulfates, and phosphoric acid Salt and other substances. Bottom ash

is discharged from the hearth rear incineration residue, whose specific content is

related to the type of waste, incinerator type, burning conditions. Fly ash refers to the

fine particles collected by the air pollution equipment, usually through the cyclone dust

collector, electrostatic precipitator or bag filter collected by the neutralizing reactants

such as CaCl2, CaSO4 and incomplete reaction of alkaline agents such as Ca(OH)2

and so on. The physical and chemical properties of MSW incineration ash residues are

related to the incineration devices and working conditions of the incineration plant. Ash

generated by grate incinerators accounts for about 15-20% of MSWI, of which fly ash

accounts for 3-5% of MSWI, accounting for about 5% of ash residues, bottom ash

accounting about 95% of residues; the ash generated by the fluidized bed incinerator

accounts for about 20-25% of the total amount of MSWI, wherein the fly ash accounts

for more than 10% of the amount of MSWI, accounting for about 20% of the ash residue,

and the bottom ash accounts about 80%.


18


28. Waste incineration fly ash is contaminated with waste incineration pollutants,

mainly inorganic salts, heavy metals and dioxins, and is defined as hazardous waste.

Therefore, to completely decontaminate waste, fly ash must be properly disposed of.

The general bottom ash is non-toxic and harmless to the current standards in China.

It can be paved, filled and piled up. The study found that the bottom ash of the

composition of a variety of complex materials, bottom ash in the melting block and ash

leachate heavy metal concentration is very low, far less than the standard identification

of solid waste leaching toxicity, which can be considered basically no toxicity.

Therefore, the bottom ash can be sent directly to the landfill for landfilling, or used as

a roadbed and building material without causing any environmental damage. As

opposed to fly ash, the bottom ash has the characteristics of composition of diverse

and complex, small toxicity, in accordance with the general solid waste treatment.

Bottom ash is more in line with the many technical requirements for aggregate and

gravel, and its heavy metal leaching is small, low organic content, suitable for recycling.

2.2.1.2 Physical Property of Bottom Ash

29. Bottom ash (also known as the bottom slag) is the main part of ash residues,

accounts for about 80-90%(by mass) of residues. Bottom ash is an inhomogeneous

mixture of slag iron and other metals, ceramic fragments, glass and other non-

flammable materials, and unburned organic materials. When the bulk of the material


19

is removed, it looks similar to porous, light gray sand and gravel. Electron microscopy

results showed that there are many holes in the bottom ash, very rough and rugged

surface with irregular angular, high porosity, and relatively large pore diameter. There

is no trace of melting and particle binding on the microstructure, which is the product

of bulk inorganic materials that undergo calcination at high temperatures in the furnace.

30. Bottom ash moisture content of 18.9%, water absorption was 14.97%. The bottom

ash particle size distribution mainly concentrated in the range of 20-50 mm (61.1-

77.2%), less than 0.074 mm particles less than 0.6%, and the bottom ash density was

1.17-1.54g/cm3, which was only 81% of sand density, Bottom ash friction angle up to

46.5°, and have the same order of magnitude of permeability with sand. Basically,

bottom ash meets the grading requirements of road building materials (aggregate,

graded gravel or graded gravel, etc.), which require that the material with uniform

grading is generally better stability, and the compressive strength is larger, easy to

compaction to a state of high bearing capacity. It is pointed out that fine grained

particles have good frost resistance and this graded nature of bottom ash is beneficial

to its resource utilization.

2.2.1.3 Chemical Property of Bottom Ash

31. The study found that the major elements of bottom ash(referred to as

concentration>10000 mg/kg or 1%) were O, Si, Fe, Ca, Al, Na, K and C. Bottom ash

contains a large number of soluble salts, with 3%-14% solubility.

32. The study on the leaching toxicity of bottom ash found that the concentration of

heavy metals in the bottom ash leachate is very low, which is far less than the

identification standard of leaching toxicity of solid wastes and can be regarded as

basically non-toxic. The harm to the environment caused by disposal or utilization is

not significant . From Table 2-7, it can be seen that most of the low-boiling heavy

metals and chlorides enter the fly ash when the incinerator hearth temperature is

between 800 and 1000 °C, which makes the fly ash a hazardous waste, and the flue

gas treatment system collect, store, and then transport for safe handling separately.

Therefore, the content of heavy metals in the bottom ash is relatively small. Chinese

regulations show that the bottom ash is general solid waste, and incineration fly ash is

classified as hazardous waste and needs to be handled separately.

Table 2-7 Melting Point and Boiling Point of Several Heavy Metals and Their

Compounds(℃)

Element Simple Substance Oxide Chloride Melting Point

Boiling Point

Melting Point

Boiling Point

Melting Point

Boiling Point

Zn 419 907 1975 2360 290 732 Pb 327 1749 886 1470 501 950 Cu 1083 2567 1326 2000 620 993 Cr 1857 2672 2435 3000 877 947


20

Cd 321 767 1426 1500 570 960 Ni 1455 2730 1955 1984 1001 1980 Hg -39 357 500 Uncertain 275 301

2.2.1.4 The Danger of Bottom Ash

33. As can be seen in Table 2-8, the main components of fresh bottom ash are slag,

as well as ceramic fragments and masonry pieces, glass, iron wire and other metals

and unburned substances. The melting block accounted for about 60% of the total

mass, followed by glass、ceramic fragments 15%, non-ferrous metals and ferrous

metals about 20%, about 1% of organic matter also found, indicating the bottom ash

combustion is not sufficient , So easily volatile metal elements such as Pb, Zn and Cd

will remain in the bottom ash. And non-volatile metal elements such as Cu, Cr, Ni and

Mn remain in the bottom ash. Therefore, while most of the bottom ash leaching toxicity

test results show that the concentration of heavy metals in the bottom ash leachate is

very low, far below the identification criteria for solid waste leaching toxicity, however,

trace amounts of heavy metals are still present in the bottom ash, making the bottom

ash potentially threatened solid waste.

Table 2-8 The Physical Composition of MSWI Bottom Ash from Somewhere

Component Glass、Ceramic

Fragments

Magnetic Metal

Non-Magnetic

Metal Organic

Melting Block

Total

Proportion/% 15.1 11.4 8.1 1.2 64.2 100

2.2.2 Characteristics of Generation and Pollution of MSWI Fly Ash

34. Waste incineration is usually composed of various complicated thermal and mass

transmissions such as pyrolysis, melting, evaporation and chemical reactions,

producing a great amount of fuel gas which is required to be discharged after standard

APC treatment. Fly ash refers to those solid particulates collected from the fuel gas

purification system and utilization system of waste heat recovery (such as heat

recovery boiler, etc.) via dust collectors (cyclone dust collector, electrostatic collector,

or bag collector), which contains plenty of hazardous substances such as heavy metals

and dioxins.

35. Since incineration fly ash is the by-product produced from MSW incineration

process and exists in accompany with MSW. Its production amount must increase in

terms of the increasing of the scale and treatment capacity of MSW incineration

treatment. Figure 2-9 indicates that the amount of incineration fly ash from MSW had

increased successively from 2006 to 2015 and the incineration amount in 2015 was

about 61 million tons while the fly ash amount reached 3.95 million. The total amount

of hazardous waste was over 30 million tons in 2015 released by environmental

statistics with the amount of visible fly ash accounting for 13% of the total.


21

Production of Fly Ash (10,000 tons) with years

Figure 2-9 Fly Ash Production Amount from 2010 to 2015

2 Characteristics of Incineration Fly Ash from MSW:

(1) Huge production. MSW incineration has two mainstream incinerator types in

China, including mechanical grate incinerator and fluidized bed incinerator, with its

treatment capacity accounting for 2/3 and 1/3 respectively of the total capacity. The

former produces less fly ash, about 3%-5% of the total amount from the incinerator

while the later produces more, about 10%-15% of the total amount from the incinerator.

(2) Abundant heavy metals and dioxins. Most of the heavy metals and dioxins

from MSW incineration fuel gas will be intercepted by the purification system, leading

to them enriched in fly ash. Fly ash is therefore a significant “assembly” of heavy metals

and dioxins, also hazardous waste listed into “National Hazardous Waste Inventory”, which is applicable to mechanical grate incinerator as well as fluidized bed incinerator

with no need to further identify its properties. Such properties must be explicitly upheld,

or it will bring about the environmental supervision and market competition of MSW

incineration into chaos.

(3) High content of volatile elements. The properties of incineration fly ash from

MSW change in accordance with the change of waste components, season,

incineration condition, fuel gas purification level, etc. However, its main chemical

components, such as calcium, silicon and aluminium can be used as the material basis

for construction materials’ recourses utilization if they are approaching closely to

ordinary Portland cement. Besides, high content of volatile elements in fly ash such as

chlorine, sulfur, potassium and sodium greatly affects its treatment and utilization. In

particular, the incineration of chlorine containing plastics and high salt content kitchen

waste in incinerator causes obviously higher chlorine content in China’s fly ash than countries such as Europe, America and Japan, which has greatly increased the

141163

225

286

329

395

0

50

100

150

200

250

300

350

400

450

2010 2011 2012 2013 2014 2015


22

difficulty of fly ash treatment and utilization. Hence, future technologies such as waste

sources classification and pre-sorting will change the components and property of

incineration fly ash from MSW.

2.2.3 Basic Physicochemical Properties of MSWI Fly Ash

36. Fly ash is a kind of irregular substance converged by particulates, de-acid reactant,

unreacted substance as well as condensate, with a rough surface, irregular angularity,

high porosities and a large specific area, making metals produced from waste

incineration easy to condense on its surface. Fly ash’s physical and chemical

properties vary with different types of incineration plants’ purification system.

2.2.3.1 Physical Properties

1) Fly Ash Physical Properties And Particle Size Distribution

37. As shown from Figure 2-10, fly ash sample is white or yellowish tiny powders with

large specific surface area. The

specific surface area is 4.8-

13.7cm2/g, and the thermal ablation

rate is generally between 0.35-

14.45%(w/w). Figure2-9 shows that

the particle size is basically normal

distribution trend between range of

0.05-700μm, the main distribution range of 2-700μm. The average particle size is 79μm and fly ash with a size range of

38.5-74μm taking up 50% of its total amount. Besides, fly ash size larger than 154μm or smaller than 30μm account for 11% and 8% respectively while fly ash size smaller

than 74μm reaches 73%. Compared with slag, its characteristics can be illustrated as

follows:

Figure - Fl Ash Photo


23

➢ Hygroscopicity:

38. To remove harmful fumes such as hydrogen chloride, etc. in the incineration

equipment, alkaline components like hydrated limes are injected to the waste gas with

an amount of 1-2 folds of the harmful components. Since fly ash contains calcium

chloride formed by the reaction of hydrogen chloride and hydrated limes, it is therefore

hygroscopic and easy to absorb moisture from the air to produce absorption and

solidification.

➢ Floatation:

39. The particle diameter of fly ash is much smaller than that of slag, from several

micrometers to hundreds of micrometers with a low apparent density of about 0.2 to

0.5. It has a large size and is easy to float.

2) Melting Characteristic Temperature

40. Melting characteristic temperature is an important parameter for heat treatment of

fly ash. Incineration fly ash softening temperature, deformation temperature and flow

temperature can determine the melting temperature range of fly ash. The three melting

characteristic temperatures of incineration fly ash were measured with reference to the

standard of the black metallurgical industry of the People's Republic of China (YB /

T186-2001): deformation temperature (DT), softening temperature (ST) and flow

temperature (FT). Table2-9 lists the melting characteristic temperature. It can be seen

that incineration fly ash flow temperature is very high, while the melting temperature is

1324 ℃.

Table2-9 Melting Temperature Test Result of Fly Ash (℃)

Softening Temperature Flow Temperature Melting Temperature

1068 >1477 1324

Figure - Size Distri utio of Fl Ash

Volu

me

Perc

enta

ge(%

)

Particle Diameter(μm)


24

2.2.3.2 Chemical Properties

41. Incineration fly ash is mainly composed of chemical compounds of Si, Al and Ca

and volatile metal chloride, with Ca, Cl, K, S and Si as its chief elements. This is quite

similar to the composition of general mineral elements and belongs to the system of

CaO - SiO2 - Al2O3 - Cl - SO3; It has many Cl, Pb, Cd, Sb and Se compounds and

monomer concentrates. Direct fly ash landfill will render soluble harmful components

opportunities to immerse into the underground water after rain saturation. Though the

heavy metals’ types and contents differ from each other, they still focus on Pb, Zn, Cu, Mn, Cr, etc. In addition to amorphous and glassy substances, there are also various

other compounds and mineral components in fly ash while NaCl, KCl, SiO2, CaSO4,

CaCO3, CaClOH, etc. make up the primary compound forms of incineration fly ash.

➢ As the temperature grows higher and higher, the fly ash’s loss on ignition is gradually increasing.

➢ With the heat-raising and time-extension of the melting, salts like SO3 and Cl

in the fly ash will greatly volatilize and the produced harmful gas like SO3 and

Cl2 will bring about heavy environmental pollution.

42. Table 2-10 presents the results of the X-ray fluorescence spectrometer analysis

of the major chemical compositions (oxides) of incineration fly ash.

Table 2-10 Chemical Compositions of Fly Ash(%)

Oxides CaO SiO2 Al2O3 TiO2 Fe2O3 Cl Content/% 49.98 7.39 1.58 0.97 2.16 14.54

Oxides Na2O K2O MgO P2O5 MnO SO3

Content/% 7.25 4.47 1.40 0.44 0.098 5.40

1) Heavy Metal Content and Chemical Morphology in Fly Ash

43. Although there are some differences in the types and contents of heavy metals,

Pb, Zn, Cu, Mn and Cr are the main ones. Table 2-11 shows the heavy metal content

of incineration fly ash, showing relative high levels of Zn, Pb, Cu and Sb in incineration

fly ash.

Table 2-11 Heavy Metal Content of Fly Ash(mg/kg)

Heavy Metal

Zn Pb Cu Sb Sn Ba Sr Cr

Content 5278.50 2251.40 1426.50 650.50 534.85 274.90 125.65 103.21

Heavy Metal

Cd Ni W As Co Mo Zr Hg

Content 96.97 73.25 22.14 20.34 21.43 17.14 11.17 9.45

Heavy Metal

Ag Bi Nb Ga Ce La Nd

Content 8.12 6.66 5.42 2.46 0.39 0.28 0.08


25

44. The magnitude of heavy metal toxicity in incineration fly ash is not only related to

its total amount, but also closely related to its chemical form. The bioavailability and

toxicity of heavy metals in the environment can not be fully characterized by the total

amount of heavy metals in the environment. The heavy metals that are absorbed by

the organisms and enriched are active in the environment. By analyzing the chemical

combination forms of heavy metals, we can more effectively identify the toxic effects

of heavy metals in incineration fly ash in the environment. Using the BCR continuous

extraction method, the final residue was digested according to the standard test

method (ASTMD6357-00a). and the concentration of heavy metals in each step of

extraction was determined by ICP-MS. Using this method to determine the chemical

forms of heavy metals in fly ash, the results are shown in Figure2-12.

Figure2-12 Chemical Combining Morphology of Heavy Metals in


45. It can be seen that the proportions of chemical forms of various heavy metals in

incineration fly ash vary greatly. Only a certain proportion of Pb and As exist as acid

extractable state in the six kinds of heavy metals, while Cu, Zn, Pb and Sb exist in the

residual form Mainly, indicating that Pb and As of incineration fly ash partly leached

out in a weak acid environment. However, Cd is mainly reducible, while As is mainly

oxidizable. This shows that heavy metals in incineration fly ash will have a certain

proportion of leaching under the conditions of oxidation and reduction, thus bringing

about environmental hazards.

Cu Zn Pb Cd As Sb0

20

40

60

80

100

120

140 酸可提取态可还原态可氧化态残渣态

分布

(%)

重金属Heav Metal

Dist

riut

io%

A id E tra ta le

Redu i le o idiza le Residue


26

2.2.4 Heavy Metal Leaching

46. Fly ash is abundant with harmful heavy metals such as Hg, Cd, Pb, As, etc., which

is because heavy metals with a relatively low boiling point would be captured into fly

ash after incineration and volatility and they are easy to leach out. Fly ash also

occupies high dissolved salt content with much more alkali metals and alkaline-earths

such as potassium, sodium and calcium than the slag. If improperly disposed, heavy

metals will gradually leach out under the effect of environmental factors such as acid

rain and enter to a fresh-new environment to pollute the underground water sources.

2) Mineral Analysis of Fly Ash

47. The use of X-ray diffraction instrument for the analysis of mineral morphology of

incineration fly ash, the diffraction pattern is shown in Figure 2-13. The analysis shows

that the crystals of incineration fly ash mainly exist in the form of SiO2, NaCl and KSO4,

and a small amount of calcite (CaCO3).

Figure 2-13 XRD Pattern of Fly Ash

48. The mineral phase in incineration fly ash can be divided into three categories:

chloride salts, mainly NaCl, KCl; incinerator flue gas purification process generated

substances, including sulfates and carbonates, such as CaCO3, CaSO4 and CaClOH;

Species formed by recrystallization of minerals during combustion in the

combustion process include glass phase materials, quartz, Ca-Al feldspar (Ca2Al2SiO7)

and aluminosilicates. Calcium cations are present in the form of complex silicates or

aluminosilicates, the composition of which varies widely depending on the combustion

conditions, and the compounds overlap in the spectrum. Some scholars using X-ray

photoelectron spectroscopy (XPS) found that the general aluminosilicate is mainly

10 15 20 25 30 35 40 45 50 55 60 65 700

1000

2000

3000

4000

5000

6000

3

3

3

3

55

55

5

77

7 666

6

6

6

6

6

6

1

1

1

19

9

9

9

9

9 Pb5O

8

2222

2

2

888

8

8

8

4

4

4 8 Ca(OH)2

Inte

nsit

y

2θ °

5 KCl 4 NaCl

2 CaCO3

3 CaSO4

6 CaClOH

1 SiO2

7 Ca2Al

2SiO

7


27

distributed in the fly ash particles inside and Na, K, S, Zn are distributed in the fly ash

particles surface. Fly ash particles from the polycrystalline polymer, amorphous glassy

substance, amorphous glass up to 70%, these amorphous and crystalline substances

are enriched in volatile elements such as heavy metals, which will be released soon in

acid or Alkaline environment.

3) Chemical Composition of MSWI Fly Ash

49. Fly ash components of six representative MSWI power plants in Tianjin (Plant No.

1, 2, 3, 5, 6) and Beijing (Plant No. 4), measured in August (A) or September (S) of

2016, is illustrated as Table 2-12. Main components are Fe2O3, SiO2, Al2O3, CaO and

MgO, for which the content is expressed by weight (w%), whereas contents of trace

elements (Zn, Cd, Pb) are expressed in mg/kg because its content is too small to be

express by weight percentage.

TA-8963 PRC Draft Final Report Chapter II

28

Table 2-12 Chemical Components of Fly Ash from Different Plants in Different Period

Plant No. – Date

(Day/Month)

Fe2O3

w% SiO2

w% Al2O3

w% CaO w%

MgO w%

Total Main Components

w%

Na2O w%

K2O w%

Zn mg/kg

Cd mg/kg

Pb mg/kg

Cl w%

Sulfide w%

Total w%

1-26/A 1.29 15.73 4.4 38.77 3.64 63.83 4.27 3.42 4023 82.9 854 15.52 0.59 87.63

1-27/A 0.98 10.28 3.38 40.27 3.01 57.92 4.19 3.82 3998 91.6 949 19.7 0.37 86

1-29/A 1.19 12.25 3.84 40.21 3.19 60.68 4.08 3.59 4945 87.6 982 18.49 0.48 87.32

1-30/A 1.19 12.46 3.84 40.76 3.08 61.33 3.96 3.35 4491 77.4 842 17.66 0.36 86.66

1-31/A 1.04 11.15 3.56 33.26 2.64 51.65 3.16 2.87 3609 64.6 726 13.58 0.55 71.81

1-1/S 1.57 16.12 6.57 35.11 3.66 60.30 3.59 3.05 4442 69.5 893 14.14 0.32 81.4

1-2/S 1.15 11.92 3.62 39.04 3.27 59 4.15 4.08 4181 89.5 919 9.18 0.68 77.09

2-26/A 2.42 25.45 16.21 26.85 4.21 75.14 3.47 2.03 4677 34 606 4.02 0.82 85.48

2-27/A 2.61 26.48 12.99 24.84 3.88 70.8 3.46 2.02 4539 32.5 613 4.64

0.35 81.27

6.49 83.12

2-28/A 2.5 27.06 14.33 24.41 3.75 72.05 3.72 2.02 4224 26.6 589 5.1

0.68 83.57

6.78 85.25

2-29/A 2.47 26.99 14.71 25.06 3.91 73.14 3.19 2.02 4383 28.2 585 3.94

0.57 82.86

6.03 84.95


29

Plant No. – Date

(Day/Month)

Fe2O3

w% SiO2

w% Al2O3

w% CaO w%

MgO w%


w%

Na2O w%

K2O w%

Zn mg/kg

Cd mg/kg

Pb mg/kg

Cl w%

Sulfide w%

Total w%

2-30/A 2.37 23.24 14.23 25.22 3.58 68.64 2.99 2 4426 31.7 575 6.69 0.63 80.95

2-31/A 2.48 24 13.61 23.87 3.51 67.47 2.98 1.98 4645 29.7 585 6.78 0.58 79.79

2-1/S 2.35 27.38 14.56 22.53 3.66 70.48 2.72 1.86 4069 21.3 441 6.56 0.1 81.72

3-26/A 1.77 18.12 3.73 36.34 5.01 64.97 2.85 2.9 4717 48.3 1360 11.42

0.65 82.79

15.79 87.16

3-27/A 1.8 19.99 3.99 33.89 5.75 65.42 2.43 2.98 4975 50.3 1287 14.84 0.21 85.88

3-30/A 2.11 18.31 4.2 34.02 4.89 63.53 2.31 2.8 5139 50.1 1417 16.42 0.97 86.03

3-1/S 1.81 17.54 3.91 34.29 4.78 62.33 2.28 2.77 5157 46.3 1294 15.72 0.24 83.34

3-2/S 1.84 17.08 4 33.64 4.66 61.22 2.18 3.44 4391 49.3 1195 14.3 0.24 81.38

3-3/S 1.7 15.7 3.63 36.96 4.17 62.16 2.04 3.22 4660 55.5 1296 4.18 0.53 72.13

3-5/S 1.56 14.13 3.43 38.51 3.96 61.59 2.24 3.4 4575 50.6 1245 9.61 0.64 77.48

4-27/A 0.45 3.62 1.01 51.17 1.52 57.77 3.29 2.66 2996 63.5 634 13.11

0.38 77.21

16.84 80.94

4-1/S 0.59 7.01 1.68 49.73 1.91 60.92 3.42 3.12 3829 57.5 687 18.55 0.46 86.47


30

Plant No. – Date

(Day/Month)

Fe2O3

w% SiO2

w% Al2O3

w% CaO w%

MgO w%


w%

Na2O w%

K2O w%

Zn mg/kg

Cd mg/kg

Pb mg/kg

Cl w%

Sulfide w%

Total w%

4-3/S 0.52 5.19 1.36 48.93 1.73 57.73 3.75 4.2 3806 60.6 786 11.49 0.39 77.56

4-5/S 0.46 4.52 1.21 49.19 1.66 57.04 3.62 3.9 3798 76 745 19.59 0.15 84.3

4-7/S 0.52 5.23 1.37 50.06 1.77 58.95 3.75 4.06 3604 69.5 738 19.36 0.48 86.6

4-8/S 0.48 4.82 1.25 50.25 1.76 58.56 3.52 3.71 3452 77.7 749 17.69 0.45 83.93

4-9/S 0.52 4.72 1.43 47.36 1.71 55.74 3.66 3.86 3767 76 793 17.88 0.2 81.34

5-9/S 0.88 4.61 3.31 33.12 2.29 44.21 7.45 8.74 7546 194.8 2313 14.94 0.62 75.96

5-10/S 0.58 4.22 1.23 41.7 2.24 49.97 6.38 7.43 7067 174.3 2130 22.16 0.66 86.6

5-15/S 1.75 3.88 2.08 68.82 0.55 77.08 3.35 3.64 4282 107.8 1252 8.88 0.98 93.93

5-17/S 1.65 3.84 1.97 62.14 0.49 70.09 3.3 3.62 3991 94.5 976 13.14 0.47 90.62

5-22/S 3.69 10.42 4.39 53.26 1.51 73.27 6.08 4.16 2964 77.3 1140 11.86 0.83 96.2

5-23/S 3.68 10.31 4.38 53.33 1.51 73.21 6.08 3.98 3135 80.9 963 10.07 0.42 93.76

6-10/S 1.54 16.79 3.08 39.77 3.85 65.03 5.61 4.32 3569 68.9 1118 18.21 0.96 94.13


31

Plant No. – Date

(Day/Month)

Fe2O3

w% SiO2

w% Al2O3

w% CaO w%

MgO w%


w%

Na2O w%

K2O w%

Zn mg/kg

Cd mg/kg

Pb mg/kg

Cl w%

Sulfide w%

Total w%

6-11/S 1.09 8.24 2.3 40.89 3.23 55.75 5.4 4.43 3964 83.7 1149 22.12 0.29 87.99

6-15/S 1.35 9.55 2.64 42.24 3.45 59.23 4.6 3.67 3219 61.9 972 15.43 0.16 83.09

6-16/S 1.28 12.8 2.9 40.04 3.46 60.48 4.89 3.56 2588 81.2 777 18.92 0.48 88.33

6-19/S 1.38 11.95 3.11 40.07 3.88 60.39 5.16 3.84 2891 59.4 913 17.5 0.38 87.27

6-18/S 1.45 11.98 2.92 39.48 4.28 60.11 5.08 4.32 3726 68.4 1165 18.21 0.77 88.49

6-20/S 0.52 3.46 1.1 51.17 1.27 57.52 3.4 3.84 4453 100.3 1184 11.76 0.17 76.69


32

50. Pollution characteristics of fly ash samples from 15 MSWI plants in China were

investigated and analyzed. The results show that the total amounts of Zn, Pb, Cu, Cr,

Cd and Ni in 15 typical municipal solid waste incineration fly ash are 782.6-9901,

728.0-2162, 232.0-716.2, 83.67-525.0 and 140.7-378.63 mg/kg respectively.

Concentrations of Zn, Pb and Cu are substantially one order of magnitude greater than

those of Cr, Cd and Ni. The concentration orders ranged from large to small: Zn> Pb>

Cu> Cr> Cd> Ni; dioxin matters were all contained in MSW incineration fly ash samples.

1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF contributed significantly to the toxic equivalent

of fly ash samples, accounting for 16%-25% and 16%-28%, respectively, mainly due

to The concentrations and toxic equivalency factors of these two monomers are

relatively high compared to other monomers. The concentration of PCDDs in fly ash

samples ranged from 1.1 to 51ng/g and the average concentration was 37ng/g. The

highest concentrations of PCDDs in most samples were hexachlorodibenzodioxins

(HxCDDs) at a concentration range of 0.34-36ng/g and an average concentration of

22ng/g, accounting for 7%-25% of the total PCDDs and PCDFs concentrations.

2.2.5 Influence of Incinerator Type on Fly Ash Characteristics

51. The nature of incineration fly ash directly related to the type of waste, incinerator

type, incineration process conditions, flue gas purification processes and other factors.

Currently, there are three main types of boilers used in China's waste incineration

technologies: mechanical grate boilers, fluidized beds and other small incinerators (eg

small vertical boilers, small chain boilers and pyrolytic boilers). As of 2014, the number

of incineration plants using grate boilers, fluidized beds and other small incinerators

accounted for 60%, 37% and 3% respectively.

52. Here mainly summarizes two types, including the grate boiler and fluidized bed, in

China on the impact of incineration fly ash.

2.2.5.1 Oxide Properties of Grate Boiler / Fluidized Bed Fly Ash

53. The main oxide properties of the main grate boilers and fluidized bed incineration

fly ash in China are summarized and are given in ternary phase diagrams (see Figure

2-12(a) and Figure2-12(b)). The upper right corner of the phase diagram shows the


33

area where the major components of fly ash from 31 major coal-fired power plants in

China are located. The lower left corner of the phase diagram is the area where the

major components of limestone are located in the five major mining areas in Jiangsu.

As China uses mostly semi-dry flue gas purification process incinerator, the tail of a

large number of spray calcium, so incineration fly ash higher CaO content, followed by

SiO2 content, in Figure2-14(a), SiO2 does not exceed the limit of 50% , Al2O3 content

is the least. Fluidized bed incinerators can be blended with coal, although the relevant

regulations limit the proportion of coal blending not higher than 20%, however, in

practice, in order to maintain the stability of the combustion conditions, the proportion

of blending is often greater than the prescribed value. In the incineration process, the

content of SiO2 in the fly ash increases with the participation of coal. As shown in

Figure2-12(b), the content of SiO2 in the ternary phase diagram of incineration fly ash

is about 50% except one point at the lower left, which is obviously higher than that of

the grate boiler incineration fly ash, making the nature of fluidized bed incineration fly

ash close to the coal-fired fly ash. In addition, as the flue gas flow rate of the fluidized

bed is significantly higher than that of the grate boiler, some of the ash that should

have remained in the bottom ash is transferred to the fly ash. The result present as the

fluidized bed incinerator fly ash (15-20%) is higher than the grate boiler fly ash (3-5%).

Figure (a) Main Components Distribution

of Grate Boiler Fly Ash

Figure (b) Main Components Distribution

of Fluidized Bed Fly Ash

Figure 2-14 The Main Composition Distribution of Different Types of Fly Ash

2.2.5.2 Chlorine, Sulfur, Alkali Content of Grate Boiler/Fluidized Bed Fly Ash

54. Chloride salt in incineration fly ash mainly are in the form of NaCl, KCl and CaCl2.


34

Figures 2-15 and 2-16 show the Cl and SO3 contents of grate boiler and fluidized bed

incineration fly ash in our country. As can be seen from Figure 2-13, the chlorine

content of fly ash from grate boiler is higher, and the lowest and the highest values

were 0.88% and 30%, respectively, most of them distributed 10 -20% with an average

value of 15.41%. This was mainly related to the nature of domestic waste, working

conditions of incineration and flue gas purification equipment. The main source of

chlorine in incineration fly ash is a large amount of kitchen waste and plastic materials,

etc.. During the high-temperature heat treatment, chlorine salts will cause a large

number of heavy metals volatile. Chlorine content of fluidized bed incineration fly ash

is in smaller fluctuations, with an average of 1.71%, obviously lower than the grate

boiler fly ash, the reason is due to fluidized bed incineration with coal.

Figure 2-15 Cl Content of Grate Boiler/Fluidized

Bed Fly Ash

Figure 2-16 SO3 Content of Grate Boiler/Fluidized

Bed Fly Ash

Figure 2-17 K2O Content of Grate Boiler /Fluidized

Bed Fly Ash

Figure 2-18 Na2O Content of Grate Boiler /Fluidized

Bed Fly Ash

0 5 10 15 20 25 30 0

5

10

15

20

25

30

35

Cl C

on

ten

t(%

)

Fly Ash

Grate Boiler

Fluidized Bed

0 5 10 15 20 25 0

5

10

15

20

Grate Boiler

Fluidized Bed

SO

Co

nte

nt(

%)

3

Fly Ash

0 2 4 6 8 10 12 14 16 18 20 0

5

10

15

20

Grate Boiler

Fluidized Bed

Fly Ash

K2O

Co

nte

nt(

%)

0 2 4 6 8 10 12 14 16 18 20 0

5

10

15

20

Fly Ash

Na

2O

Co

nte

nt(

%)

Grate Boiler

Fluidized Bed


35

55. Figure 2-17 and Figure 2-18 for the incineration fly ash alkali content, K2O and

Na2O content close to each other, the average K2O and Na2O concentration of grate

boiler incineration fly ash 6.06% and 5.33%, the average content of fluidized bed

incineration fly ash 2.43% and 2.63 %, the content difference of alkali is less than that

of chlorine, sulphur in two type incineration fly ash.

2.2.6 Fly Ash Properties of Diverse Flue Gas Treatment Techniques

56. The direct factor that affects fly ash characteristics is the flue gas treatment

process. Most large-scale waste incineration plants adopt the approaches of dry/semi-

dry fuel gas treatment system and wet fuel gas treatment system and ash from the

scrubber reactant ash and bag collector is usually collected together. Therefore, the

mix incineration fly ash comes into being. Mix incineration fly ash contains the products

produced by the reaction with acid gas (such as CaCl2, CaSO4, etc.) and some other

unreacted alkaline agent (such as Ca(OH)2).

2.2.6.1 Characteristics of Fly Ash Processed via Dry/Semi-dry Flue Gas Treatment

57. Currently, dry/semi-dry treatment technique is applied to most purification systems

of municipal solid waste incineration plants (MSWIPs) in China.

58. Dry purification technique injects lime dust into the cooling tower’s outlet pipes via

the injecting system and the injected lime dust will then contact with acidic gas around

the sack dust remover to generate some solid compounds. Such compounds will be

captured and collected together with the fly ash by the dust remover afterwards. Since

alkaline solid can’t contact with gas for too long and the effect of mass transfer

performs badly, therefore, to improve the reacting speed, the actual alkaline solid used

reaches about 3-4 times more than the original amount required by the reaction

demand.

59. Semi-dry technique injects in lime solution with certain concentrations via the

sprayer to react with acidic gas and controls the reaction temperature through water

injection as well. Moisture evaporates through the absorption and neutralization

reaction process while fly ash in larger particles sinks to the bottom of the vessel to be

discharged. Fly ash in fine particles is then captured and collected by the dust remover.


36

It means that between the alkaline absorbent solution and acidic gas from flue gas, the

adequate mass and heat transfer will improve the efficiency, as well as drying those

reaction products and finally generating several manageable dry powder products.

Two times of the theoretical lime powder dosage is used and achieves a purification

efficiency of 95%-99%.

60. Chlorine from the fly ash mainly originates from waste plastics (mainly PVC

plastics), kitchen waste, waste rubber products, etc., among which, PVC plastics are

primarily organic while kitchen waste are inorganic. Heavy metals from fly ash mainly

originate from industrial solid waste mixed into MSW as well as batteries, pigments,

construction materials and other poisonous and harmful waste from MSW.

61. Dividing MSW into “harmful waste”, “recyclable waste”, “kitchen waste” and

“general waste” first and then incinerating those “general waste” will achieve the

reduction and recyclable utilization of waste sources. Firstly, the MSW entering to the

incinerator will be reduced and the production of incineration fly ash is therefore

reduced as well to alleviate f ly ash’s disposing pressure; secondly, the moisture

content will also be reduced to improve the waste incineration heat and temperature,

increasing the resources’ utilization efficiency and decreasing the generation of dioxins;

thirdly, the heavy metal content of the waste will be reduced as well so that there will

be less heavy metals in the fly ash. Obviously, sources classification can directly

reduce the dioxins’ generation matrix and breaks its forming condition. Meanwhile,

waste classification helps the incineration treatment to reduce the amount (reduce the

waste treatment amount), to reduce the emission (reduce the pollution emission

amount), to increase the quality (improve combustion operation) and to improve the

efficiency (improve power-generating efficiency), etc.

62. It has been proved that with the improvement of urbanization rate, MSW’s organic

content is increasing in general while the inorganic content such as sediments is

gradually decreasing. Besides, the average organic and inorganic content tends to

remain stable with less components changes; the proportion of recyclable materials

such as paper, plastics and rubbers has greatly increased, so has the waste utilization

value; there is also more combustible content with higher heat; as the gradual initiation

of waste bagging in various cities, rain erosion has been reduced and together with

the change of people’s living habits, waste’s moisture content will be gradually reduced.


37


63. Alkaline substances injected to the fuel gas via dry/semi-dry method are usually

lime which is used to remove harmful acid substances within the fuel gas such as HCI,

HF, SOx, etc. Produced fly ash contains reactant that comes from the reaction with

acid gas in the fuel gas (such as CaCl2, CaSO3, CaSO4, CaF2, etc.) and some

unreacted alkaline. Mostly fly ash is alkaline, pH up to 12.8. It occupies a high-level

calcium content and large fly ash production amount. Besides, since the mass fraction

of CaCl2 (the reactant of lime and HCI) in fly ash is relatively high, CaCl2 is therefore

soluble and heat-labile. If isn’t removed before, it will block the solidification and

stabilization of fly ash.

2.2.6.2 Fly Ash Properties via Wet Fuel Gas Treatment

64. Wet purification technique usually adopts electrostatic collectors to remove the

dust and reduces the fuel gas temperature to 60-70℃ in the quencher, then enters to

the wet scrubber to conduct alkaline cleaning process so that the acid pollution in the

fuel gas can be removed. The commonly-used absorption potion is NaOH solution and

a little Ca(OH)2 to avoid scaling. Wet de-acid purification has high efficiency and the


38

HCI removal rate reaches 99% while that of SO2 is over 90% as well. However, waste

water vented from the scrubber is supposed to be discharged after proper treatment

and the resulting sludge should be well-processed.

65. Different from the combinative technique of dry + dust removing and semi -dry +

dust removing and purifying, wet purification technique removes the dust with collector

and then applies wet technique to the pollutant. Incineration fuel gas from the

incinerator enters to the collector to remove particles from the fuel gas after cooling

down in the thermoregulation tower and therefore captures fly ash with higher acidity.

Currently, only a few MSW incineration fuel gas treatment and purification techniques

adopt the wet method. Incinerator in operation includes the waste incineration project

of Shanghai Laogang.

2.2.7 Effect of Combustion Conditions on Fly Ash Properties

66. Dioxins’ forming mechanism during the waste incineration process is divided into

two: one is precursor synthesis and diverse organic precursors are formed by

incomplete combustion and uneven catalytic reaction while the other is de novo

synthesis. Macromolecular carbon and organic chloride or inorganic chloride from the

fly ash matrix will be catalyzed into dioxins by certain catalytic components (such as

Cu, Fe and other transition metal or its oxide) under the temperature of 250-450℃.

Both mechanisms can be attributed to the fly ash surface heterogeneous catalytic

reaction at low temperature.

67. The incinerator operation’s effect on the production of dioxins: during the

incineration, improving the incineration condition and ensuring stable and complete

combustion can reduce the generation of dioxins. Favourable combustion condition

proposed by American EPA is one of the best approaches to control the discharge of

dioxins. The most optimal generation temperature of dioxins is 300-400℃, but dioxins

also exist while the temperature is over 500℃. However, dioxins will be completely

decomposed when the temperature is higher than 800℃. Modern waster incinerator’s

design adopts the principle of “3T+E” to control the discharge of dioxins, which means

to keep the combustion temperature (T) over 800℃; and to insert air for the second

time in the hot zone and fully agitate to increase the turbulence (T); to extend gas’s

retention time (T) in the hot zone (Time>2s) as well as to remain excess air (E). It


39

shows that the incinerator’s temperature is a significant parameter to regulate dioxins’

discharge.

68. In the incineration process, it is easy to produce pyrolysis of chlorine-containing

substances. In the flue gas of iron chloride, copper chloride and other catalytic role

with the flue gas in the HCl near 300 ℃, they will quickly re- Dioxins. If the incinerator

to take intermittent operation, it will inevitably increase the possibility of material

through the low temperature zone, increasing the chances of dioxin formation. As far

as possible, the continuous operation of the incineration system should be stabilized,

the number of start-up and shutdown of the incinerator should be reduced, and dioxin

should be reduced due to abnormal working conditions. At the same time, shorten the

cooling process of flue gas in the temperature range of 300-500 ℃, control the exhaust

temperature below 200 ℃, to avoid dioxin re-synthesis temperature zone.

2.2.8 Impact Prediction of Waste Classification on Fly Ash

2.2.8.1 Impact of Waste Classification on Fly Ash Dioxins

69. Fly ash is the main source of dioxins, and the metal, metal oxide or metal chloride

in fly ash promotes the formation of dioxins. The study found that the dioxin content of

fly ash is proportional to chlorine content. Fly ash is a by-product of waste incineration,

in which the content of each pollutant is directly related to the composition of the refuse.

(1) Waste Composition’s Effect on Dioxins

70. From the perspective of the forming mechanism, incinerating chlorine-containing

materials with metal salts is the main reason to produce dioxins. Organic chloride in

the waste includes vinyl chloride, benzyl chloride, pentachlorophenol and other

substances while the inorganic chloride is mainly chloride salt. Chloride donor reacts

with O2 and HCl in proper temperature under the catalysis of copper, iron, nickel, etc.

and produces dioxins via molecular rearrangement, free radical integration, de-

chlorination and other processes. To control chloride is an effective way to control the

production of dioxins. Organic chloride in the waste mainly originates from plastics,

leathers, rubbers, etc., among which, the plastic components have a great variety,

usually including polypropylene, polyvinyl chloride, polyethylene, Eps propylene, etc.;

inorganic chloride in the waste mainly originates from kitchen waste.


40

71. Plastic, leather and rubber all belong to recyclable waste and we can not only

achieve wasted resources recycling via waste-sorting, but also effectively control the

pollutants production during the incineration process. Before throwing waste into the

incinerator, pre-sorting technique can be adopted to sort out the transition metals like

copper, iron, nickel, etc. Reduce the quantity of chloride as well as the chloride sources

of dioxins from the beginning to reduce the generation chance and concentration of

dioxins. Chlorine in fly ash comes mainly from waste plastics (mainly PVC plastic),

kitchen waste, waste rubber products, etc. Among them, PVC plastic is dominated by

organic chlorine while kitchen waste is mainly inorganic chloride.

(2) Effect of Moisture Content on Dioxin Production

72. The components of MSW are quite complicated and the moisture content changes

greatly in accordance with the season - summer has larger moisture content while

winter has relatively smaller one. Though pre-treatment before incineration will

somewhat reduce the moisture content of the waste, certain moisture is still inevitably

carried while throwing the waste into the incinerator, which has definite effect on the

combustion and the production of dioxins. During the incineration process, moisture’s

existence will affect the production of dioxins and the distribution of derivatives, forming

a complicated impact on dioxins’ production. On one hand, moisture offers the

hydrogen sources, oxygen sources and sources of hydroxyl radicals that are required

for the reaction of dioxins’ production to promote such production; on the other hand,

moisture competes with organism for the active sites on the reactive surface to change

the balance of Deacon reaction and constrain dioxins’ formation. In actual operation,

the heat and moisture of the waste is perfectly balanced to contribute to the operation’s

stability and reduce dioxins’ production amount.

2.2.8.2 Impact of Waste Classification on Heavy Metals in Fly Ash

73. All kinds of metal wastes contained in the mixed primary waste, such as various

metal products, batteries, and printing paper containing heavy metals, such as Cu, Cr,

Cd, Zn, Hg and so on. In the incineration process, heavy metals will occur migration

and transformation, and can distribute in a variety of ash in the waste incineration

system ultimately. Due to the high temperature in the incinerator, the heavy metals in

the refuse will be released in various forms. Under the presence of Cl2, SO2, O2 and


41

other gases, heavy metals will experience six processes to achieve migration from

primary waste to fly ash: (1) metal evaporation; (2) chemical reactions; (3) particle

entrainment; 4) Condensation of metal vapor and particle coagulation; 5) wall

settlement of steam and particle; 6) particle capture of flue gas purification system. In

the process of heavy metal migration, its own form is also undergoing a series of

complex morphological transformation, among chloride state, oxidation state, sulfide

state, elemental state and other complex forms.

74. The heavy metals in fly ash are mainly from toxic and hazardous waste mixture

such as batteries, pigments, as well as industrial solid wastes.

Table 2-13 Impact of Waste Classification on Heavy Metal Content in Fly

Ash/Bottom Ash mg/kg

Heavy

Metal Classified Waste Mixed Waste

Boiler Dust Bag Filter

Ash Boiler Dust

Bag Filter

Ash

Pb 415 1416 344 1169

Cd 6.4 57 5.70 17

Cu 316 261 189 160

Zn 2665 2274 3053 2084

Cr 212 79 186 70

Ni 70 24 72 40

Mn 1286 251 1047 253

As 73 267 64 222

Hg 0.10 7.70 0.11 4.80

75. Table 2-13 shows that the contents of volatile heavy metals, such as Pb, Cd, Zn,

As and Hg, in the classified and mixed waste incineration fly ash are significantly higher

than those of the bottom ash. While Cu, Cr, Ni and Mn are mainly present in the bottom

ash. Since the bottom ash generated by MSWI is generally regarded as non-hazardous

waste and is widely used in building materials, it is necessary to ensure that its heavy

metal content is sufficiently low to reduce environmental risks. Compared with mixed

waste incineration, whether in the incineration bottom ash or fly ash, the heavy metal

content is lower in classified fly ash, thus indicating the classification of refuse helps to

reduce fly ash and bottom ash in the heavy metal content.


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2.3 Environmental Impact of Fly Ash

2.3.1 Pollution of Soluble Salts

76. Kitchen waste and plastic content usually occupy a relatively high proportion of

about 40%-75% and 20% respectively, leading to a high soluble chlorine salts content

in the fly ash up to 37.3%. It mainly includes the chloride of Ca, Na and K. If improperly

disposed, underground water and natural water will be polluted. At the same time, large

quantity of chloride will increase the solubility of other pollutants - for example, the

solubility of Pb and Zn will increase while the pH value, ionic intensity and chloride

content are all high. In addition, inorganic chlorine salt brings difficulty to fly ash’s

solidification and stability as well as the resources’ utilization process. Consequently,

the harm of chlorine salts in fly ash is never negligible.

2.3.2 Pollution of Heavy Metals

77. Heavy metals are significant pollutants in fly ash. If improperly disposed during its

storing and transporting process, it will be transferred and transformed gradually while

entering to the environment and also pollutes the underground water and air due to its

un-degradability, bringing great harm to the environment rather than damaging the

health of human as well as other animals and plants via the food chains. Fly ash

occupies many heavy metals such as Cu, Pb and Zn, followed by Cr and least Cd

content. Once taken in, they will lead to pathological changes and cancer. When

human take in heavy metals like Pb and Cd via their respiratory and digestive tract,

they will suffer from several diseases. Pb will particularly impact human’s kidney, liver,

nervous system and hematopoietic function due to hard excretion and thus increase

blood pressure, obstruct the kidney function and reproductive function and finally

cause brain injury. The clinical manifestation of chronic poisoning of Cd is pulmonary

emphysema, bone mineralization, anemia and even paralysis.

➢ Burned in high-temperature, heavy metals in fly ash (such as Zn, Pb, Ni, Cd,

etc.) will volatilize into the atmospheric environment and threaten the

environmental safety.


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➢ The leaching concentration of heavy metals like Pb, Zn and Cd in fly ash is

far higher than the standard national limits. If piled-up randomly, the leaching

solution of incineration fly ash will pollute natural water and even do harm to

human health.

➢ Heavy metals such as Pb, Zn, Cr and Cd in fly ash mainly exist in a

combinative form of carbonate state and ferromanganese oxides. Such form

is not stable enough and can easily pollute the environment via the soil or

water.

2.3.3 Pollution of Dioxins

78. Dioxins are the collective name of a group of substances that can be combined

with aryl hydrocarbon receptors and generate various biological and chemical changes.

They belong to persistent organic pollutants. Incomplete waste combustion or low-

temperature hetero-phase catalysis caused by waste composition, ventilation, etc.

during the process of MSW’s incineration will produce organic pollutants such as

dioxins, furans, etc. that are mainly concentrated on fly ash’s particles.

79. The poisonousness of organic pollutants such as dioxins and furans are primarily

manifested in its biotoxicity, which is non-biodegradable and is concentrated on the

food chains, severely threatening the environment and health and having become an

environmental problem and public sanitary problem for general concern worldwide.

Dioxins are poisonous and terribly harmful to human health. They can enter to one’s

body via the skin, respiratory tract and the digestive tract, but 90% of those entering to

human body via the digestive tract are caused by food, especially lipids, being

accumulated in the fat as well as liver and badly affecting human body while it reaches

up to a certain extent. More importantly, the immune function declines, the reproductive

and genetic function change and the malignant tumor becomes much more susceptible.

Even slight ingestion for a long period will cause stubborn diseases such as cancer,

known as the first-grade carcinogen. Besides, dioxins will also cause symptoms like

headache, birth defects, etc. with long-term effect.


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2.3.4 Environmental Impact and Control of Secondary Pollution Caused

by Transportation Littering of Fly Ash

80. There exists potential danger during fly ash’s transportation process, and

discarded fly ash will enter to water and soil on the way, turn to floating dust, and then

float into the air, which will not only increase the dust content in the air, but also

aggravate fog haze’s ecotoxicity, bringing terrible harm to human health as well as the

environment.

81. Article 9 of “Technical Polices on the Prevention and Treatment of Hazardous

Waste” (State Environmental Protection Administration, 2001) in China clearly

stipulates, “MSW’s incineration fly ash must be transported after necessary

solidification and stability treatment in the productive place and the transportation

requires transportation tools for exclusive use as well. Such tools should be airtight as

well.” Fly ash transportation unit must obtain business license for hazardous waste

transportation and strictly conform to the above-mentioned rules during the

transportation process. It should also strengthen its management to avoid secondary

pollution caused by transportation discarding. Meanwhile, improved emergency plans

such as repairing preparing, rescue mechanical equipment and routine drills should be

formulated to control accident risk for any possible discarding accidence.

2.4 Summary

1) With the improvement of urbanization rate and living standards, MSW’s collection

amount increases progressively at an average rate of 4% annually in China.

2) As residents’ requirements toward ecological environment become higher and

higher and their environmental protection consciousness increases gradually, China’s

MSW management becomes much more normative and scientific. Currently, though

the main MSW treatment approach is sanitary landfill, incineration treatment

technology will be proved to be essential techniques for MSW treatment, viewing from

the changes of the number of finished waste treatment constructions and the treatment

scale capability.


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3) As the by-product of MSW’s incineration treatment, the production of fly ash will

increase annually in accordance with the waste incineration amount.

4) Fly ash is listed into hazardous waste in China and its disposal as well as resources

utilization should strictly comply with corresponding regulations and standards.

5) Since the fly ash composition and its properties vary with the change of incinerated

waste components, incineration operation and fuel gas treatment and purification

techniques, harmless treatment or resources utilization technique should therefore be

adopted in term of the fly ash’s components and properties to achieve normative and

economically feasible treatment.


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CHAPTER3 SURVEY AND ANALYSIS OF FLY ASH

FROM TYPICAL INCINERATORS IN PRC

3.1 Selection of Typical Incinerators

82. The incineration treatment technology in China can be classified into three

categories: grate-type technology, fluidized-bed technology and other incineration

technologies (small vertical and chain incinerator, pyrolysis incinerator, etc.). Since

part of small incinerators made in China occupy a small treatment scale and unstable

operation mode, their application is therefore terribly limited with an extremely low

market share. Consequently, the incineration fly ash production or properties of these

kinds don’t have any universalities; however, the property of long-term continuous and

stable operation of grate-type and fluidized-bed incinerators has made them two

mainstream incinerators adopted by MSW’s incineration plants in China, among which, mechanical grate-type incinerator has a much higher market share. Accordingly, this

research on typical incineration plants in China mainly targets at mechanical grate-

type and fluidized-bed incinerators.

83. In addition, MSW’s components, incineration operation of incinerators, fuel gas

treatment and purification system, etc., all directly affect the properties of incineration

fly ash. Thus, as a huge geographical country, MSW’s components in diverse regions in China greatly differ from each other and the fuel gas treatment technology adopted

by MSW incineration plants focuses on dry/semi-dry and wet treatment techniques

while wet treatment technique is relatively rare, only adopted by Laogang MSW

Incineration Plant’s Phase One Operation in Shanghai; by the end of 2015, there had

been 220 incineration plants in operation in China. Due to the limitation of researching

on these 220 incineration plants one by one in detail within the execution period lasting

for 18 months, the choice of typical MSW incineration plants for this fly ash properties

research conforms to the following principles:

1) Choose plants in southern China, eastern coast, central inland and northern

areas from south to north based on regional characteristics;

2) Choose dry/semi-dry and wet treatment techniques based on fuel gas

treatment purification system;

3) Choose mechanical grate-type and fluidized-bed incinerators based on the

incineration types.

84. According to the above principles, a total of 16 typical incineration plants were

selected for this survey, of which 3 were incineration plants of fluidized bed type and 1


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were wet-type incineration plant for flue gas treatment. The others were mechanical

grate furnace with flue gas treatment process of the dry / semi-dry method. List of the

selected plants are as Table 3-1:

Table 3-1 Selected Incineration Plants For Fly Ash Sampling Survey

No. Province City Scale Incineration

Type Flue Gas Purification

System Area

1 Liaoning Dalian 1500t/d Grate Boiler Semi-Dry +Dry +Bag

Filter +Activated Carbon North

2 Hebei Shijiazhuang 1000 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter +Activated Carbon South

3 Tianjin Tianjin 700 t/d Fluidized Bed Semi-Dry +Dry+ Bag

Filter+ Activated Carbon North

4 Tianjin Tianjin 1000 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter +Activated Carbon North

5 Beijing Beijing 1600 t/d Grate Boiler Semi-Dry + Bag Filter+

Activated Carbon +SNCR North

6 Shanghai Shanghai 3000 t/d Grate Boiler Wet Eastern Coast

7 Jiangsu Nanjing 2000 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter +Activated Carbon Eastern Coast

8 Jiangsu Rugao 1500 t/d Fluidized Bed Semi-Dry +Dry +Bag

Filter +Activated Carbon Eastern Coast

9 Zhejiang Ningbo 1500 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter Eastern Coast

10 Zhejiang Hangzhou 1300 t/d Fluidized Bed Semi-Dry +Dry +Bag

Filter

Eastern

Coast

11 Hunan Yiyang 700 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter Inland

12 Sichuan Chengdu 2000 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter Inland

13 Chongqing Chongqing 1200 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter Inland

14 Shenzhen Shenzhen 4200 t/d Grate Boiler Semi-Dry +Dry +Bag

Filter South

15 Guangdong Zhuhai 2000 t/d Grate Boiler Semi-Dry +Dry +Bag


16 Guangdong Foshan 3000 t/d Grate Boiler Semi-Dry +Dry +Bag


3.2 Survey Content

85. Approaches like on-site interview, questionnaire answering and sample analysis

are adopted to conduct field research on the targeted typical MSW landfill plants. The

questionnaire mainly includes the incineration’s basic information, fly ash dioxins

monitoring, heavy metal content of the fly ash, properties of sediments and fly ash, etc.

(Details as per the Attachment 2 Questionnaire)


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3.3 Sampling and Analysis of Fly Ash

3.3.1 Fly Ash Sampling

86. In China, MSW is defined as hazardous wastes and its fly ash sampling should

strictly comply with the standards required by “Identification Standards for Hazardous

Wastes” (HJ/T 298) and “Specifications on Industrial Solid Waste’s Sampling and Sample Preparation” (HJ/T 20). “Sampling & Sample Preparation and Test for

Incineration Sediments from MSW” (2016 Draft for Comment) hasn’t been formally implemented and can therefore act as a reference.

87. Besides, due to the incompetence of China’s MSW treatment, almost all current incineration plants are continuously in operation for 330 days annually with about 3

days as overhaul period every month. Once the overhaul is finished, the incinerators

should be activated at once. Since the activation period is rather short, there will just

produce limited amount of fly ash during this period, accounting for a quite small

proportion of the total fly ash amount. And its properties are not universal. Hence, fly

ash sampling should be conducted during the incineration plants’ continuously stable period and specifications or guidelines based on the treatment technology and

resource utilization of the fly ash’s universality research could be much more widely applicable with the significance of worldwide promotion and application.

88. During the incineration plants’ actual operation process, one-time fly ash test

requires at least 24-hour fly ash amount from incinerators as a batch. Then, choose

the smallest sample based on the batch, among which, heavy metal should be tested

at least once a month while dioxins tested once or twice a year. Every time, the

sampling must choose at least 8 samples and it should also be conducted once an

hour with 1kg as each sample’s quantity. Once the sampling is less than 1kg, it can be divided into several times until the final sample quantity is reached. Besides, these

samples should be selected from diverse periods as much as possible to ensure the

representativeness.

89. Suitable sampling approaches should be chosen under the strict sampling

standards and based on the specific waste incineration plants’ actual techniques. The following works should be guaranteed:

❖ Before the on-site fly ash sampling, operators should protect themselves

perfectly. For example, they should wear the protective equipment such as

safety helmets, masks and gloves to ensure the sampling operators’ safety in one hand and keep the incineration plants’ regular operation in the other.

❖ The preferred sampling location is the inner part of the blending device. Other

locations such as the fly ash hopper can also be selected as the sampling


49

point if convenient. One thing needed to be ensured is that the sampling

sample is original fly ash.

❖ While sampling, materials in the blending device should be evacuated at first.

After pouring fly ash from fly ash hoppers or other fly ash measuring devices

into the blending device and before adding stabilizer, hardener, moisture and

other materials, the incineration plant’s device operator should stop the blending device’s operation and then, the sampling personnel could open the

sampling door of the device. After that, he can collect samples with a sampler

from the place where samples are piled up and avoid side and skin materials.

Take out the sampler after the collection and put it into the prepared sample

bag, sealed for conservation. Till now, the sampling will be completed. Clear

possible material deposit from the sampler to get prepared for the next

sampling. Mark the sample with its origins, sampling time, sample properties

(raw fly ash) and number. Conduct the following sampling activity according

to the time requirement.

3.3.2 Test Methods

90. Detection of heavy metals (Pb Cd Cu Zn Ni As Cr Mn): solid waste or solid

waste leachate after acid digestion, into the plasma emission spectrometer nebulizer

atomized by argon carrier gas into the plasma torch, the target Elements are gasified

in a plasma torch, ionized, excited and radiated out of the characteristic line. The

intensity of the characteristic spectrum is proportional to the amount of the element to

be measured in the sample within a certain range. Test will be conducted according to

standard methods in HJ781-2016 Solid Waste–Determination of 22 Metal Elements–Inductively Coupled Plasma Optical Emission Spectrometry.

91. Detection of mercury: Solid waste and leachate sample after microwave

digestion, enter the atomic fluorescence spectrometer, in which the mercury element

in the potassium borohydride solution to reduce the role of mercury vapor generated.

The gas forms a ground state atom in the argon-hydrogen flame and generates atomic

fluorescence upon excitation of the elemental light (mercury) emission. The atomic

fluorescence intensity is proportional to the elemental content in the sample. Test will

be conducted according to standard methods in HJ702-2014 Solid waste–Determination of Mercury, Arsenic, Selenium, Bismuth, Antimony— Microwave

Dissolution / Atomic Fluorescence spectrometry.

92. Dioxins test: The sample is extracted, purified and solvent exchanged into the

EIA tube. The PCDD/Fs in the sample bind specifically to the PCDD/Fs antibody on

the inner surface of the tube. The PCDD/Fs antibody in the EIA tube is in excess and

the remaining unbound PCDD/Fs antibody binds to the addition of a competitive

enzyme label. The amount of PCDD/Fs antibody in each EIA tube is constant and the


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amount of PCDD/Fs in the sample can be calculated by measuring the amount of

enzyme label bound to the PCDD/Fs antibody. This standard using TEQ value to

characterize the amount of PCDD/Fs of the sample. Test is conducted with reference

of DB12/T 403-2008 Solid waste - Determination of dioxins - Enzyme immunoassay.

3.4 Results and Analysis

3.4.1 Fly Ash Sample Numbering

93. The fly ash sample shall be numbered as follows based on different areas of

municipal solid waste incineration plant, incinerator types and treatment processes:

94. For example, NGD-DL means the fly ash is from the municipal solid waste

incineration plant located in Dalian City in northern China and the plant adopts

mechanical grate boiler and dry method /semi-dry method for flue gas treatment.

3.4.2 Result Analysis

3.4.2.1 All Survey Results

95. At present, the testing and analysis of 16 samples are completed with the testing

and analysis results shown in Table 3-2. According to Table 3-2, the data of such 16

samples has obvious data jumpiness and contingency without significant regularity,

because fly ash characteristic is influenced by many factors, such as solid waste

contents, actual incineration operating conditions and flue gas treatment process.

Despite the data jumpiness, the order of magnitudes shows that total content of heavy

metals and dioxin toxic equivalent of most samples are at the same order and the

contents of all heavy metal elements are less than 2%, which are basically the same

as the research statistic values. It can be seen from this that the contents of Zn in f ly

ash in China is the highest, followed by Pb, Cu and Mn, the concentrations of other

heavy metal elements are relatively low and dioxin toxic equivalent fundamentally

remains at 30-70 pg TEQ/g.

* * * * * -- - Acronym of city name

flue gas treatment process: D-dry method/semi-dry method W-wet method.

Incinerator type: G- grate furnace, F- fluidized bed

Facility location: N- Northern China (northeast China and north China) E- Eastern coast of china (Shanghai, Zhejiang and Jiangsu) S- Southern China (Shenzhen and Guangdong) M- Middle of China (Hunan, Sichuan and Chongqing)


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Table 3-2 Analysis Results of Total Content of Heavy Metals and Dioxin Equivalent in Fly Ash Samples from Typical Incineration Plants

Sample number

Total content of heavy metals, mg/Kg Dioxin toxic equivalent

(pg TEQ/g) Pb Cd Cu Zn Ni As Cr Hg Mn

NGD-

DL 1773 182 487 12565 23.9 30.6 536 10.8 253 38

NGD-

SJZ 1456 189 571 2791 10.7 26 40.8 8.3 120 67

NFD-TJ 488 37 377 3256 33.9 18.7 122 4.2 573 52

NGD-TJ 881 80.4 443 4241 204 36.5 226 10.2 776 54

NGD-BJ 1040 74.8 256 3487 28.9 24.8 123 5.5 332 13

EGD-NJ 1296 115 507 4660 38.5 28.3 166 6.7 263 48

EFD-

RG 731 20.2 861 3452 114 11.9 359 3.6 619 58

EGD-

NB 1254 108 539 4416 40.6 54.6 129 6.6 191 46

EGW-

SH 3605 23.5 975 11531 0 47.0 117 9.3 183 79

EFD-HZ 687 29.7 437 3219 48.3 29.7 198 1.9 586 49

MGD-

HN 107 13.1 69 888 19.6 21.3 82.4 0.8 166 3.5

MGD-

CQ 2119 163 685 6318 31.7 50.3 202 2.5 315 65

MGD-

CD 1146 94.8 605 4968 73.5 39.3 195 2.1 209 58

SGD-SZ 1540 134 1552 8197 59.8 31.7 151 8.6 234 36

SGD-

ZH 976 50.1 842 4539 108 24.3 319 4.8 326 44

SGD-FS 1244 62.0 688 5786 243 28.2 1562 15.5 800 32

3.4.2.2 Impact of Different Areas on Total Content of Heavy Metals and Dioxin Toxic Equivalent in Fly Ash

96. Figure 3-1 shows the change in total content of heavy metals in incineration fly

ash from mechanical grate boilers adopting the same flue gas treatment process in

different areas. According to Figure 3-1, the highest total Zn content in incineration

fly ash from mechanical grate boilers of all incineration plants surveyed is 12,565mg/kg,

followed by Pb and Cu. The Zn content in fly ash from eight different urban areas

surveyed changes significantly, so do other heavy metal contents. The solid waste

components are different in various areas because of different economic levels and

living habits of residents, and thus the properties of fly ash compositions change

significantly after municipal solid waste incineration.


52

Figure 3-1 Total Content of Heavy Metals in Incineration Fly Ash from

Mechanical Grate Furnace In Different Areas

Figure 3-2 Dioxin Toxic Equivalent in Incineration Fly Ash from the Same

Type of Incinerators in Different Areas

97. Similarly, Figure 3-2 shows dioxin toxic equivalent in incineration fly ash from the

same type of incinerators in different regions. According to Figure 3-2, the order of

magnitudes of dioxin toxic equivalent in the incineration plants in Hunan area in the

middle of China is relatively stable and remains in the range of 30-70, except for that

of an incineration plant (MGD-HN). Therefore, the location of municipal solid waste

incineration facilities has some impact on the dioxin toxic equivalent, but the impact is

not significant.

3.4.2.3 Impact of Different Types of Incinerators on Total Contents of Heavy Metals and Dioxin Toxic Equivalent in Incineration Fly Ash

98. Figure 3-3, 3-4 and 3-5 show the total content of heavy metals in incineration fly

0102030405060708090

二噁英毒性当值 pg TEQ/gDioxin Toxic Equivalent (pg TEQ/g)


53

ash from mechanical grate boiler and fluidized bed in Tianjin area and Jiangsu area

respectively. According to Figure 3-3, 3-4 and 3-5, the total content of heavy metals in

incineration fly ash from mechanical grate boiler is higher than that from fluidized bed,

which is basically the same as the statistical result of previous research, but the

difference between them is not higher than the statistical result of previous research.

The statistical results show that the content of heavy metal in incineration fly ash from

mechanical grate boiler is higher than that from fluidized bed, by the maximum of over

10 times and the average of 7 times with regard to Zn content, the maximum of 7 times

and the average of 3 times with regard to Cu, the average of 7, 4, 4, 1.5 and 0.3 times

with regard to Cd, Pb, Cr, Ni, and Hg. It indicates that the difference between total

contents of heavy metals in incineration fly ash from mechanical grate boiler and

fluidized bed is becoming smaller and smaller after the standard and meticulous

management is conducted the operation of for municipal solid waste incinerator,

accounting for the increasingly high environmental protection effect.


Mechanical Grate Boilers and Fluidized Beds in Tianjin Area


Mechanical Grate Boilers and Fluidized Beds in Jiangsu Area

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Pb Cd Cu Zn Ni As Cr Hg Mn

NFD-TJ

NGD-TJ

0

1000

2000

3000

4000

5000


EGD-NJ

EFD-RG


54

Figure 3-5 Total Content of Heavy Metals in Incineration Fly Ash from Mechanical Grate Boilers and Fluidized Beds in Zhejiang Area

Figure 3-6 Dioxin Toxic Equivalent in Incineration Fly Ash from Mechanical Grate Boiler and Fluidized Bed in the Same Area

99. Figure 3-6 shows the dioxin toxic equivalent in incineration fly ash from mechanical

grate boiler and fluidized bed in Tianjin area and Jiangsu area respectively. According

to Figure3-6, the difference between dioxin toxic equivalents in incineration fly ash from

mechanical grate boiler and fluidized bed is not large. Under standard management

conditions, the dioxin toxic equivalent in fly ash may not be used as the reference for

incinerator type selection.

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000


EGD-NB

EFD-HZ

0

10

20

30

40

50

60

70

NFD-TJ NGD-TJ EGD-NJ EFD-RG EGD-NB EFD-HZ



55

3.4.2.4 Impact of Different Flue Gas Treatment Processes on Total Content of Heavy Metals and Dioxin Toxic Equivalent in Fly Ash


Heavy Metals in Fly Ash


Heavy Metals and Dioxin Toxic Equivalent in Fly Ash

100. From Figure 3-7, it can be seen that under the same raw material and

incinerator type, wet gas treatment process is more efficient in collecting most heavy

metals in flue gas, especially for the Pb, Cu and Zn with content of 3605mg/kg, 975

mg/kg and11531 mg/kg, respectively, all of them are over 2 times more than dry

method. Meanwhile, as is shown in Figure 3-8, wet method also captures more dioxins

than dry method, with wet method captured 79 pg TEQ/g dioxins whereas dry method

0

2000

4000

6000

8000

10000

12000

14000


EGW-SH

EGD-NJ

EGD-NB

0

10

20

30

40

50

60

70

80

90

EGW-SH EGD-NJ EGD-NB



56

only 47 pg TEQ/g.

101. Above all, wet flue gas treatment method is more efficient in the capture of

heavy metals and dioxins in flue gas. But wet method requires large consumption of

water and the process is severely corrosive for equipment and the generated waste

solid and liquid are hard to dispose, causing secondary pollution. As a result wet

method is still not applied widely.

3.4.2.5 Description of Dioxins Toxicity Determination Methods

102. At present, the most widely used method to detect dioxins is chromatography,

especially high-resolution gas chromatography combined with high-resolution mass

spectrometry (HRGC/HRMS). This method requires complex sample preparation

processes, long test cycles, sophisticated instrumentation, a good experimental

environment, professionally trained operators, and qualitative and quantitative

standards. The detection method of dioxins costs as much as $ 1,000, and for the

detection of dioxins produced during incineration, their sampling methods can not fully

reflect the generation of dioxins.

103. Dioxins have high affinity to Ah receptors of organisms and can specifically

induce cytochrome P450 enzymes, which can be determined by EROD enzyme

activity. The method has a linear dose-response relationship within a certain

concentration range and can be used for the determination of dioxins in samples. At

present, Enzyme Immuno Assay (EIA) is mainly used in the field both at home and

abroad, and the immunization kit has been sold. The cost for testing each sample is

$60-80. EIA method has the characteristics of short analysis period and low analysis

cost, and the detection limit of the sample can reach the level of pg/g or ng/L. Therefore,

EIA can be used as a rapid screening method for a large number of samples and is

particularly suitable for carrying out large-scale dioxin background investigations.

Dioxins in this project using enzyme immunoassay for biological testing. The principle

and method of testing can refer to the literature (Li Wen, et al. Rapid quantitative

screening of dioxin contaminants in environmental samples using the EIA bioassay

method. Environmental science, 2000,21(4): 70-73).

(1) The Standard Curve, Detection Limit and Linearity Detection Range of EIA

Detection Method

104. A series of standard working solutions of 0, 3.2, 10, 32 and 100 pg • tube - 1

were prepared from methanol with 2,3,7,8 – TCDD, and analyzed absorbance

values(OD) by EIA separately, and then a dose-response standard curve for 2,3,7,8-

TCDD was made. As shown in Figure 3-9, the standard curve is inverted "S" with

equation: y = (64.4 / (1 + (x /12.5) 1.89)) + 34.1 ,and R2 is 0.996. The half-effect dose

I50 was 22.5pg • tube-1.


57

105. According to the provision of US EPA for the Laboratory Detection Limit (MDL),

Six consecutive spiked samples close to the limit of detection were analyzed

consecutively to a standard deviation (S) of 1.1 pg • tube-1 (ie 1.1 pg TEQ per EIA

tubes), and then determined the lower limit of detection with 3-fold standard deviation

of 3.3 pg • tube-1, lower limit value of quantitation with a 10-fold standard deviation of

11 pg • tube-1.

Figure 3-9 3 2,3,7,8-TCDD Toxicity Response Value (pg • tube-1)

106. As can be seen from Figure 3-9, the best linear correlation of the standard

curve is between 3.2 pg • tube-1 and 32 pg • tube-1 with a linear equation of y = -0.581x

+ 55.81 and R2 of 0.962. Considering the lower limit value of quantitative is 11 pg • tube-1, the concentration of the test sample (converted to 2,3,7,8-TCDD toxicity

response by EIA) should be in the range of 10-30 pg • tube-1,with larger deviation

beyond this range.

(2) Mathematical Correlation between EIA Analysis Results and HRGC/HRMS

Analysis Results

107. In order to correct the system error, a standard solution of fly ash was

prepared. The standard solution was formulated into a series of standard working

solutions. The standard curve of dose-effect relationship of PCDD / F was plotted and

the two types of fly ash sample and two samples of flue gas was analyzed quantitatively

based on the curve, the results shown in Figure 3-10. The preparation method of the

fly ash standard solution is as follows: a certain amount of fly ash is subjected to

Soxhlet extraction, and the extract is distilled to 2 to 3 mL to give a volumetric capacity.


58

A portion is subjected to HRGC / HRMS quantitative analysis, and the remaining

solution is passed through a silica gel column connected to a small carbon Column

purification treatment, the test solution as a standard solution of fly ash, TEQ value

(calculated by the HRGC / HRMS analysis) of the fly ash extract after constant volume

as the TEQ value of the fly ash standard solution.

108. As can be seen from Figure 3-10, the standard curve equation for the dose-

response relationship of PCDD / F is: y = (72.0 / (1 + (x / 50.9) 1.49)) +27.2 and R2 is

0.982. The HRGC / HRMS values (measured values) of the TEQ concentrations of the

two samples were 110.3pg • Nm-3 and 123.5pg • Nm-3, respectively, with predicted

values of 98.7pg • Nm-3 and 108.6pg • Nm-3. The HRGC / HRMS values (measured

values) of TEQ concentrations in the two fly ash samples were 1556.0 ng • kg -1 and

3420.3 ng • kg-1, respectively, with the predicted values of 1489.2 ng • kg-1 and 3213.7

ng • kg-1. The relative deviations (Rd) of the HRQC / HRMS values (measured values)

and the predicted values of the curves of the TEQ concentrations of the four analysis

samples ranged from 4.5% to 13.7%, less than 15%, which makes it feasible to

determine the TEQ value of unknown fly ash and flue gas with the purified f ly ash

solution as a standard solution. The root cause of this feasibility is that the distribution

patterns of PCDD / F in all waste incineration fly ash and flue gas are about the same.

Figure 3-10 PCDD/F Toxicity Response Value (pg • tube-1)

109. The main reason why the existence of certain differences between EIA test

and HRGC/HRMS analysis is the EIA system error.


59

1) The recovery of PCDD/F passing through-column purification treatment in fly ash

samples was about 50%, making the TEQ value measured by the EIA method

lower than half the real value.

2) The loss of TCDD/F during the process of passing through-column purification

treatment was big, especially 2,3,7,8 - TCDD/F, which decreased the response of EIA.

3) The presence of other impurities interferes with the cross-reaction of PCDD/F with

the enzyme.

4) EIA method for total 2,3,7,8-TCDD toxicity response range of 10 - 30 pg • tube-1,

beyond this range, the test results may be a large deviation.

3.4.2.6 Relationship between Heavy Metal and Dioxin Content in Fly Ash and Domestic Waste

110. Municipal solid waste components and heavy metal content and dioxin

toxicity equivalent of incineration fly ash in the northern typical area in Table 3-3 and

Table 3-4, respectively.

Table 3-3 Municipal Solid Waste Components in the Northern Typical Area

Component%

Beijing Dalian Tianjin Average

Food 56.1 73.39 63.22 64.2

Paper 11.76 3.37 11.74 9.0

Glass 3.84 2.56 - 3.2

Metal 1.69 0.51 - 1.1

Plastic 12.6 5.66 14.63 11.0

Fabric 2.75 1.63 - 2.2

Inorganic 8.32 4.14 3.89 5.5

Table 3-4 Heavy Metal Content and Dioxin Toxicity Equivalent of Incineration

Fly Ash in the Northern Typical Area

Sample Heavy Metal Total Amount (mg/kg) Dioxin Toxicity

Equivalent Value

No. Pb Cd Cu Zn Ni As Cr Hg Mn pg TEQ/g

NGD-DL

1773 182 487 12565 23.9 30.6 536 10.8 253 38

NFD-TJ 488 37 377 3256 33.9 18.7 122 4.2 573 52 NGD-TJ 881 80.4 443 4241 204 36.5 226 10.2 776 54 NGD-BJ 1040 74.8 256 3487 28.9 24.8 123 5.5 332 13 Average 1046 94 391 5887 73 28 252 8 484 39

111. As can be seen from Table 3-3, the food components of domestic solid

waste in the northern cities are the highest, followed by plastic, paper and inorganic

materials. The food proportion of domestic solid waste in Dalian was highest,


60

accounting for 73.39%. Cities with high paper and plastic components are Beijing and

Tianjin. The higher the metal content is Beijing, accounting for 1.69%. As can be seen

from Table 3-4, the order of heavy metal content in fly ash from typical northern cities

is Zn> Pb> Mn> Cu> Cr> Cd> Ni> As> Hg. The contents of Pb and Zn were the highest

in fly ash in Dalian, Hg in fly ash in Tianjin and Dalian, and the contents of Cr and Cu

in fly ash in Dalian were the highest. The sequence of toxic equivalent of dioxins was

Tianjin> Dalian> Beijing. The high content of Pb, Zn and Hg in Tianjin fly ash may be

related to the large amount of seafood residues contained in the food components of

the domestic solid waste component, while the shellfish residue contains Pb and Zn,

and the fish residue contains Hg .


toxicity equivalent of incineration fly ash in the eastern typical area in Table 3-5 and


Table 3-5 Municipal Solid Waste Components in the Eastern Typical Area

Component (%) Shanghai Nanjing Hangzhou Ningbo Average

Food 58.55 47.3 60.5 50.63 54.245

Paper 6.68 12.63 7.18 20.92 11.8525

Glass 4.05 0.84 1.94 3.86 2.6725

Metal 2 0.41 0.81 1.47 1.1725

Plastic 11.84 20.38 14.52 15.7 15.61

Fabric 2.26 4.09 2.01 3.63 2.9975

Inorganic 7.54 4.93 10.52 1.24 6.0575


Fly Ash in the Eastern Typical Area


Equivalent Value


EGD-NJ 1296 115 507 4660 38.5 28.3 166 6.7 263 48

EGD-NB

1254 108 539 4416 40.6 54.6 129 6.6 191 46

EGW-SH

3605 23.5 975 11531 0 47 117 9.3 183 79

EFD-HZ 687 29.7 437 3219 48.3 29.7 198 1.9 586 49

Average 1711 69 615 5957 32 40 153 6 306 56

113. As can be seen from Table 3-5, the food components of domestic solid waste

in the eastern cities are the highest, followed by plastic and paper. The food proportion

of domestic solid waste in Hangzhou was highest, accounting for 60.5%. Cities with

high plastic components is Nanjing, and high paper is Ningbo. The higher the metal

content is Shanghai, accounting for 2%. As can be seen from Table 3-6, the order of

heavy metal content in fly ash from typical eastern cities is Zn> Pb> Cu> Mn> Cr> Cd>


61

As> Ni> Hg. The contents of Pb and Zn were the highest in fly ash in Shanghai, and

Hg and Cu contents are relatively high as well. The sequence of toxic equivalent of

dioxins was shanghai> Nanjing≈ Hangzhou≈ Ningbo. The high content of Pb and Zn

in Shanghai fly ash may be related to metal components of domestic waste, Hg related

to the large amount of seafood residues contained in the food components of the

domestic solid waste component, while the shellfish residue contains Pb and Zn, and

the fish residue contains Hg. The relatively high content of As in fly ash in Ningbo may

be related to the high content of paper components in household waste in Ningbo.


toxicity equivalent of incineration fly ash in the middle typical area in Table 3-7 and


Table 3-7 Municipal Solid Waste Components in the Middle Typical Area

Component (%) Chongqing Chengdu average

Food 57.65 61.05 59.35

Paper 12.36 15.34 13.85

Glass 3.54 - 3.54

Metal 1.77 0.1 0.935

Plastic 11.59 10.8 11.195

Fabric 4.83 1.1 2.965

Inorganic 4.17 10.65 7.41

115. Table 3-8 Heavy Metal Content and Dioxin Toxicity Equivalent of

Incineration Fly Ash in the Middle Typical Area


Equivalent Value


MGD-CQ

2119 163 685 6318 31.7 50.3 202 2.5 315 65

MGD-CD

1146 94.8 605 4968 73.5 39.3 195 2.1 209 58

Average 1633 129 645 5643 53 45 199 2 262 62


in the eastern cities are the highest, followed by plastic and paper. The food proportion

of domestic solid waste in Chengdu was highest. Cities with high plastic components

is Chongqing, and high paper is Chengdu. The higher the metal content is Chongqing,

accounting for 1.77%. As can be seen from Table 3-8, the order of heavy metal content

in fly ash from typical eastern cities is Zn> Pb> Cu> Mn> Cr> Cd > Ni> As > Hg. The

contents of Pb and Zn were the highest in fly ash in Chongqing, and the contents of

Cu, Cr and Hg in fly ash of two cities in the central region are similar. The sequence of

toxic equivalent of dioxins was Chongqing> Chengdu. The high content of Pb and Zn

in Chongqing fly ash may be related to plastic components of domestic waste, which


62

may lead to higher dioxin toxicity equivalent


toxicity equivalent of incineration fly ash in the southern typical area in Table 3-9 and


Table 3-9 Municipal Solid Waste Components in the Southern Typical Area

Component (%) Shenzhen Foshan Zhuhai Average

Food 44.1 52.64 66.9 54.55

Paper 15.34 11.29 - 13.32

Glass 2.53 2.92 - 2.73

Metal 0.47 1.26 - 0.87

Plastic 21.72 15.13 11.3 16.05

Fabric 7.4 9.75 3.7 6.95

Inorganic 1.99 6.05 2.8 3.61


Fly Ash in the Southern Typical Area

Sample Heavy Metal Total Amount (mg/kg)

Dioxin Toxicity

Equivalent Value


SGD-SZ

1540 134 1552 8197 59.8 31.7 151 8.6 234 36

SGD-ZH

976 50.1 842 4539 108 24.3 319 4.8 326 44

SGD-FS

1244 62 688 5786 243 28.2 1562 15.5 800 32

Average 1253 82 1027 6174 137 28 677 10 453 37


in the southern cities are the highest, followed by plastic and paper. The food

proportion of domestic solid waste in Zhuhai was highest, accounting for 66.9%. Cities

with high plastic and paper components is Shenzhen. The higher the metal content is

Zhuhai, and Foshan with high fabric proportion. As can be seen from Table 3-10, the

order of heavy metal content in fly ash from typical eastern cities is Zn> Pb> Cu> Mn>

Cr> Ni > Cd > As > Hg. The contents of Pb, Zn and Cu were the highest in fly ash in

Shenzhen, with relatively high contents of Cd and Cu. The high content of Pb and Zn

in Shenzhen fly ash may be related to plastic components of domestic waste, and the

high content of Cr and Mn in Foshan may be related to the large amount of fabric

materials. The sequence of toxic equivalent of dioxins was Zhuhai> Shenzhen≈

Foshan.

119. The content of heavy metals in fly ash and the content of metals in domestic

waste show a certain correlation.


63

120. (1) From the perspective of City

121. The proportion of metal components in domestic waste components in

Shanghai is 2.0%, which is the highest content in domestic urban research. Compared

with the corresponding heavy metal of fly ash in other cities, the content of Pb in fly

ash is the highest (3605 mg/kg), and the sum of the content of Pb and Zn is also the

highest (15136 mg/kg). Chongqing is the city with the second highest metal content in

municipal solid waste, accounting for 1.77% of its metal content, and its Pb content in

fly ash is 2119 mg/kg, ranking the second in terms of Pb content in fly ash in the

research cities. It is also found that dioxin levels in Shanghai and Chongqing fly ash

samples are also the top two cities in the survey, 79 pg TEQ/g and 65 pg TEQ/g,

respectively. The high dioxin content may be directly related to the higher metal content

of domestic waste. Metal chlorides (PbCl2, ZnCl2) have a strong catalytic effect on

dioxin generation. However, the proportion of metal components in domestic waste

components in Beijing was 1.69%, ranking the third in the research cities. The content

of Pb and Zn in fly ash was 1040 mg/kg and 3487 mg/kg respectively, and the dioxin

content was 13 pg TEQ/g, all located in the middle and lower reaches of the surveyed

cities, which may be related to the strict standard of flue gas emission in Beijing.

122. The content of food components in domestic solid waste in Dalian accounted

for 73.39%, probably due to the fact that the solid waste components contained many

residues of seafood such as shellfish, crabs and fish-bone residue, etc. Different

seafood residues may be enriched in different heavy metals. For example, shellfish

seafood residues are enriched in heavy metals Pb and Cd, while fish seafood residues

are enriched in Hg elements. Therefore, the contents of Hg, Pb and Cd in fly ash of

Dalian are both in the upstream of the investigated cities. Similarly, we also found that

the content of Hg in fly ash in Tianjin area is high (10.2 mg/kg), which may be closely

related to the consumption of seafood fish by Tianjin residents. The content of Hg in

inland cities such as Beijing, Nanjing, Ningbo and Chongqing are relatively low, which

may link to the low proportion of seafood in diet of local residents.

123. Foshan region gathers a large number of textile printing and dyeing

enterprises, so the local domestic waste in a high proportion of textile components,

accounting for 9.75%. Cr and Mn are commonly used oxidants and stains in textile

printing and dyeing industrial, therefore, the Cr and Mn content in Foshan fly ash is the

highest proportion in the investigated cities, with contents of 1562 mg/kg and 800

mg/kg, respectively.

124. (2) From the perspective of Waste Components

125. Plastic production process needs to add a variety of additives, such as

plasticizers, stabilizers, fillers, colorants, antioxidants, etc., which contain a variety of

heavy metals, such as stabilizers containing lead salt, zinc salt, cadmium salt, etc. ,

Colorants contain chromium salts, cadmium salts, etc. Therefore, the content of Pb,


64

Zn and Cd in fly ash from cities such as Shenzhen, Nanjing and Hangzhou where the

plastic components are higher in MSW are slightly higher than those in other cities city.

126. The proportion of paper components in municipal solid waste in economically

developed cities, such as Beijing, Nanjing, Ningbo and Shenzhen, is relatively high,

and the heavy metals contained in the paper mainly include As, Hg, Pb, Cr, Cd and Ni

etc., resulting in the high content of these heavy metals in urban fly ash, especially As

content. For example, the proportion of paper components in domestic waste of Ningbo

is 20.92%, which is the highest in the investigated cities. The content in fly ash is also

the highest, with As content being 54.6% mg/kg, which can conclude that the content

of As may come mainly from paper components in domestic waste.

127. The proportion of food components in domestic waste components is high in

all cities. The content of heavy metals contained in kitchen waste is very low (the

contents of Pb, Cr, Cd and As are usually lower than 10 mg/kg). However, kitchen

waste components containing large amounts of plastic, waste paper, metal, fabric, etc.,

are as complex as domestic waste components, which are important sources of fly ash

heavy metal.

128. It is important to point out that Cd is a volatile heavy metal that enters the fly

ash through a volatilization-condensation-adsorption process. Fluidized bed

incinerators escape large amounts of particulate matter that are subsequently captured

as fly ash, diluting the Cd in fly ash. Therefore, the content of Cd in the fluidized bed

fly ash is significantly lower than the grate boiler fly ash. The content of Cd in fly ash is

basically unaffected by the flue gas purification process, and there is no obvious

difference in the fly ash of different flue gas purification systems.

129. In general, the concentration of Zn and Pb in fly ash exceeded that of Cu, Cr,

Cd and Ni by more than one order of magnitude, and the total concentration decreased

continuously according to Zn> Pb> Cu> Cr> Ni> Cd. In our country, MSW is often

mixed with many harmful heavy metal wastes (such as batteries, discarded small

household appliances, etc.) without proper sorted and sorted treatment. At the same

time, MSW contains a large amount of food waste and plastic, ZnCl2 and PbCl2 and

other metal chlorides easily formed in the incineration process, these heavy metal

chlorides with low boiling point, highly volatile to the flue gas and finally adsorbed on

the fly ash particles, and then captured by the air pollution control device, which led to

a large number Zn and Pb in fly ash.

130. Dioxins in fly ash in most cities in China are generally below the emission

factor set by UNEP (15 μgTEQ/t). Fly ash from a fluidized bed incinerator has higher dioxin toxicity than fly ash from a grate furnace, possibly due to the fluidized bed

incineration temperature and the incomplete loading of the incinerator. Dioxins in fly

ash are largely de novo reaction pathways. Large amounts of PCDD/Fs are formed in

the stack due to the abundant gaseous HCl, volatile organic compounds, PCDD/Fs


65

precursors. The formation of dioxins, both precursors and de novo syntheses, needs

to be catalyzed by heavy metal chemicals such as inorganic chlorides (NaCl, KCl),

heavy metal chlorides and oxides (such as ZnCl2, PbCl2, ZnO, etc.) which is the

decisive factor of organic pollutants in fly ash. It is the enrichment of these heavy metal

chlorides, oxides and inorganic chlorides in fine particles that explain the dioxin

enrichment mechanism in fine particles. Therefore, the high content of food

components, plastic components and metal components of domestic waste

components, the high content of dioxin in fly ash, for example, Shanghai, Hangzhou,

Chongqing, Shijiazhuang and other cities.

3.5 Summary

131. In the project, 17 typical incineration plants were selected for site survey and

sampling analysis. The result analysis shows that:

1 The data of such 10 samples has obvious data jumpiness and contingency

without significant regularity, because fly ash characteristic is influenced by many

factors, such as solid waste contents, actual incineration operating conditions and flue

gas treatment process.

2 The order of magnitudes shows that total content of heavy metals and

dioxin toxic equivalent of most samples are at the same order and the contents of all

heavy metal elements are less than 2%, which are basically the same as the research

statistic values.

3 The contents of Zn in fly ash in China is the highest, followed by Pb, Cu

and Mn, the concentrations of other heavy metal elements are relatively low and dioxin

toxic equivalent fundamentally remains at 30-70 pg TEQ/g.

4 The total content of heavy metals in incineration fly ash from mechanical

grate boiler is higher than that from fluidized bed, which is basically the same as the

statistical result of previous research, but the difference between them is not higher

than the statistical result of previous research.

5 The difference between dioxin toxic equivalents in incineration fly ash from

mechanical grate boiler and fluidized bed is not large.

6 Compared with dry method, wet flue gas treatment method is more efficient

in the capture of heavy metals and dioxins in flue gas.

7 There is a certain difference between the EIA in the determination of


66

dioxins in fly ash and the HRGC / HRMS analysis. The main reason may come from

the systematic error of EIA.

8 The main reason for the high proportion of Zn and Pb in fly ash is that solid

waste is often mixed with waste containing heavy metal materials (batteries,

abandoned small appliances, etc.). The formation of dioxins requires that the

interaction of heavy metal chlorides and oxides (such as ZnCl2, PbCl2, ZnO, etc.) under

the catalysis of heavy metal chemicals is the decisive factor of organic pollutants in the

fly ash. It is the enrichment of these heavy metal chlorides in fine particles that explain

the dioxin enrichment mechanism in fine particles.

TA-8963 PRC Draft Final Report Chapter IV

67

CHAPTER4 TECHNOLOGIES FOR REUSE,

TREATMENT AND DISPOSAL OF MSW INCINERATION

FLY ASH

132. Since fly ash occupies the instability and component-uncertainty of pollutants,

especial when it gathers heavy metals from incineration fuel gas, dioxins and other

volatile materials, fly ash is therefore managed as hazardous wastes in all countries of

the world. Its treatment and disposal should be secure and harmless. For example,

MSW’s incineration fly ash is clearly listed into “National Catalogue of Hazardous

Wastes” as hazardous waste with the list number of HW18. Its disposal should strictly

conform to the regulated standards of Article 9 of “Technical Polices on the Prevention

and Treatment of Hazardous Waste” (State Environmental Protection Administration,

2001). Whether the landfill disposal or resource utilization technology is selected, the

corresponding leach toxicity requirements should be satisfied via the safety pre-

treatment. Likewise, the solid wastes management regulation – “The Waste Disposal

and Public Cleansing Law” in Japan has also specified that fly ash must be treated

with the following four processes before entering into landfill plants or conducting

resource utilization: melting and solidification, cement solidification, chemical

stabilization and acidic leaching.

133. Currently, innocent treatment technology developed for the treatment of fly

ash mainly includes three categories – solidification and stabilization, wet chemical

treatment as well as high-temperature treatment. Solidification and stabilization mainly

contains cement solidification, chelator stabilization, compressing solidification, etc.;

wet chemical treatment is comprised of two types including acid extraction and

neutralizing carbonation with fuel gas while high-temperature treatment mainly

includes sintering solidification and melting vitrification. Likewise, filled by heavy metals

or rare metals, together with its personal physicochemical properties, fly ash still has

certain properties of resource utilization. Selecting proper technology, completing

safety management, and satisfying economic requirements, both final treatment and

disposal or resource utilization will turn to be suitable technology for fly ash

management.


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4.1 Fly Ash Treatment and Disposal Technologies and Reuse

Methods

4.1.1 Fly Ash Treatment and Disposal Technologies

4.1.1.1 Cement Solidification – Landfill Technology for Hazardous Wastes

134. Cement solidification adds Portland cement into incineration fly ash to form

high-strength lumps similar to rocks and hydroxyl with high basicity from the cement

can transfer heavy metals into materials with low solubility such as hydroxide so as to

intercept heavy metals. The primary principle can be concluded as pozzolanic reaction

and hydration. Hydrate gel like calcium silicate and calcium aluminate generated by

reaction will finally form into crystalline state over time and then cover the heavy metals

ions to form a stable structure and reach the ultimate strength of the solidifying object

at the same time.

135. Though cement solidification is relatively low-cost and the technique system

is mature as well as easy to operate, the increasing volume of solidification/stabilization

products is rather huge. Since inorganic salts’ content from the fly ash like chloride and

sulfate is quite high and CaCl2 caused by solidification reaction will lead to the

solidifying object’s expansion and crack due to the moisture absorption function, the

solidifying object’s long-term stability and heavy metals leach properties after landfilling

will be affected; meanwhile, problems like dioxins from incineration fly ash will not be

properly addressed as well. The strength of 28d cement solidifying objects from

incineration fly ash is only 0.35-0.70MPa. However, the safe landfill disposal should

still be conducted and the expense therefore increases so that the treatment cost of

cement solidification is generated.

136. In addition to cement solidification technology, technologies like bitumen

solidification, plastic materials’ solidification, self-cementation solidification and

containing-stabilization are all adopted. However, due to the technical characteristics

and economic reasons, they are rarely applied to the treatment of MSW incineration

fly ash.

137. Fly ash after cement solidification can be used for construction or as


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supplement for road subgrade. But this application is very limited. Generally, fly ash

treated by cement go to the landfill. The leaching concentration of the pollutants in the

fly ash after pretreatment meets the requirements of GB 16889, which can be disposed

in municipal solid waste landfill. The total amount of heavy metals in fly ash pretreated

by detoxification does not meet the requirements of GB30760, but the leaching toxicity

of heavy metal meets the requirements of GB 5749, and the dioxin content is below

80 ng I-TEQ/kg, which can enter the general industrial waste landfill site.

4.1.1.2 Chelate Stabilization – Sanitary Landfill Technology

138. Chemical stabilization refers to the process of transferring poisonous and

harmless materials into materials with low-solubility, low-transferability and low-toxicity

ones with chemical agents through chemical reactions. Disposing hazardous wastes

with chemical stabilization treatment will achieve low capacity increase or no increase

to improve the overall efficiency and economy of the hazardous wastes treatment and

disposal system at the same time of accomplishing harmless wastes treatment.

Meanwhile, improving the structure and property of chelate can strengthen its chemical

chelate efficiency with hazardous components from the wastes so as to improve the

long-term stabilization of stabilized products and reduce such products’ effect to the

environment during the final disposal process.

139. The fly ash treated by chelate method can be disposed into ordinary sanitary

landfill. The landfill site can be constructed in accordance with the requirements of

hazardous waste landfill site. The fly ash needs to meet the admission requirements

of hazardous waste landfill site.

140. Chemical addictive from the incineration fly ash’s stabilization treatment can

be mainly divided into two groups – inorganic heavy metals’ stabilized agents and

organic liquid chelates, among which, inorganic heavy metals’ stabilized agents are

usually sulfur compounds and phosphate compounds, constraining the heavy metals’

dissolution by forming heavy metals sulfide or similar insoluble materials like

Pb5(PO4)3OH. Organic liquid chelates are mainly alkaline agents with sulfur,

possessing functional groups of dithiocarbamic acid and polymerized substance with

alkyl structures. The basic principle of chelate stabilization is to dissolve soluble heavy

metals from the incineration fly ash and generate dissoluble reactants by the ligand


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bonding and iconic bonding reactions between electrophilicity with sulfur parts and

heavy metals in the aqueous phase so as to stabilize the heavy metals.

141. Currently, several researches combines cement solidification and chemical

stabilization together, i.e., combining the chemical addictive with heavy metals for the

stabilization treatment to reduce the heavy metals’ solubility and transferability, to

make up the long-term instable shortcomings of cement’s solely application and

strengthen the strength of the solidifying objects.

4.1.1.3 Acidic Extraction

142. Acidic extraction reduces the inorganic acid’s pH value with hydrochloric acid,

dissolves heavy metals from the self-incineration fly ash system in the form of ions and

then generates dissoluble heavy metal compound by adding agents or partly

concentrating heavy metals via electro-chemical approaches such as electrolysis.

143. Neutralizing carbonation with fuel gas takes advantages of carbonic acid or

bicarbonate generated via dissolving CO2 from fuel gas into water, as well as its

reaction with heavy metals from incineration fly ash to produce insoluble carbonate or

hydroxide to remove heavy metals from the incineration fly ash.

144. The combination between acidic extraction and chemical stabilization can

highly reduce the final waste amount that requires final disposal. However, such

approach lays great emphasis on controlling the pH value within a reasonable scale

and requires complicated operating conditions. It also need follow-up treatment on the

waste liquor and heavy metals sludge.

4.1.1.4 High Temperature Melting And Vitrification

145. High-temperature melting and solidification, also known as vitrification, brings

incineration fly ash into the melting status with a temperature (1200℃-1500℃) higher

than the material’s melting point. During such process, organic wastes like dioxins will

be dissolved while inorganic wastes will be melted into tight but stable glass slags.

Heavy metals will be strictly confined to the melted glass to effectively control their

leach.


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146. Blend fly ash with slight glass vitrics and once the granulating and molding

process is conducted, such blend will be melted under the high temperature of 1000-

1400℃ for a period, usually about 30 minutes (the melting time varying with the fly

ash’s properties). After the fly ash’s physical and chemical situation changes, cool it

down to promote its solidification. The blend will turn to glass solidifying object and the

stability of heavy metals will be ensured by the glass’s tight and crystal structure.

Residue produced by melting and solidification can be used for resource utilization.

But it requires plenty of energy and expenses.

147. Melting treatment has great effect of weight-reducing and capacity-reducing.

Under 1500℃, chloride will basically be volatilized and the fly ash amount can be

reduced by two-thirds. Meanwhile, the heavy metals’ leach rate after melting is rather

low and can meet the temporary leach toxicity standard. Under 1400℃ , PCDDs

/PCDFs from the fly ash will be degraded.

148. Based on the heat sources’ difference, melting and solidification can be

conducted with two approaches – fuel-combusted heat and electric heat. Incineration

fly ash will be melted into liquid under the high temperature of 1300-1600C, with its

organic materials thermolyzed, combusted and gasified and its inorganic materials

melted into glass slags. After melting, dioxins and other organic wastes from

incineration fly ash will be decomposed and destroyed after heating. As shown by the

test results conducted with several Japanese fly ash electric melting treatment burners,

the high-temperature decomposition rate of wastes like dioxins from the slags can

reach over 99.9% after the treatment. Part of heavy metal salts with a low boiling point

from the incineration fly ash will be gasified while others transferred into glass slags.

Besides, SiO2 from the fly ash will turn to Si-O network structure during the melting

process so as to surround heavy metals transferred to the slags into network structures

and reduce the leach possibility of heavy metals.

149. Fly ash which is not detoxified by heavy metal and dioxin detoxification cannot

be recycled as a recycling product. The products of high temperature sintering and

products prepared by fly ash with heavy metal detoxification and dioxin detoxification

can be used as building materials, subgrade accessories, and green construction

materials. It should not be used as food, interior decoration, residential buildings, water

conservancy projects and other accessories materials.


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4.1.1.5 Comparison of Fly Ash Treatment and Disposal Technologies

150. Table 4-1 comprehensively compares the above-mentioned four incineration

fly ash treatment technologies and helps you grasp a clearer understanding of the

status and developing tendency of incineration fly ash treatment with analysis.

(1) Diverse incineration fly ash treatment technologies have their own merits and

demerits: cement solidification is low-cost, but with a bad capacity-reducing and long-

term stability; high-temperature melting can fix the heavy metals effectively, but it is

energy-consuming and high-cost; chemical stabilization can generate stable

compounds, but is high-cost and the dioxins are not properly disposed as well; acidic

extraction requires other agents to get in operation and the residue should also be

further disposed.

(2) High-temperature treatment is the most promising technology that can completely

decompose dioxins from the incineration fly ash, reduce heavy metals’ leach rate as

well as the waste volume and its products also occupy the value of resource utilization.

(3) All these incineration fly ash treatment technologies have the problems of

secondary pollutants discharge and bad long-term stability during the treatment

process and require corresponding solutions. For example, the volatile amount

generated from the incineration fly ash melting process is over 30%, especially, the

large amount of acidic gases and heavy metals from the volatiles set rather high

requirements for the fuel gas management system.

Table 4-1 Comprehensive Comparison Between Incineration Fly Ash Treatment Technologies

Advantages Disadvantages

Cement solidification

Mature, easy to operate;

Many application results at

home and abroad;

Raw materials accessible and

low treatment expense.

High capacity-increasing, about 20%;

Low products compressing strength, necessary landfill disposal;

Necessary maintenance and storage space;

Ineffective wastes disposal such as dioxins;


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Advantages Disadvantages

Long-term leach possibility of solidifying objects

Chemical solidification

Stable products with great long-term safety;

Mature system and application

results at home and abroad;

Easy to operate and low space demand.

Product with no reusability, disposed by landfilling

Patented agents, high selling price;

Ineffective wastes treatments like dioxins;

Certain capacity-increasing, necessary maintenance and storage space.

Acidic extraction

Low construction and operation cost;

Able to be converged into the plants’ waste water treatment process

Generated waste water and sludge require further treatment;

Complicated operation and control, difficult application;

Ineffective wastes treatments like dioxins;

Product with no reusability, disposed by landfilling

Melting and solidification

Capacity-reducing rate over 60%;

Complete decomposing of materials like dioxins;

Stable slags properties and high reusability.

Energy-consuming, with a treatment expense about RMB 2000yuan/t

Huge secondary fly ash amount, further tail gas treatment;

Complicated treatment process, high-level technical requirements;

Huge volatile amount of acidic gases and heavy metals

4.1.1.6 Underground Storage Technology

151. Fly ash underground storage technology places the fly ash in a container and

stores it for long periods of time in underground mines or caves that are isolated from

the biosphere. At present, the technology is mainly used in Germany and France. It is

considered to be the safest disposal method with the lowest risk to human health and

environment and the possible risk to the least. Geological conditions for underground

storage should be long-term stability, with good geological barriers and areas of

sufficient depth (up to 400 meters) with no groundwater present in the area and poor

permeability of the formation. The selected area is safe and should not interfere with


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mining operations, At the same time have the necessary measures to store waste.

152. Underground storage technology preferred rock salt ore mines, because the

mine is located deep underground, very dry, with the stable distribution, moisture and

gas permeability, and self-healing ability. Followed by the choice of gypsum mine,

metal mine (dry), coal (dry), clay and other minerals mines. However, the rock salt

resources in China are abundant and widely distributed. There are large-scale salt

mines buried in the underground 10 to 4000 m, mainly distributed in northern Jiangsu,

southern Jiangsu, Anhui, Shandong, Hubei, Sichuan and Yunnan. Ore body is

generally layered, like layered or lenticular, smooth shape, thick, with the construction

of underground storage of hazardous waste geological conditions. It should be said

that China meets the requirements of basic geological conditions in the disposal of fly

ash underground storage technologies. However, due to the relatively large population

density in China, the relevant laws, regulations, theoretical systems and technical

methods have yet to be further studied, making the actual application still a long way

to go.

4.1.2 Utilization and Utilization Methods of Fly Ash Resource

4.1.2.1 Resource Utilization Approaches of Fly Ash

153. Due to the high soluble salts content, leachable heavy metals content and

organic pollutants content of the fly ash are all relatively high, fly ash’s resource

utilization rate is rather low. The fly ash’s resource utilization approaches should be

prudently evaluated while selecting. The major considering factors are as follow:

❖ Suitability of the treatment approach. Mainly consider the fly ash’s physicochemical properties;

❖ Feasibility of the treatment approach. Consider its operability and the products’ practicability;

❖ Economy of the treatment approach. Consider its technical economy;

❖ Environmental effect evaluation of the treatment approach. Make sure the

treatment process is environment-friendly and the final products are not new

pollutant sources.

154. In view of the above factors, fly ash’s resource utilization can be classified into

four categories: the first is construction class, including cement products, concrete


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products, pottery and glasswork or glass-ceramic products; the second is geology

class, including road-paving materials and embankment materials; the third is

agriculture class, mainly referring to soil conditioner; the fourth class includes

adsorbent and sludge conditioner. Taking the successful resource utilization

experience of fly ash overseas as a reference, we should still remain prudent while

selecting the MSW incineration fly ash’s resource utilization in China.

155. Table 4-2 shows the comparative analysis on diverse application approaches

of MSW incineration fly ash. All approaches use fly ash after sintering treatment except

for sludge conditioner which used raw fly ash without treatment.


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Table 4-2 Comparative Analysis on Diverse Application Approaches of MSW Incineration Fly Ash

Application

Approaches

Application

Level Pre-treatment Cost

Possible

Application Infiltration Advantages Disadvantages

Cement

products High Recommended Middle

Silicon aluminate and

other cement

products

Low

Wide cement origins and

low price;

Simple treatment

techniques and operation;

Low treatment expenses

Large amount of

cement

Heavy metals,

soluble chloride

and sulfide from

the fly ash will

affect the cement’s hydration process

Concrete

products High Recommended

Middle/

Low

Concrete products for

civil constructions,

isolate and low-

density products

Low Reduce disposing wastes;

Improve cement properties

Increase the

concrete’s hardening time;

Slightly reduce the

strength

Pottery Relatively high - Middle Sidewalk and

household tiles Low

Reduce disposing wastes;

Recycle energy -

Road-paving

materials Middle Necessary Low

Filling materials;

cement products Low Low treatment expenses -

Embankment

materials Low Recommended Low

Filling materials;

cement products

Middle/Hig

h Easy to operate

Beyond-standard

leach rate


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Application

Approaches

Application

Level Pre-treatment Cost

Possible

Application Infiltration Advantages Disadvantages

Sludge

conditioner Low Unnecessary High Chemical conditioner - Easy to operate

Increase heavy

metal content of

the waste water

Cementing

material Middle Unnecessary Low

Cementing material

for mine filling Low

Reduce disposing wastes; Simple treatment

techniques and operation

soluble chloride

from the fly ash

will affect the

quality of

cementing material


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4.1.2.2 Safe and Sustainable Reuse of Fly Ash

156. Safe landfill of fly ash refers to a way of fly ash burial after innocent treatment

and solidification or stabilization aimed to standardize the leach toxicity of fly ash at a

state level. The way is a final disposal of fly ash, the only choice under limited economic

conditions and without proper resource utilization. However, it comes with such

disadvantages as occupying amount of land resources, discharging quantity of heavy

metals and dioxin which remain be in scientists’ research for their long-term influence

on human’s health, and suffering objections for its landfill plant selection in almost all the cities. Therefore in terms of fly ash disposal, the safe resource utilization

technology not only guarantees the safety in its disposal, but also realizes the

sustainable resource utilization of the fly ash.

157. From the perspectives of recycling economy and waste utilization, safe

resource utilization technology of the fly ash from MSW incineration is an ideal way

among varieties of fly ash disposal ways. Currently a lot of researches have been

conducted on the safe resource utilization technology of incineration fly ash at home

and abroad, with a consistent idea that the pollutants with toxicity in the fly ash are

detoxified at first to meet the requirements of resource utilization, then resource

utilization approach shall be explored in accordance with characteristics of the fly ash,

simultaneously the resource utilization of fly ash is realized.

1) Cement Kiln Co-disposal Technology

158. Because the incineration fly ash contains CaO, SiO2, Fe2O3 and Al2O3, which

also constitute some raw materials of concrete, so it can take the place of the above

raw materials in the concrete production. Cement kiln co-disposing technology can

achieve the innocent treatment, reduction and resource utilization of the fly ash and

thus has the following advantages: the calcination temperature of raw materials in

concrete kiln and the maximum temperature of the inside air can respectively reach

1450℃ and 2000℃, which are far beyond 850℃ and 1200℃ in incinerator and can

thoroughly destroy the structure of dioxin; The air can stay as long as 8s in section with

temperature over 1000℃; the alkali gas is favourable for the absorption of volatile

molecules, thereby effectively neutralizing HF, HCl and SO2; at 1450℃ , the

temperature of clinker reaction, the heavy metals can be solidified into the clinker in a

chemical way, and due to the compactness of the hardened cement paste, the harmful

pollutants will be effectively solidified in the paste after proper processing; because of

the high cooling rate of waste gas, the compound of dioxins and furans is also

prevented.

159. However, the cement kiln co-disposal of fly ash also has some shortcomings:

in order to ensure the characteristics of cement and reduce the secondary pollution of


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volatile substance in the disposal process, the content of fluorine and chlorine in the

materials into the kiln should be strictly controlled. Therefore, the dechlorination pre-

treatment is a must before the use of the cement kiln co-disposal of fly ash. In the

practical application of water washing dechlorination, a large amount of washing

wastewater with high salt content will be produced and needs be further treated, which

will inevitably increase the treatment difficulty and costs. In addition, the cement kiln

co-disposal process of fly ash is going to solidify the heavy metal into cement products,

meaning that the total amount of heavy metals is not reduced and there are still

potential hazards.

2) Sintered Ceramsite Technology

160. Sinter treatment technology is based on the experience of the material

industry; it, below the melting point temperature, provides the diffusion energy of the

powder particles, and removes most or even all the pores away from the crystal, the

particles between the bond, thereby the materials will turn into a compact and hard

sintered body, which meets the requirements of various material properties, below the

melting point temperature; the sintering temperature is usually between 1/2 and 2/3 of

the absolute melting temperature of the main components in the powder. From the

view of the microcosmic significance, in the process of sintering, the material migrating

and bonding is due to the mutual attraction of molecules (or atoms) and by heating the

powder particles, which finally renders the sintered body with a certain mechanical

strength, and gives rise to the emergence of densification and recrystallization.

161. An important advantage of high-temperature sintering technology is that sinter

products of incineration fly ash can be used for resource utilization. On the one hand,

the sinter products already have the various properties required for building aggregate

and can be used directly as roadbed materials or other building materials; on the other

hand, the sinter products can replace the natural aggregate for the pouring of ordinary

concrete and can meet the relevant requirements of concrete performance.

162. The quality of the product obtained by the sintering treatment (such as

strength, density, shape, etc.) is affected by the sintering temperature, the rate of

temperature rise and the sintering time. It is also affected by the composition of fly ash,

the particle size and the additive. In addition, content of some of the alkali metals,

alkaline earth metals, chlorides and sulfates in fly ash also have some influence on the

sintering process conditions and sintered products. During the sintering process, most

of the heavy metals are cured in the sintered body, their leach probability is greatly

reduced, and the small part of the heavy metals are volatilized in the form of gas, which

causes secondary pollution, this is more prominent for the low boiling point elements

such as lead, zinc and cadmium. Therefore, the fly ash sintering process also needs

to use the washing process to remove chlorine and sulfate.


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3) Leach Technologies of Heavy Metal

163. The main leach way of heavy metals in fly ash are: washing method, chemical

leach (acid leach, alkali leach), high temperature leach, biological leach and other

pharmaceutical leach.

➢ Washing Leach

164. The purpose of this process is to use water solvent as leach agent to reduce

the salt (chloride, etc.), alkali and heavy metal substances in order to improve the

product grade after the pre-treatment of fly ash at the same time of reducing the

environmental and biological risks, thereby enhancing product utilization value. The fly

ash is rich in high concentrations of soluble salts, mainly such as chloride, bringing

about difficulties for the fly ash solidification and stabilization and resource utilization

process. So dechlorination is an important part in the fly ash disposal process. At

present, fly ash dechlorination technology is still relatively simple; the chloride into the

fly ash will be transferred into the liquid phase mainly through the water transfer

technology, and then the solution needs to go through the dechlorination treatment.

The main purpose of this technology is to effectively remove the dissolved salts with

high concentration in the fly ash, making the early preparation for the subsequent

solidification, metal recovery and other treatments. The main removal targets in the

washing process are Cl, Na, K and Ca in fly ash, and the removal rate of Cl is the

highest. After washing with water, the XRD map shows KCl and NaCl are the main

dissolution forms of K, Na and Cl. However, it is worth noting that some of the heavy

metals during the washing process can be dissolved into the washing solution, and the

solution before reaching the standard of being discharges is still required to be treated.

➢ Chemical Leach (Acid Leach And Alkaline Leach):

165. The purpose of this process is to transfer the heavy metals in the fly ash into

the liquid and then separate and recover them, and make the fly ash become the

general waste with low toxicity or convert it into building materials and other secondary

materials for resource utilization; in order to achieve this point, heavy metals

concentration must be high enough to ensure the recovery.

166. Chemical leach is to use chemical agents and fly ash reaction to leach heavy

metals into the solution, and then to recover heavy metals through the chemical and

other methods. The leach process of heavy metals usually depends on the type of

leach agent, leach time, temperature, pH and ratio of liquid to solid. Commonly used

agents include inorganic acids (HCl, HNO3 and H2SO4), organic acids (ethylic acid,

formic acid and oxalic acid, etc.), alkalies (NaOH and Na2CO3, etc.), complexing

agents (general complexing agents such as NH3 and chelating agents such as EDTA).

Leach effects of different acids are very different, the effect of inorganic acid is often


81

better than that of organic acid. Nitric acid and hydrochloric acid can leach almost a ll

of the metals. Sulfuric acid can leach the vast majority of metals except Ca and Pb,

and because the high Pb content in fly ash is a major source of fly ash toxicity, so the

other acids or alkali leach should be added after the sulfuric acid leach; organic acid is

only better for some heavy metal leach; alkali can selectively leach amphoteric metals

such as Zn and Pb; complexing agent selectively coordinate with heavy metals of fly

ash to be complexant which then dissolves itself into solution, but the complexation of

the complexing agent on heavy metals has a strong ion selectivity, and will be affected

greatly by the pH of the solution, the same complexing agent at different pH varies

greatly in its complexing performance. Since the poorly soluble hydroxides are easily

formed at higher pH, so the increase in pH of the leachate may reduce the leach-out

rate of heavy metals.

➢ Biological Leach

167. Biological leach technology is another leach technique in addition to

chemical leach. The leach principle is similar to that of chemical leach, except that the

leach solution is different. Biological leach technology is derived from a bio-

hydrometallurgical method for the leach of ore metals or lean ore metals that are

difficult to be leached, it is a forward-looking fly ash metal leach technology that has

advantages of low acid consumption, high leach-out rate of heavy metals and strong

practicability and other advantages compared to chemical leach. The method mainly

uses the direct action of the specific microorganism or the indirect actions of the

metabolism, such as reduction, oxidation, complexation and adsorption or dissolution,

to convert the insoluble heavy metals into soluble metal ions, and after this process

from the solid phase to the liquid phase, the heavy metals are recovered through the

electrochemical and other methods. Factors affecting the efficiency of the leach

process of heavy metals are temperature, oxygen concentration, CO2 concentration,

initial pH, mineral composition, inhibitory factors, bacteria and so on. Currently

available biological agents for biological leach are mainly steroidal sopnin, aspergillus

niger and sulfur-oxidizing bacteria.

➢ Electrochemical Leach

168. The purpose of electrochemical technology is to remove heavy metals from

fly ash and recycle them. The process involves the use of potential to drive the

reduction and oxidation reactions on the cathode and anode. In this process, the metal

precipitates on the surface of the cathode; although this process does not require the

addition of chemical reagents, the recovery efficiency is low, indicating the technology

can be combined with other technologies such as leach extraction to eventually

recover heavy metals from the solutions.

➢ Supercritical Fluids Leach:


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169. Supercritical Fluids Leach (SFE or SCFE) is a process of separating and

purifying a target from a liquid or a solid on the basis of the principle that the solubility

of the mixture is greatly changed by the small change of liquid in pressure and

temperature in the supercritical state. Because CO2 has a low critical temperature with

non-toxic and low-cost advantages, it has become the most commonly used

supercritical fluid solvent. However, due to the strong polarity of heavy metal ions and

the weak Van der Waals Force between the non-polar supercritical CO2, it is often

necessary to add a small amount of entrainment to the system to improve the solubility

of heavy metals and reduce the leach pressure and the SFE cost.

4.1.3 Fly Ash Pretreatment Technology before Treatment/Disposal

170. In order to meet the requirements of the technical specifications for fly ash

solidification/stabilization landfill disposal or the ecological cement or other resource

utilization by cement kiln co-disposal, pretreatment of the fly ash by water washing,

microwaves and pyrolysis is generally required.

4.1.3.1 Dioxins Pretreatment Technology by Microwave Pyrolysis

171. Through washing pretreatment, sewage treatment, calcination of cement

clinker three main processes, using secondary countercurrent rinse, coprecipitation,

multi-effect evaporation, special filter aid and many other advanced technology and

technology, the heavy metals, chlorine salts and other harmful ingredients of fly ash

can be effectively remove. Materials and energy can be recycled to achieve the effect

of reduction, recycling, and harmless in the process of treatment. Figure 4-1 is a

diagram of fly ash washing pretreatment and cement kiln co-processing process.

172. The demonstration line handles 40 tons of fly ash daily on average, and

annual fly ash handling capacity exceeds 10,000 tons. With the further development

of technology, the daily fly-ash disposal capacity is expected to reach 100 tons in 2018,

and the annual disposal capacity will exceed 30,000 tons. The cement produced by

this method for handling fly ash meets the performance requirements of GB175-2007

"Universal Portland Cement". The test results are shown in the Figure 4-1.


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Figure4-1 Cement Plant Fly Ash Pretreatment and Cement Kiln Co-processing

Process Flow Chart of Beijing Liulihe

4.1.3.2 Dioxins Pretreatment Technology by Microwave Pyrolysis

173. Tianjin Yiming Environmental Science and Technology Company built and

began to run MSWI fly ash dioxin microwave detoxification detoxification project

demonstration line by using microwave local heating to remove enriched dioxin in fly

ash in 2009.

(1) Technical Principle

174. Activated carbon accounts for about 1%-3% of waste incineration fly ash,

which is a strong absorbing substance, and activated carbon is the main carrier of

dioxins and volatile heavy metals. Under the microwave irradiation, when the macro-

temperature of the fly ash reached 600 ℃, the temperature of the local micro-area of

activated carbon particles with strong absorbing material exceeded 1250 ℃. Dioxin

contaminants adsorbed on the activated carbon are pyrolyzed or desorbed at high

temperatures; volatile heavy metals are also desorbed into the flue gas; and the less

volatile heavy metals are further melted and solidified.

175. After microwave heat treatment, the content of dioxins in the fly ash is

extremely low, and a small amount of residual heavy metals are basically present in

the residual state, so that they have the conditions of disposal and utilization according

to the general solid waste. The secondary fly ash enriched with relatively high

concentrations of contaminants need to be strictly handled.

Fl Ash Washi g

Wet Ash E aporatio

Re li g Salts Deh dratio

Ce e t Ra Material

Reli

g Water

Water

Mix, Dilution

Reage ts

Ce e t Kil e e t Flue Gas a d Dust Co trol S ste


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(2) Technology Process

Fly Ash Microwave Heating and Flue Gas deep Purification Process

176. Fly ash - Unloaded from the fly ash storage tank, after measurement by the

screw conveyor into the microwave heater with a feeding speed of 8.0t/h-9.0t/h, fly ash

stay in the microwave heater for about 20min, Heating average temperature of 600 ℃,

the fly ash in more than 99.5% dioxin digestion.

177. Exhaust gas - Microwave heaters and cooling heat transfer devices are

negative pressure operation, the first out of the exhaust gas into the deacidification

equipment, removal of acidic substances, and then the exhaust gas dust trapped by

the efficient bag filter, and then exhaust gas from the dust collector into the atmosphere

through a deep purifying of the activated carbon fiber adsorption device.

178. Secondary ash - The amount of secondary fly ash collected by the precipitator

in the exhaust gas treatment process is 0.2-0.6t/d, which is stabilized /solidified for safe

landfilling.

Stabilized Process

179. The fly ash discharged from the microwave heater, cooled to below 50 °C by

means of an efficient heat exchange device. The heavy metal stabilizing agent is dosed

into an aqueous solution with a mass concentration of 3% to 6%, sprayed into the fly

ash of waste incineration with addition about 15% by weight of the fly ash, and then

fully mixed fly ash with the curing agent in the mixer, so that most of the heavy metals

can be stabilized.

Curing Process

180. Stabilized fly ash was into the pelletizing machine extrusion granulation to

produce artificial stone, the artificial stone for natural conservation with curing

conditions of more than 4℃ for 1 day, and then the finished product was sent to the

yard to continue conservation of stockpiling.


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Figure4-2 Microwave Detoxification Demonstration Project Process Chart

4.1.3.3 Dioxins Thermal Decomposition Pretreatment Technology with Low

Temperature

Figure 4-3 Dioxins Low Temperature Pyrolysis Process Flow Chart

Fl Ash

Pyrolysis Process Devices

Pretreat e t

Cooli g

Flue Gas Mo itori g S ste

Deto ifi atio Produ ts


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181. "MSWI Fly Ash Dioxin Low Temperature Thermal Degradation Technology

and devices" project is development and construction by China Academy of

Environmental Sciences and Chongqing Sanfeng Environmental Industry Co., Ltd,

which completed China's first industrial scale project demonstration line with

independent intellectual property rights for dioxin of fly ash low temperature thermal

degradation. The toxic equivalent concentration of dioxin after detoxification is less

than 10ng-TEQ/kg by the whole process of low temperature thermal degradation of

dioxin in MSWI fly ash. MSWI fly ash dioxin low temperature thermal degradation

technology and key special devices have independent intellectual property rights,

which the research results of are the first in the country. As a whole, the technology

reached the international advanced level, and dioxin low temperature thermal

degradation of the directional control reached the international advanced level. The

project passed the certification of environmental science and technology of China

Institute of Environmental Science in September 2014 (CIESI [2014] No. 32).

4.2 Environmental Impacts of Fly Ash Disposal Technologies

4.2.1 Fly Ash Disposal Technologies

4.2.1.1 Cement-based Solidification – Treatment in Hazardous Waste Landfill Plant

182. The technology employs cement-based solidification technique as a means

of pre-treatment, but the latter method requires large addition of cement, after

treatment, the 30% to 50% increase of capacity will take up a lot of landfill room;

solidification body is vulnerable to acidic media erosion with great possibility of heavy

metal leach and can’t achieve the degradation of dioxin-like organic pollutants; fly ash

contains salts with high concentration, easily leading to solidification ruptures, reducing

structural strength and increasing permeability; in the links of storage and mixing of fly

ash and cement, it is easy to produce dust causing harms on the environment and the

human body. Hence it is necessary to install bag filter in the top of the tank, feeding

room and product outlet and other places, minimizing dust emissions with dust removal

rate up to 99.5% and reducing environmental impacts.

4.2.1.2 Stabilization of Chelate - Sanitary Landfill

183. In China, the issue of Landfill Pollution Control Standards of Municipal Solid

Waste(GB16889-2008) has promoted the landfill disposal of incineration fly ash, but

fly ash landfill also takes up a lot of land resources, consumption of landfill plant

operating for many years of the national regions is being intensified ; Selection and

construction of the new landfill plant suffers great resistance, so fly ash landfill disposal

can alleviate the urgent needs, but its sustainability has been challenged.


87

184. In addition, due to the complex diversity of fly ash components and heavy

metal forms and the lack of sufficient understanding of the mechanism of chelation

reaction, it is difficult to find a universally applicable chemical stabilizer for stabilization

pre-treatment of fly ash, resulting in poor stabilization of heavy metals, and that the

stabilization effect on dioxins is also very small. It is prone to produce dust in the

process of fly ash collection, transportation, dumping and others, which can cause

serious harm on the atmosphere and human health. Compared with the hazardous

waste landfill plant, the seepage control function of ordinary landfill plant is weak,

encountering the rainfall or landfill leachate, the heavy metals in the fly ash may be

leached out, resulting in the secondary harm.

185. Therefore, in the process of collecting and transporting fly ash, it is necessary

to take strict anti-leakage measures; places where are easy to produce dust need to

be equipped with dust-removal facilities, and to be washed and sprayed by the washing

vehicle and sprinkler which can effectively prevent secondary pollution of fly ash; in

the fly ash loading and unloading, the landing height shall be reduced, and transport

vehicles shall use a fully enclosed way to undertake the transport, loading and

unloading. It is also to strengthen the anti-seepage structure of MSW landfill plant and

guide leachate out timely. At the same time, the landfill gases generated by landfill

shall be collected and discharged through the high combustion tower after its

combustion; SO2 emission concentration shall reach the standard of Integrated

Emission Standards of Air Pollutants.

4.2.1.3 Melting Technology

186. The melting technology has the advantages of high capacity reduction rate,

stable slag, low leach-out rate of heavy metals, decomposition of dioxins, etc. However,

this high-temperature treatment requires a lot of energy, and the alkali metal chloride,

and other volatile metal compounds generate large amount of fuel gas of acidic gas in

the melting process, especially for the heavy metals with low boiling point, volatile

phenomenon is more obvious; heavy metals in the form of gaseous evaporation may

cause new environment pollution. The melt-solidifying process requires a rigorous

follow-up flue gas treatment, meaning this technology has high energy consumption

and high treatment costs.

4.2.1.4 Underground Storage Technology

187. Underground storage technology of fly ash is considered to be the safest

method of disposal with minimal risk to human health and the environment, with the

lowest possible risk of harm. However, the requirements of suitable conditions such as

the type of mine to be accepted and the hydrogeological conditions are extremely strict.

It is not that any type of mine is suitable for use as a mine for storing and storing fly

ash. Underground salt mines resources in China is rich and widely distributed, choose

to do mine application of fly ash storage should be strictly in accordance with the


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conditions of choice, and in accordance with the requirements of the construction to

prevent the long process of storage of fly ash harm to the environment.

4.2.2 Safe and Sustainable Utilization

4.2.2.1 Cement kiln Co-disposal Technology

188. Taking the cement kiln co-disposal of fly ash as an example, cement is a

finished product after through high-temperature calcination and grinding in the cement

kiln when it is the mixture of limestone (the main component is CaCO3), clay and other

materials. Fly ash contains a large amount of CaO rather than CaCO3, if it is used as

a raw material for cement production, the energy consumed by limestone during the

calcination process and the release of CO2 from limestone, which has a positive effect

on mitigating global warming.

189. In the cement kiln co-disposal of fly ash, the new waste gases are divided into

two parts, one is the waste gases produced in production line of cement while f ly ash

is treated, containing Pb, Cu, Cr and dioxin emissions, this part of exhaust gases is

the main source of waste gases in the project of the cement kiln co-disposal of fly ash;

the other is waste kiln gases entering the CO2 reaction tank. Because the washing

wastewater is alkaline which can effectively absorb the waste kiln gas such as SO2,

TSP, therefore, the part of the exhaust gases can’t be included in the focus analysis. Some of the Pb, Cu, Cr and other heavy metal elements in the fly ash are released

into the environment with the exhaust emission, some are solidified in the cement

clinker, and another part will be adsorbed in the dust, waiting for being collected and

returning to the raw material system, returning into the cement kiln for calcination.

Studies have shown that most of the heavy metal elements are solidified in the cement

clinker, little in the circulation of kiln ash in the kiln system and less in exhaust gases.

After cement-based solidification and bag filtering, the concentration of new exhaust

gas with heavy metals can reach the emission limit of Solid Waste Pollution Control

Standards in Cement Kiln Co-disposal. For modern new type of dry treatment, kiln

temperature can be heated to above 1500 ℃ quickly, and more than 99.9% of the

dioxin will be broken down, in clinker cooling process the temperature can be quickly

reduced to below 300℃, during which dioxin synthesis rate is also very low. Secondly,

even dioxin substances regenerate in the process of flue gases cooling down, most of

which will be gathered in dust filter system, and return to clinker firing system as the

cement production raw material, so that dioxin can be almost fully decomposed. In the

cement kiln disposal of fly ash, technology of high-temperature heating and speed

cooling can almost completely decompose dioxin substances, thus dioxin emissions

can meet the emission limit of Solid Waste Pollution Control Standards in Cement Kiln

Co-disposal.

190. However, the content of heavy metals with high toxicity in incineration fly ash


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such as lead, cadmium and mercury are generally 2 to 3 grades higher than that in

cement raw materials. In the process of water washing pre-treatment, precipitation

agents are usually added to make heavy metals as much as possible stay in the solid,

while a large amount of high-salt wastewater is produced and needs further treatment,

increasing treatment difficulty and costs. In terms of the rough material balance, even

if the fly ash only 1% of the mixing ratio into the cement kiln co-disposal, it will also

increase the heavy metal content in cement by 1 to 10 times. In addition, most of the

heavy metals, such as lead, cadmium and mercury, are volatilized into the flue gas

during the calcination process. Most of the lead, cadmium and about 50% of the

mercury are trapped into the kiln dust; the cement kiln dust will not be under the waste

management, but return to the kiln to be calcined once more or to mix directly with the

cement clinker, becoming part of the cement product, so that actually the heavy metals

are diluted into the cement products, increasing the risk of its slow release into the

environment and simultaneously producing the additional emission of mercury into the

atmospheric environment.

4.2.2.2 Sintered Ceramsite Technology

191. Through new treatment technology and flue gas purification process of “high temperature chlorination calcination + secondary combustion + quenching cooling +

semi-dry absorption + activated carbon powder + bag dust filter”, the sintered ceramsite technology can effectively remove a variety of acidic gases, harmful heavy

metals and dioxin-like organic pollutants, etc., and the flue gas after purification is

much higher than China's emission standards. The purification and removal process

of the pollutants are as follows:

192. Dioxins: During the high-temperature sintering (1200-1350 ℃ ), the vast

majority of dioxin pollutants are going to be degraded, and the undegraded part can

be fully degraded when it goes through the secondary combustion chamber (the

residence time at over 1100 ℃ is greater than 2s), then the flue gases cool down to

200 ℃ below after through quench deacidification, avoiding the re-synthesis

temperature range of dioxins, and finally part of dioxins that may escape will be

absorbed by the use of activated carbon.

193. Heavy metals: Heavy metals (such as Pb, Hg, Cd, Zn, etc.), easily volatile in

high-temperature sinter, react with the chlorine salts in fly ash to produce metal

chlorides. The boiling points of chloride salts with heavy metals reduce significantly as

shown in Table 4-3; chloride salts with heavy metals follows the flue gas into the flue

gas treatment system, and enters the secondary fly ash system after adsorption of the

activated carbon and collection of bag dust filter, and the secondary fly ash is put into

a centralized disposal; heavy metals of fly ash not easy to volatile are solidified in the

ceramic at high temperature; finally content and leach amount of the heavy metals in

the ceramic granules will decrease with each other, reducing the potential hazards to


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the environment when the ceramic products are used.

Acidic gases: After quenching-deacidification process and adsorption of activated

carbon with incomplete reaction, the acidic gases will be collected in bag dust filter for

the secondary fly ash and put into a centralized disposal.

Particulate matters: The particulate matters will be absorbed by the activated carbon

adsorption, collected in bag dust filter for the secondary fly ash and finally put into a

centralized disposal.

Table 4-3 Boiling Points of Heavy Metals and Their Chloride

Metals Boiling

point/℃ Chloride Salts Boling point/℃

Pb 1740 PbCl2 950

Zn 906 ZnCl2 732

Cd 765 CdCl2 960

Cu 2567 CuCl2 993

Ca 1484 CaCl2 1600

Na 883 NaCl 1413

Au 2807 AuCl3 265(Sublimation)

4.2.2.3 Acidic Extraction

194. Water washing as an effective pre-treatment can significantly improve

disposal effects of cement solidification, cement kiln co-disposal, sintering / melting

and other methods, and also brings hope for the large-scale resource utilization of the

follow-up products (such as cement, light aggregate, etc.). However, some of the

heavy metals during the washing process can be dissolved in the washing water, so

the solution still requires to be treated before being discharged.

195. Heavy metal biological / chemical leach technology has the advantages of

simple process, strong operability and heavy metal leach and recovery. However,

because of the need for microbial culture and the procurement of various types of

chemical and chelating agents, the general costs of leach technology is relatively high, ,

and the heavy metal concentration in fly ash is generally very low, the recovered heavy

metals often can’t offset the cost of the required agents.

196. The heavy metal leach technology can improve the quality of fly ash and

improve its utilization, and recover part of heavy metals and salts in the fly ash, so that

the adverse effects of fly ash on the environment can be minimized and the use of fly

ash value is greatly improved.


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Tabel 4-4 Overview of environmental impact of different treatment

Treatment Principle/Process Environmental impact

Cement

Solidification

– Landfill

Technology

for Hazardous

Wastes

Cement solidification adds

Portland cement into incineration

fly ash to form high-strength

lumps similar to rocks and

hydroxyl with high basicity from

the cement can transfer heavy

metals into materials with low

solubility such as hydroxide so as

to intercept heavy metals.

1 30% to 50% increase of capacity will take

up a lot of landfill room; 2 solidification

body is vulnerable to acidic media erosion

with great possibility of heavy metal leach

and can’t achieve the degradation of dioxin-

like organic pollutants; 3 fly ash contains

salts with high concentration, easily leading

to solidification ruptures, reducing

structural strength and increasing

permeability; 4 in the links of storage and

mixing of fly ash and cement, it is easy to

produce dust causing harms on the

environment and the human body.

Chelate

Stabilization

– Sanitary

Landfill

Technology

Chemical stabilization refers to

the process of transferring

poisonous and harmless

materials into materials with

low-solubility, low-

transferability and low-toxicity

ones with chemical agents

through chemical reactions.

1 In the process of collecting and

transporting fly ash, it is necessary to take

strict anti-leakage measures; 2 places where

are easy to produce dust need to be equipped

with dust-removal facilities, and to be

washed and sprayed by the washing vehicle

and sprinkler which can effectively prevent

secondary pollution of fly ash; 3 in the fly

ash loading and unloading, the landing

height shall be reduced, and transport

vehicles shall use a fully enclosed way to

undertake the transport, loading and

unloading. It is also to strengthen the anti-

seepage structure of MSW landfill plant and

guide leachate out timely. At the same time,

the landfill gases generated by landfill shall

be collected and discharged through the high

combustion tower after its combustion; SO2

emission concentration shall reach the

standard of Integrated Emission Standards

of Air Pollutants.


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Melting And

Vitrification

Blend fly ash with slight glass

vitrics and once the granulating

and molding process is

conducted, such blend will be

melted under the high

temperature of 1000-1400℃ for

a period, usually about 30

minutes (the melting time

varying with the fly ash’s

properties). After the fly ash’s

physical and chemical situation

changes, cool it down to promote

its solidification.

Heavy metals in the form of gaseous

evaporation may cause new environment

pollution. The melt-solidifying process

requires a rigorous follow-up flue gas

treatment, meaning this technology has high

energy consumption and high treatment

costs.

Underground

Storage

Technology

Fly ash underground storage

technology places the fly ash in a

container and stores it for long

periods of time in underground

mines or caves that are isolated

from the biosphere.

Underground storage technology of fly ash

is considered to be the safest method of

disposal with minimal risk to human health

and the environment, with the lowest

possible risk of harm.

Cement kiln

Co-disposal

Technology

the incineration fly ash contains

CaO, SiO2, Fe2O3 and Al2O3,

which also constitute some raw

materials of concrete, so it can

take the place of the above raw

materials in the concrete

production. Cement kiln co-

disposing technology can

achieve the innocent treatment,

reduction and resource

utilization of the fly ash.

In the cement kiln co-disposal of fly ash, the

new waste gases are divided into two parts,

one is the waste gases produced in

production line of cement while fly ash is

treated, containing Pb, Cu, Cr and dioxin

emissions, this part of exhaust gases is the

main source of waste gases in the project of

the cement kiln co-disposal of fly ash; the

other is waste kiln gases entering the CO2

reaction tank.

Sintered

Ceramsite

Technology

Sinter treatment technology

provides the diffusion energy of

the powder particles, and

removes most or even all the

pores away from the crystal, the

particles between the bond,

thereby the materials will turn

into a compact and hard sintered

Dioxins: During the high-temperature

sintering (1200-1350 ℃), the vast majority

of dioxin pollutants are going to be

degraded.

Heavy metals (such as Pb, Hg, Cd, Zn, etc.),

easily volatile in high-temperature sinter,

react with the chlorine salts in fly ash to

produce metal chlorides. the acidic gases


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body, which meets the

requirements of various material

properties; the sintering

temperature is usually between

1/2 and 2/3 of the absolute

melting temperature of the main

components in the powder.

will be collected in bag dust filter for the

secondary fly ash and put into a centralized

disposal.The particulate matters will be

absorbed by the activated carbon adsorption,

collected in bag dust filter for the secondary

fly ash and finally put into a centralized

disposal.

Acidic

Extraction

Acidic extraction reduces the

inorganic acid’s pH value with hydrochloric acid, dissolves

heavy metals from the self-

incineration fly ash system in the

form of ions and then generates

dissoluble heavy metal

compound by adding agents or

partly concentrating heavy

metals via electro-chemical

approaches such as electrolysis.

Some of the heavy metals during the

washing process can be dissolved in the

washing water, so the solution still requires

to be treated before being discharged.

4.3 Cost-benefit Analysis of Typical Technologies

197. Treatment and disposal of fly ash must strictly comply with national

specifications. Technical standards of fly ash treatment technology directly affect the

level of treatment fee. In July 2008, Control Standards of MSW Landfill Pollution began

to be implemented, which provides that fly ash pre-treatment shall meet certain

conditions, so that the landfill disposal can be started. In 2016 National Catalogue of

Hazardous Wastes, the newly-added catalogue of hazardous wastes of exemption

management gets the MSW’s incineration fly ash involved, clearly stipulating the following standards of fly ash after through the treatments: 1) Moisture content shall

be less than 30%; 2) Dioxins content shall be less than 3ug TEQ / kg; 3) The

concentration of hazardous ingredients in the HJ / T300 prepared leach solution shall

be below the fixed limit.

4.3.1 Cost-benefit Analysis of Products

4.3.1.1 Safe Landfill Disposal

198. As early as 2008, fly ash was included in the National Catalogue of Hazardous

Wastes, and can only be disposed in the hazardous waste landfill plant at a fee of

about 2,000 yuan / ton. In 2008, Control Standards MSW Landfill Pollution came into

force, stipulating the fly ash can enter the MSW landfill plant for disposal after strict


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pre-treatment, thereby its treatment costs drops significantly to about 500-600 yuan /

ton. Solidification of chelate brings about high increase of volume and weight of fly ash,

inevitably leading to several times increase of fly ash treatment costs.

4.3.1.2 Cement Kiln Co-disposal

199. Fly ash is co-disposed through the process from Beijing Jinyu Liulihe Cement

Plant; with a total investment of about 110 million Yuan, a multi-stage technology and

equipment system need to be built, including countercurrent rinse, precipitation,

pressure steaming, separation, drying and dehydration, to reduce the content of

volatile elements (chlorine, sulfur, potassium and sodium, etc.) and heavy metals in fly

ash; first the fly ash should be washed and purified to the acceptable level of cement

kiln, so that it can be used as an alternative raw material entering the kiln and turn into

mature material after calcination. For Beijing Jinyu Liulihe Cement Plant, the original

fly ash into the plant has dry chlorine content of 22%, the annual disposal of fly ash

reaches 20,000 tons, and the disposal cost is very expensive with the price of 1400-

1700 yuan / ton.


200. Tianjin Yiming Environmental Technology Co., Ltd. carries out demonstration

project of preparation of high-temperature sintered ceramsites with incineration fly ash

of MSW, the ceramsite production capacity reaches 125,000 tons per year or so; in

terms of 40% mixture proportion of the fly ash, the production line can dispose 50,000

tons of fly ash.

201. From the construction and operation of the demonstration production line of

Tianjin Yiming Environmental Technology Co., Ltd., the construction cost of 50,000

tons of incineration fly ash is about 130 million yuan per year, the processing cost is

800-1000 yuan/ ton, and the treatment process has no obvious secondary pollution.

Other costs include the transport cost of fly ash to the plant (1 yuan / t • km).

4.3.2 Environmental Economic Benefits

4.3.2.1 Safe Landfill Disposal

202. Fly ash landfill will take up a lot of land resources, consumption of landfill plant

operating for many years of the national regions is being intensified; selection and

construction of the new landfill plant suffers great resistance, so fly ash landfill disposal

can alleviate the urgent needs, but its sustainability has been challenged.

203. Due to the complex diversity of fly ash components and heavy metal forms

and the lack of sufficient understanding of the mechanism of chelation reaction, it is

difficult to find a universally applicable chemical stabilizer for stabilization pre-treatment

of fly ash, resulting in poor stabilization of heavy metals, and that the stabilization effect


95

on dioxins is also very small. It is prone to produce dust in the processes of fly ash

collection, transportation, dumping and others, which can cause serious harm on the

atmosphere and human health. Compared with the hazardous waste landfill plant, the

seepage control function of ordinary MSW landfill plant is weak, encountering the

rainfall or landfill leachate, the heavy metals in the fly ash may be leached out, resulting

in the secondary pollution.

4.3.2.2 Cement Kiln Co-disposal

204. With limestone as the main raw material, coal-fueled cement industry is the

main industrial CO2 emission source; cement industry-wide CO2 emissions accounts

for 6% of global anthropogenic CO2 emissions. Cement kiln co-disposal of fly ash, at

the same time of the realization of fly ash reduction, also achieves the raw material

alternation in the cement production process, effectively reducing the CO2 emissions.

In cement production, calcium oxide and magnesium oxide of the raw material are

provided by carbonate minerals that will produce CO2 in the decomposition of

carbonate. Fly ash contains a lot of CaO which can reduce the release of CO2 in

decomposition of limestone.

205. According to the large amount of industrial experiments of Beijing Jinyu Liulihe

Cement Plant, the content of fly ash should not exceed 3% of the raw material quantity

so as to ensure the normal operation of the production line. The co-disposal has little

effects on the cement kiln and the quality of the cement product can thus be

guaranteed. For example, for production line of 2,500 t/d cement clinker, consumption

of raw materials per day is about 4,000t and the fly ash consumption is about 120t.

206. Ordinary silicate cement clinker contains about 65% of calcium oxide;

according to CaCO3 = CaO + CO2, each CaO is generated with the company of 0.7857

CO2, so the formation of 1t cement clinker will be accompanied by 0.511t CO2

emissions.

207. As the flue gas purification process varies, the content of CaO in fly ash is

quite different. If the CaO content of fly ash is 30%, taking production line of 2500 t / d

cement clinker as an example, when fly ash consumption is 120t , and CaO will be

about 36t and CO2 reduction reaches 36 * 0.7857 = 28.29t, the annual CO2 reduction

will be 360 * 28.29 = 1018.44t with annual fly ash consumption of 120 * 360 = 43200t.


208. Compared with other high-temperature treating technology, the sintered

ceramsite technology for fly ash has the advantage of low energy consumption, and

can solve pollution caused by the fly ash on the environment, effectively reducing the

concentration of particulate matters in the air and ecological toxicity of haze. With

innocent treatment and reduction of fly ash, it is possible to reduce the risk of potential


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environmental pollution of landfill by reducing the capacity of landfill plant, extending

the cycle of new landfill plant and saving land resources.

209. Through the application of low-energy and low-emission reduction treatment

and sintering disposal technology of MSW incineration fly ash, disposal of 50,000 tons

fly ash per year can annually reduce 33,000 tons of CO2 emissions, about 50,000 tons

of particulate matter emissions and 0.05 million tons of heavy metal discharge,

eliminate persistent organic pollutants of 50g and save about 50% of solid waste landfill

capacity.

4.4 Management Status of Municipal Solid Wastes Incineration Fly Ash in China

210. Chlorine is an essential component of MSW in China. In one hand, there is a

great amount of chlorine in plastics; one the other hand, Chinese people prefer food

with strong taste, high-level salt content and much sediments, which leads to the

relatively high chlorine content in MSW. This will further cause high organic and

inorganic chlorine content in MSW incineration fly ash in China, with a total content

reaching as high as 30%. Chlorine, as a volatile and disruptive element, has great

effect upon the treatment and disposal as well as resource utilization of fly ash. Some

disposal specifications explicitly clarify the chlorine concentration of pre-treated fly ash.

211. Currently, the treatment and disposal technologies for MSW incineration fly

ash in China are mainly cement solidification - hazardous wastes landfill disposal

technology, chelate stabilization - sanitary landfill disposal technology, construction

materials’ resource utilization (cement kiln co-disposal) and sintered ceramsite

technology.

212. Table 4-5 shows the daily fly ash production and disposal technologies in

some areas of China.

Table 4-5 The Daily Fly Ash Production and Disposal Technologies in Some Areas

Area Fly Ash Production

t/d

Disposal Technologies

Shanghai 345 2020yearAll according to the danger of waste into the safety landfill. In Shanghai laogang domestic waste landfill

according to hazardous waste landfill standard partition separate fly ash safety landfill.

Dalian 20-30The incineration fly ash stabilized with chemicals is

sanitized for landfill according to the "Domestic Waste Landfill Pollution Control Standard" (GB 16889-2008).

Chongqing 30

The generated slag is used for producing building materials, and solidified/stabilized fly ash enters the

landfill of the hazardous waste for safety landfill. Sanfeng environment is studying the use of dioxin


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detoxification incineration fly ash instead of slag production of asphalt concrete and asphalt pavement.

Beijing 150

Currently, 1/3 of the fly ash is processed by cement kilns in Liulihe cement plant. There is no other disposal

method in Beijing. The fly ash produced in previous years is temporarily stored in eco-island company under

the same group as Beijing Liulihe cement co., ltd of Beijing Jinyu group.

Tianjin 136 Safety landfill and Yiming detoxification and recycling for

ceramsite

Guangzhou 41

Solidified and into the landfill disposal, curing block factory standards to meet the indicators of "Landfill

Pollution Control Standards" (GB16889-2008) and the 2Mpa strength standards of company.

Shenzhen 100 Adopt solidification/stabilization technology to dispose

and curing block is into the landfill.

Wuhan 520 At present, fly ash are used pharmaceutical stabilization,

cement curing process for processing, temporary storage plant.

Zhejiang 45

The main technologies are chemical stabilization, cement curing process. Fly ash safety disposal 2%, sanitary landfill 62%, resource 33%, the rest in the

incineration enterprises temporary storage.

4.4.1 Application Status of MSW Incineration Fly Ash’s Safe Disposal Technology

4.4.1.1 Safe Disposal Technology for Fly Ash

1) Solidification - Hazardous Wastes Landfill Disposal

213. Prior to 2008, fly ash had been listed into National Catalogue of Hazardous

Wastes, whose treatment process must strictly conform to the relevant regulations of

Pollution Control Standards for Hazardous Wastes Landfill (GB 18598-2001): fly ash

generated from MSW incineration must be separately collected and can’t be blended with MSW, incineration sediments and other wastes as well as other hazardous wastes;

the long-term storage of MSW incineration fly ash in its producing place is prohibited,

so is the simple disposal and emission. MSW incineration fly ash must be solidified

and stabilized in its producing place before being transported and the exclusively

airtight transportation tools are required; MSW incineration fly ash must be safely

landfilled. Except from disposing the fly ash with safe landfilling approach, the heavy

metal content from its leach liquid must satisfy the requirement proposed by the

standards.

214. Heavy metals from fly ash are usually solidified through cement solidification

technology, a conventional fly ash treatment approach with broad materials sources,

simple device techniques, low treatment cost, high-level strength of solidified products,

etc. It is actually applied by various construction projects at home and abroad. Recently,


98

Japan as well as European and American countries have generally adopted this

approach as the final disposal technique for poisonous and hazardous wastes. While

conducting the cement solidification, the concentration of fly ash’s leached liquid pollutants must meet the requirements requested by Pollution Control Standards for

Hazardous Wastes Landfill (GB 18598-2001) and then be safely landfilled. Table 4-6

illustrates the leached pollutants concentration limits of fly ash’s cement solidification.

Table 4-6 Leached Pollutants Concentration Limits of Fly Ash’s Cement Solidification

No. Pollutant Item Concentration

Limits mg/L

1 Organic Mercury 0.001

2 Mercury and its Compounds 0.25

3 Plumbum 5

4 Cadmium 0.5

5 Total Chromium 12

6 Hexavalent Chromium 2.5

7 Copper and its Compounds 75

8 Zinc and its Compounds 75

9 Beryllium and its Compounds 0.2

10 Barium and its Compounds 150

11 Nickel and its Compounds 15

12 Arsenic and its Compounds 2.5

13 Inorganic Fluoride 100

14 Cyanide 5

215. However, among cities which have built wastes incineration treatment

facilities, most of them haven’t established any safe landfill plants for hazardous wastes. During “the Tenth Five-year” period, National Plan on the Construction of

Treatment and Disposal Facilities for Medical Waste and Hazardous Waste proposed

by National Development and Reform Commission and State Environmental

Protection Administration, only planned the construction of 30 safe landfill plants for

hazardous wastes. Even cities with safe landfill plants, like Shanghai, Shenzhen, etc.,

all occupy a limited landfilling capacity with a unit landfill capacity’s construction cost of RMB 300yuan/m3. The treatment expense charged when incineration fly ash enters

to hazardous wastes landfill plants is RMB 1000-2000yuan/t (including government

subsidies). Besides, compared with the production amount of other hazardous wastes,

that of incineration fly ash is quite huge. If using all the limited safe landfill plants for

the treatment of incineration fly ash, it will surely affect the landfill disposal capacity for

other hazardous wastes that can be more harmless.

216. Therefore, viewing from the perspective of limited safe landfill plants

resources or the priority of the disposal cost and wastes disposal, safe landfill disposal


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for incineration fly ash is still hardly to be achieved in many cities till now.



2) Chelate Stabilization - Sanitary Landfill Disposal

217. Till 2008, Landfill Pollution Control Standards of Municipal Solid Wastes

(GB16889-2008) issued in China clarified: Treated MSW incineration fly ash and

medical wastes incineration sediments (including fly ash slags) must satisfy the

following prerequisites before entering to MSW landfill plants for separate landfill

disposal: the moisture content less than 30%; the dioxins content less than 3

μg /kg (international toxic equivalent quantities); hazardous concentration of the

leach liquid prepared based on HJ/T 300 less than the limit value prescribed by the

state can be sent to MSW landfill plants for separate landfill. After pre-treatment like

detoxification and stabilization for MSW incineration fly ash, once the leach amount of


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the harmful components exposed to air in the MSW landfill plants doesn’t do any harm to the human body and the environment, i.e., meeting the above-mentioned

prerequisites, then the MSW can be delivered to the MSW landfill plants for disposal.

Compared with solidification - hazardous wastes landfill disposal, chelate stabilization

- sanitary landfill disposal greatly broadens the safe and harmless disposal approaches

for MSW incineration fly ash in China, and lays a solid foundation as well as perfect

preparation for the promotion and construction of MSW incineration plants in China.

218. Table 4-7 shows the pollutant concentration limits of stabilized leach liquid

prescribed by Landfill Pollution Control Standards of Municipal Solid Wastes

(GB16889-2008).

Table 4-7 Pollutant Concentration Limits of Stabilized Leach Liquid Prescribed by

Landfill Pollution Control Standards of Municipal Solid Wastes (GB16889-2008)

No. Pollutant Items Concentration Limits (mg/L)

1 Mercury 0.05

2 Copper 40

3 Zinc 100

4 Plumbum 0.25

5 Cadmium 0.15

6 Beryllium 0.02

7 Barium 25

8 Nickel 0.5

9 Arsenic 0.3

10 Total Chromium 4.5

11 Hexavalent Chromium 1.5

12 Selenium 0.1

219. Meanwhile, in order to guarantee a hazardous component concentration

leached from the MSW incineration fly ash in MSW landfill plants that will not cause

any harm to the surrounding environment, the proportion of MSW incineration fly ash

amount entering to the MSW landfill plants every day can’t exceed 5% of that of the total MSW amount to be landfilled every day.

220. Fly ash entering to the landfill plants after solidification and stabilization is the

main international fly ash treatment approach.


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Figure 4-6 Shenzhen Laohukeng Wastes Incineration Plant

4.4.1.2 Safe and Sustainable Utilization of Fly Ash

1) Resource Utilization for Construction Materials (Cement Kiln Co-disposal)

221. Resource utilization for construction materials of fly ash is dominated by

cement kiln co-disposal. Currently, various national standards, technical specifications

as well as relevant rules and regulations have been issued in China. Solid Wastes

Pollution Control Standards for Cement Kiln Co-disposal, Solid Wastes Technical

Specifications for Cement Kiln Co-disposal and Solid Wastes Environmental

Protection Technical Specifications for Cement Kiln Co-disposal have provided fly

ash’s cement kiln co-disposal with specified management foundation to guarantee the

cement quality as well as prevent and control secondary pollution. Beijing Liulihe

Cement Co., Ltd. has already commenced the time application of fly ash’s cement kiln co-disposal and accumulated certain experience.

Figure 4-7 Beijing Liulihe Cement Co., Ltd.

222. Dealing with fly ash with cement kiln co-disposal technology must conform to

the corresponding requirements proposed by Solid Wastes Pollution Control

Standards for Cement Kiln Co-disposal (GB30485-2013) and Solid Wastes

Environmental Protection Technical Specifications for Cement Kiln Co-disposal

(HJ662).

Limits Specifications of Heavy Metals from Raw Materials in the Kiln:

223. Article 6 (GB30485-2013) stipulates: referential limits of heavy metal content


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from raw materials in the kiln

224. Article 6.1 (GB30485-2013) stipulates: to ensure the heavy metal content from

cement clinkers meets the requirements, heavy metal content from raw materials in

the kiln after calculation should not exceed the referential limits prescribed by Table 4-

7. Heavy metal content from raw materials in the kiln should be calculated in

accordance with Formula 4-1:

� =∑� � +� � + �� 1 −∑� − �

In the formula above:

- feeding period after cement kiln co-disposal of solid wastes, i class heavy

metal content in raw materials, mg/kg;

i - Heavy metal types, named as No. 1, 2, 3, etc.;

j - types of cement kiln co-disposal of solid wastes, named as No. 1, 2, 3, etc.,

including raw materials preparing system, decomposing incinerator, solid wastes

added to the cement kiln system;

- heavy metal content of i type of j class solid wastes flying (ignition base), mg/kg;

- batching proportion of j class solid waste (ignition base) converted to raw

materials, %;

- heavy metal content of i type in the coal ash, mg/kg;

- batching proportion of coal ash converted to raw materials, %;

- heavy metal content of i class in raw materials, during the period of no solid

wastes adding, mg/kg.

Table 4-8 Referential Limits of Heavy Metal Content from Raw Materials in the

Kiln

Heavy Metal Elements Referential Limits (mg/kg)

Arsenic (AS) 28

Plumbum (Pb) 67

Cadmium (Cd) 1.0

Chromium (Cr) 98

Copper (Cu) 65

Nickel (Ni) 66

Zinc (Zn) 360

Manganese (Mn) 384


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225. Article 6.2 (GB30485-2013) stipulates: the determination of feeding volume

after cement kiln co-disposal of solid wastes can also take the maximal heavy metal

adding volume prescribed by Solid Wastes Environmental Protection Technical

Specifications for Cement Kiln Co-disposal (HJ662) for reference.

226. Article 6.6.7 (HJ662) stipulates: the maximal heavy metal adding volume of

materials in the kiln (including regular raw material, fuels and solid wastes) shouldn’t exceed the limits listed in Table 4-8. For heavy metals with the unit of mg/kg-cem, the

maximal adding volume also includes the heavy metals brought by blending materials

while grinding the cement. Table 4-9 shows the maximal heavy metal adding volume

prescribed by Standard HJ662.

Table 4-9 Maximal Heavy Metal Adding Volume

Heavy Metals Unit Maximal Adding

Volume

Hydrargyrum (Hg)

mg/kg-cli

0.23

TI+ Cd+ Pb+15×AS

Thallium + Cadmium + Plumbum + 15×Arsenic (TI+ Cd+ Pb+15×AS)

230

Be+Cr+10×Sn+50Sb+Cu+Mn+Ni+V

Beryllium + Chromium + 10×Stannum + 50×Stibium + Copper + Manganese + Nickel +

Vanadium Be+Cr+10×Sn+50Sb+Cu+Mn+Ni+V

1150

Total Chromium (Cr)

mg/kg-cem

320

Hexavalent Chromium (Cr6+) 10a

Zinc (Zn) 37760

Manganese (Mn) 3350

Nickel (Ni) 640

Molybdenum (Mo) 310

Arsenic (As) 4280

Cadmium (Cd) 40

Plumbum (Pb) 1590

Copper (Cu) 7920

Hydrargyrum (Hg) 4b

Note: a: total chromium added to the kiln materials and hexavalent chromium in the

blending materials; b: mercury added to the blending materials.

Limits Specifications of Heavy Metals from Cement Clinkers:

227. Article 7 (GB30485-2013) stipulates: limits of heavy metal content from

cement clinkers

228. Article 7.1 (GB30485-2013) stipulates: while the cement kiln co-disposal of


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solid wastes is conducted, the produced cement clinker should meet the requirements

of GB/T21372-2008 and its heavy metal content shouldn’t exceed the prescribed limits

in Table 4-10. The monitor of heavy metal content from cement clinkers should be

operated in accordance with the approach prescribed in Appendix B.

Table 4-10 Heavy Metal Content Limits from Cement Clinkers

Heavy Metal Elements Limits (mg/kg)

Arsenic (AS) 40

Plumbum (Pb) 100

Cadmium (Cd) 1.5

Chromium (Cr) 150

Copper (Cu) 100

Nickel (Ni) 100

Zinc (Zn) 500

Manganese (Mn) 600

229. Article 8 (GB30485-2013) stipulates: heavy metal content limits leached from

cement clinkers.

230. Article 8.1 (GB30485-2013) stipulates: while the cement kiln co-disposal of

solid wastes is conducted, the heavy metal content leached from cement clinkers

shouldn’t exceed the prescribed limits in Table 4-11.

231. Article 8.2 (GB30485-2013) stipulates: the test of heavy metal content leached

from cement clinkers can be conducted in accordance with the approaches prescribed

by GB/T30810, among which, the sample preparation should follow Article 5.2 in

GB/T21372-2008.

Table 4-11 Heavy Metal Content Limits Leached from Cement Clinkers

Heavy Metal Elements Limits (mg/kg)

Arsenic (AS) 0.1

Plumbum (Pb) 0.3

Cadmium (Cd) 0.03

Chromium (Cr) 0.2

Copper (Cu) 1.0

Nickel (Ni) 0.2

Zinc (Zn) 1.0

Manganese (Mn) 1.0

Limits Specifications of Chlorine (CI) and Fluorine (F) from Raw Materials in the

Kiln:

232. Article 6.6.8 (HJ662) stipulates: co-disposing corporations should control the


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chlorine and fluorine adding volume in the kiln in accordance with cement’s production techniques to ensure that the cement’s regularity and clinker quality conforms to the national standard. Fluorine content of materials in the kiln shouldn’t exceed 0.5% while that of chlorine shouldn’t exceed 0.04%.

Limits Specifications of Sulphur (S) from Raw Materials in the Kiln:

233. Article 6.6.9 (HJ661) stipulates: co-disposing corporations should control the

sulfur adding volume in the materials. The content of sulfur added through batching

system in the materials and the total organic sulfur content shouldn’t exceed 0.014%; total sulfur added from the high-temperature zone of the kiln head and kiln tail and the

total adding volume of sulfate sulfur added through the batching system shouldn’t exceed 3000mg/kg-cli.

234. However, chlorine content in the fly ash is as high as 10%-25%. Using cement

kiln co-disposal for fly ash’s treatment must dechlorinate the fly ash during the pre -

treatment process and then adopts washing dichlorination in actual application. The

great amount of high saltwater-washing waste water produced should be further

disposed, which increases the treatment difficulty and the treatment cost. In addition,

fly ash’s cement kiln co-disposal technique solidifies heavy metals into the cement

products. But the total heavy metal amount isn’t reduced and there still remains potential harm.

235. Consequently, fly ash’s cement kiln co-disposal producing cement technique

should lay great emphasis on its product quality, standard treatment process and

prevention from secondary pollution, etc.

236. The Shanghai Solid Waste Disposal Center technical team established a 40t/d

wet fly ash pretreatment detoxification industrialization demonstration project based on

wet pretreatment of fly ash heavy metals and chloride ion detoxification results. The

demonstration project mainly includes wet-process pretreatment of fly ash, low

temperature detoxification of dioxin, preparation of ecological cement raw materials by

pretreatment of fly ash, and zero discharge of pretreatment fly ash wastewater, etc..

The results show that the residual chlorine content in the fly ash after the pretreatment

is stable below 0.60%, which meets the resource utilization requirements of cement

kiln and other resources.

237. The Disposal techniques of Dalian Xiaoyetian Cement Co., Ltd include

pretreatment of fly ash washing, cement kiln co-disposal, heavy metal precipitation

process of washing wastewater. After washing, the chlorine content in the raw ash can

be reduced from 20% to 1.5%, and the high temperature generated chlorine-containing

substances are released by the bypass blower in the co-processing stage of the

cement kiln. The heavy metal ions contained in the washing waste water pass through

the inlet waste kiln gas, the use of waste kiln gas CO2 to achieve heavy metal co-


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precipitation, and reduce the pH value of wastewater, the resulting heavy metal

precipitate into the cement kiln for disposal. Material temperature in cement kiln is

higher than 1450 ℃, gas temperature is higher than 1750 ℃, gas residence time in

cement kiln is higher than 5s, which can dispose heavy metals and dioxins efficiently,

total cost of disposal process is expected 800 yuan/ton of fly ash.

2) Sintered Ceramsite Technology

238. One important advantage of high-temperature sintering technology is that the

sintered products from incineration fly ash can achieve resource utilization. In one hand,

the sintered products occupy diverse necessary properties required by construction

aggregates and can be directly used as subgrade materials or for other construction

purpose; one the other hand, they can be used for the pouring of ordinary concrete in

place of natural aggregates and meet relevant requirements for concrete properties.

One more essential advantage of fly ash’s high-temperature sintering treatment is to

solidify heavy metals and dissolve dioxins after high-temperature sintering. Much more

MSW incineration plants at home and abroad adopts high-temperature sintering

technology for the treatment of fly ash to achieve fly ash’s recourse utilization. Figure

4-8 is for sintering fly ash sintering process diagram.

Figure 4-8 Sintering Fly Ash Sintering Process Flow Chart

239. Yet, pure sintered products of incineration fly ash have their own shortcomings

Quality Testing of Fly Ash

Mix Fly Ash and Ceramsite Raw Materials with Certain Ratio

Gra ulatio

Treated Exhaust Emission

High Temperature Calcination for Ceramic Production

Ceramsite Product Performance Testing


107

- inefficient mechanical strength (4.2-6.3 MPa), poor chemical stability after water

immersion and high volatile amount of incineration fly ash during the high-temperature

process (20.1-33.1%). Therefore, before incineration fly ash’s high-temperature

sintering, proper pre-treatment as well as quenching and tempering of additive are

required with the aim of removing chloride and sulfate so as to reduce the volatile

amount during the high-temperature process and improve the sintering properties.

Additives should also be added to strengthen the product’s strength after sintering.

240. Long before 2003, Tsinghua University had conducted deep research on fly

ash’s washing pre-treatment to remove chloride/sulfate, add conditioner, solidify heavy

metals and decompose dioxins in high-temperature, from small test to medium

research. The research results had led scholars in the field of MSW incineration in

China to conduct more deepened and broadened research and application.

241. Tianjin Yiming Environmental Technology Co., Ltd. adopts new high-

temperature sintered ceramsite technology to granulate the fly ash and auxiliary

materials together and send them to the cement kiln for sintering under the

temperature of 1200-1350℃. The fly ash will remain in the kiln for about 30-40 min and

take full advantages of its volatile auxiliaries such as its innate CI salt to volatilize the

heavy metals under the high temperature into fuel gas and force them to be captured

to the secondary fly ash; involatile heavy metals will be solidified into the ceramsite’s mineral crystal lattice after high-temperature chemical reactions so as to reduce both

the total heavy metal amount and leach amount of the ceramsite products. Then,

solidify the collected secondary fly ash for melting and solidification, or recycle heavy

metals, or landfill them after stabilization and solidification to greatly reduce the landfill

amount. Such technology has begun its engineering application.

Figure 4-9 Tianjin Yiming Environmental Technology Co., Ltd.


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3) Plasma Melt Co-disposal

242. The Shanghai Municipal Solid Waste Disposal Center introduced a plasma

gasification facility to conduct an experiment on the melting disposal technology of

MSWI fly ash. The main body of plasma gasification device consists of feed system,

gasifier, two combustion chamber, waste heat boiler, electrostatic precipitator, dry

reaction tower, bag filter, wet scrubber and other components. Plasma gasification

technology uses a plasma torch as the heat source of a gasifier to generate high

intensity heat (about 5500 °C). The plasma in the gasifier is a highly ionized hot gas.

Due to the high temperature and high thermal characteristics of plasma gasification

technology, the organic matter in the waste can be efficiently converted to syngas

(mainly CO and H2) while the inorganic matter can become harmless ash (vitreous

slag).

243. In the process of high temperature melting, the heavy metals in the fly ash are

easy to form a volatile heavy metal chloride with a large amount of chlorine contained

in the fly ash to separation, so that the total heavy metal content in the molten product

is greatly reduced. At the same time, due to the melting of fly ash to produce glass,

melting product will have a dense package performance. In the case of sufficient

melting, the residual heavy metals are tightly packed in the vitreous. According to

relevant research and analysis, the leaching of vitreous body caused by the fly ash

melting is much lower than the TCLP-related leaching standard of the U.S. EPA, and

even meets the Grade 3 standard of groundwater in some cases. Therefore, the glass

melt produced by fly ash can be used as a raw material instead of building materials.

Fl Ash

Plas a Pro essi g De i es

Pretreat e t

Cooli g

Flue Gas Mo itori g S ste

Plas a Treat e t Produ ts


109

Figure 4-10 Shanghai Plasma Co-disposal Flow Chart

4) Asphalt Solidification/Stabilization Co-disposal

244. Chongqing Sanfeng Environment and Chongqing Transportation Research

and Design Institute, Chinese Academy of Sciences and Chongqing-Guizhou CITIC

achieved high efficiency dioxin degradation by the low temperature pyrolysis MSWI fly

ash, and then exploited the strong wrapped characteristics of asphalt concrete to

stabilize heavy metals. fly ash with detoxification dioxin detonated instead of slag

production of asphalt concretes have been applied in some sections of Chongqing-

Guizhou expressway construction of fly ash asphalt concrete pavement demonstration

project.

245. In this project, the mechanism of bitumen-based stabilization of heavy metals

is studied in depth. According to the composition and pollution characteristics of MSWI

fly ash, the feasibility of dioxin detoxification incineration fly ash to replace mineral

powder to produce asphalt concrete and incineration fly ash asphalt pavement is

proposed. The study and research was carried out about migration, transformation and

release of pollutants such as heavy metals and polycyclic aromatic hydrocarbons

(PAHs) in the process of producing asphalt concrete that incineration fly ash instead

of mineral powder, and developed the environmental risk assessment of whole process

on the basis of this study. it can also provide support of environmental safety for fly

ash replacement of mineral powder production of asphalt concrete technology

promotion. Environmental benefits, social benefits and economic benefits of MSWI fly

ash after dioxin detoxification and resource utilization were systematically analyzed.

246. Through the research of physical and chemical characteristics of fly ash, the

study of hydrolysis and digestion process, the study of the properties of the mortar to

determine the mechanism of asphalt-coated fly ash and stabilizing the heavy metals,

it is pointed out that when the addition proportion of fly ash is 2%, the leaching

concentrations of heavy metals in all asphalt concrete samples are lower than those

of drinking Water standard. Through the freeze-thaw splitting experiment and the high-

temperature test, the road performance of the fly ash asphalt mixture is tested and the

pavement plan of fly ash asphalt experimental road is determined.

4.4.2 The Development of and Problems Faced by the Treatment and Disposal of MSW Incineration Fly Ash in China

4.4.2.1 The Development Tendency of the Treatment and Disposal of MSW Incineration Fly Ash in China

247. Viewing from the above-mentioned stage-based progress of the development

of MSW incineration fly ash’s treatment and disposal technology’s application, it’s easy


110

to notice that MSW incineration fly ash is disposed by treatment authorities with

relevant license for the treatment and disposal of hazardous wastes after strict

solidification in accordance with hazardous wastes’ treatment, or be landfilled in divisional MSW sanitary landfill plants after stabilization; till 1 August, 2016, the latest

edition of National Catalogue of Hazardous Wastes (2016 Edition) was carried out,

which newly added Exemption and Management List for Hazardous Wastes. MSW

incineration fly ash can be exempt during the disposal process under the condition:

“meet the requirements prescribed by Article 6.3 of Pollution Control Standards of

MSW Landfill Plants (GB16889-2008) and then enter to the MSW landfill plant for

landfilling; meet the requirements prescribed by Solid Wastes Pollution Control

Standards for Cement Kiln Co-disposal (GB30485-2013) and enter to the cement kiln

for co-disposal.” The exempt content is: “the landfill process doesn’t conform to the management of hazardous wastes; the cement kiln co-disposal process doesn’t conform to the management of hazardous wastes.” While “exempt” can be comprehended as: corporations with no comprehensive business license for

hazardous wastes (such as MSW sanitary landfill plants, cement producing

corporations, etc.) can receive fly ash treatment observing the exempt conditions. The

implementation of this policy broadens the fly ash treatment approaches, improves the

fly ash treatment efficiency and properly reduces the fly ash treatment cost.

248. It can be seen that the treatment technology of MSW incineration fly ash in

China is still on its way of being updated and broadened. It also requires the experts

in this field’s passion and persistent exploration as well as the strong economic and political support from the government.

4.4.2.2 Disposal/Re-utilization Ability Status of Current Treatment Facilities

249. According to statistics, the waste incineration amount in 2015 was 61 million

tons while the fly ash generation amount had reached as high as 3.95 million tons.

Along with the conduct of “the 13th Five-year Plan”, the targeted incineration rate in China will be increased from 34% currently to 50% in 2020. Correspondingly, the fly

ash’s generation amount will be more and more. The primary treatment approach for

incineration fly ash in China is stabilization - sanitary landfill disposal with resource

utilization gradually developing as fly ash’s sustainable disposal approach to ease certain fly ash landfill pressure.

1) Stabilization - Sanitary Landfill Disposal

250. Based on existing rules and regulations, untreated fly ash must be disposed

in hazardous wastes landfill plants. It can be seen from Figure 4-11 that the hazardous

wastes landfill capacity is only 50% of that of fly ash generation amount, far behind the

disposal demands of the rapidly developing fly ash amount.


111

Figure 4-11 Relation Between Fly Ash Generation Amount and Hazardous

Wastes Landfill Capacity

251. In accordance with Pollution Control Standards of MSW Landfill Plants

(GB16889-2008), once the fly ash is solidified and stabilized, it can then enter to

divisional MSW landfill plants for landfilling. Analyzing from Figure 4-12, the landfill

capacity of MSW landfill plants is far beyond the fly ash generation amount. However,

how many MSW sanitary landfill plants can achieve divisional landfill? Indeed, not all

existing sanitary landfill plants are suitable for receiving fly ash treatment. Therefore,

the incineration plants should make clear investigation and select suitable fly ash

treatment approaches while establishing a project.

Figure 4-12 Relation Between Fly Ash Generation Amount and MSW

Landfill Capacity

2) Cement Kiln Co-disposal

252. Beijing Jinyu Environmental Technology Co., Ltd. possesses the first waste


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incineration fly ash disposal line at home, together with two 2,000 tons/day cement

clinkers production lines. Currently, it has established a production line of waste

incineration fly ash disposal based on 2#cement kiln and takes pre-treated fly ash sent

to the cement kiln as part of the raw materials to be calcined into cement clinkers so

as to achieve harmless disposal for waste incineration fly ash with an existing disposal

scale of 9,600 tons/year.

253. Jinyu Environmental plans to expand the production line of existing waste

incineration fly ash disposal into a new one with a scale of 30,000 tons/year; meanwhile,

it will build a new production line of waste incineration fly ash disposal based on its

1#cement kiln with a new fly ash disposal scale of 40,000 tons/year; the fly ash disposal

technique of the expanded and the newly-established production line is consistent with

that of the existing one. Upon its completion, the total fly ash disposal scale of Jinyu

Environmental will reach 70,000 tons/year.

254. The above-mentioned fly ash’s cement kiln co-disposal don’t need to apply the hazardous waste business license anymore, which has improved the development

and promotion of fly ash’s cement kiln co-disposal’s engineering application. In 2015, the national cement production amount was about 2.4 billion tons and the admixture

fly ash amount during fly ash’s cement kiln co-disposal process shouldn’t exceed 3% of that of the raw materials amount. If there are 10% cement corporations co-disposing

fly ash all together, the treatable fly ash amount will be quite considerable. However,

both the product quality and pollutant content should be strictly monitored and

controlled to avoid any harm to the ecological environment and human healthy caused

by secondary pollution.

Figure 4-13 Beijing Building Materials Group

3) Sintered Caramite Technology

255. The caramite production of high-temperature sintered caramite produced by

waste incineration fly ash through the demonstration project carried out by Tianjin

Yiming Environmental Technology Co., Ltd. is about 125,000 tons/year. Calculated by


113

the fly ash admixture proportion of 40%, this production line of waste incineration fly

ash’s high-temperature sintered caramite can utilize and dispose about 50,000 tons of

fly ash annually. While realizing fly ash’s harmlessness, this technology also achieves its reutilization.

256. To conclude, stabilization - sanitary landfill disposal, as the main incineration

fly ash treatment approach in China, can perfectly satisfy the demands in the aspect

of its treatment capacity at present. However, with the gradual decreasing of the

storage capacity, the site-selection is much more difficult and the landfill treatment

pressure gradually emerges as well. On the other hand, fly ash landfill disposal has its

own shortcomings, such as poor heavy metals stabilization effect, undivided landfill,

unimproved matching facilities, etc., leading to high-level environmental risks. Cement

kiln co-disposal and sintered caramite technology can act as the beneficial supplement

for the fly ash landfill treatment, which will not only share the fly ash landfill pressure,

but also achieve the harmlessness and resource utilization of fly ash, with high

economic and environmental benefits. They can be promoted and implemented as

essential technologies for fly ash’s safe and sustainable utilization.

4.4.2.3 Problems Face by the Treatment and Disposal of MSW Incineration Fly Ash in China

257. The development and regulations as well as policies of waste incineration fly

ash’s treatment and disposal in China still faces with the difficulties of innovation and improvement that needed to be addressed.

1) Limited Disposal Technology

258. For resource utilization of MSW incineration fly ash, cement kiln co-disposal

and sintered caramite technology are the two that China has actual application practice

while other resource utilization and treatment technology that haven’t been developed and applied. New technologies are still required to be explored to strengthen the MSW

incineration treatment in China.

2) Unimproved Technical Normative System

259. It can be said that China hasn’t established any systematic normative system for the treatment and disposal of waste incineration fly ash. Its safe disposal and

resource utilization process are mainly implemented and managed in accordance with

the hazardous wastes management approaches and technical specifications. For

example, in 2008, the standards required to be followed as the reference for fly ash

landfill include Pollution Control Standards for Hazardous Wastes Landfill (GB 18598-

2001), Landfill Pollution Control Standards of Municipal Solid Wastes (GB16889-2008).

Then, in 2013, Solid Wastes Pollution Control Standards for Cement Kiln Co-disposal


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(GB 30485-2013), Solid Wastes Technical Specifications for Cement Kiln Co-disposal

(GB 30760-2014) and Solid Wastes Environmental Protection Technical Specifications

for Cement Kiln Co-disposal (HJ/T 662-2013) were carried out to prescribe the

operational technology and pollutants discharge limits of fly ash’s cement kiln co -

disposal.

260. For other fly ash’s disposal or resource utilization technologies (such as sintered caramite, sintered light aggregates for constructions, etc.), there haven’t been any relevant rule, regulations, standards and specifications issued, let along relevant

specification requirements on the heavy metal content and that from the leached liquid

of new technology’s resource utilized products. Since fly ash is listed as hazardous

wastes, improved technical standard system is the guarantee for its safe and normative

treatment and regulations.

3) Loose Regulations on the Treatment and Disposal Process

261. Management of Hazardous Wastes Duplicated Form (Order No.5 issued by

State Environmental Protection Administration) stipulates the application and using

process, filling and preservation requirements as well as supervision demands of the

duplicated form. Unit Management Plans’ Formulating Guidance on the Generation of

Hazardous Wastes (Announcement No.7 in 2016 issued by Ministry of Environmental

Protection) claims, MSW incineration plants that will produce fly ash should regularly

formulate and report its Hazardous Wastes’ Management Plan. Basic information such

as the annual production amount of fly ash and the mode, facility conditions, quantity,

etc. during the management process such as preservation, transferring, disposal and

utilization in accordance with the planned MSW amount to be disposed.

262. Though there are strict requirements from the above-mentioned Management

Plan and Guidance, the actual implementation process is still hard to achieve

sometimes. Investigation shows that though the waste’s components are complicated and the fly ash volatility is relatively huge, most incineration plants still adopt

monotonous mode, fixed stabilizer ratio for solidification and stabilization treatment.

Such approaches will only lead to poor heavy metal stabilization effect and increase

the heavy metals’ leach danger; some fly ash is not landfilled via divisional landfill in

the landfill plant, which will also increase the leach danger of heavy metals and other

ions and is a great safety problem.

263. The main reason for the existence of the above problems proves to be

monitoring. Currently, the government strictly governs the first pollution of fuel gas

discharge in waste incineration plants, but there no special supervision or control

standards of the fly ash treatment process and the possible secondary pollution.


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4) Poor Economic Basis

264. It is well-known that the waste incineration treatment expense is relatively high

all over the world while the high expense is beneficial for the control of pollution

produced during the incineration process. In terms of the statistical data issued by the

World Bank, the incineration expense for every ton of wastes was 150 dollars (RMB

1041.66yuan) on average while that in Holland was 160 euros (RMB 1,184yuan); in

Germany, 200 euros (RMB 1,480yuan). However, the bidding price for MSW

incineration treatment was generally RMB 60yuan~80yuan/ton. The lower bidding

price could even reach RMB 26.5yuan/ton, or even RMB 18yuan/ton at the bottom line.

During the project-establishing, tendering and bidding stage of the waste incineration

project, the contractor didn’t spare exclusive treatment expenses targeted at fly ash

disposal and therefore the fly ash’s treatment and disposal lack the necessary economic basis. Insufficient considerations on the fly ash’s outlet and the actual expenses will mislead the incineration plants to neglect the technical innovation of fly

ash’s treatment and disposal.

4.5 Summary

265. Waste incineration fly ash’s treatment and disposal technologies mainly include solidification - hazardous wastes landfill disposal, stabilization - sanitary landfill

plants disposal, acidic extraction of heavy metals, melting and solidification, etc.;

266. Since 2008, the treatment and disposal technology of incineration fly ash in

China has changed significantly. Before 2008, the mainly fly ash disposal approach

was solidification - hazardous wastes landfill disposal while after 2008, the primary

disposal has become stabilization - sanitary landfill disposal, cement kiln co-disposal

and sintered caramite technology, etc. Especially the implementation of the latest

National Catalogue of Hazardous Wastes (2016 Edition) newly added Exemption and

Management List for Hazardous Wastes in 2016 had broadened the space for fly ash’s normative and safe disposal. While complying with the exempt conditions, fly ash can

be disposed in corporations with no business license for hazardous wastes’ comprehensive management.

267. The normative regulation of incineration fly ash’s treatment and disposal in China still has a long way to go, which requires technical innovation, improved

standard system, mature policies and regulations as well as strict supervisory process.

TA-8963 PRC Final Report Chapter V

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CHAPTER5 EXISTING POLICIES AND REGULATIONS

SYSTEM IN CHINA

5.1 Regulations on MSWI Fly Ash Management in PRC

5.1.1 State Regulations

268. In accordance with existing regulations in China, MSW incineration fly ash

belongs to hazardous waste and should be brought into the national and local solid

waste management system for further environmentally sound management.

5.1.1.1 Environmental Protection Law

269. Environmental Protection Law of the People’s Republic of China, the basic

environmental management law in China, was officially adopted and implemented at

the 11th Meeting of the Standing Committee of the Seventh National People's

Congress on December 26, 1989 and amended at the 8th Meeting of the Standing

Committee of the Twelfth National People’s Congress on April 24, 2014. The revised

version finally came into force on 1 January, 2015.

270. Environmental Protection Law is composed of 7 chapters and 70 articles,

including the basic principles of national environmental protection and rules related to

the supervision and administration of environmental protection, environmental

protection and the improvement of environmental quality, prevention and control of

pollution, information disclosure and public involvement, etc. it also makes provision

for the legal liability caused by environmental pollution. Besides, targeted at the

prevention and control of solid waste pollution, Chapter IV “Prevention and Control of

Environmental Pollution and Other Public Hazards” stipulates: “Article 42 Enterprises

and institutions and other producers and operators that discharge pollutants shall take

measures to prevent and control pollution and other hazards caused to the

environment by waste gas, waste water, waste residues, medical waste, dust,

malodorous gases, radioactive substances, noise, vibration and optical and

electromagnetic radiation generated in the course of production, construction or other

activities”; “Enterprises and public institutions that discharge pollutants shall establish


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an environmental protection responsibility system and specify the responsibilities of

the persons-in-charge of the entities and the relevant personnel”; “It is prohibited to

illegally discharge pollutants by means of concealed conduits, seepage well, seepage

pit, perfusion or alteration and forgery of monitoring data or abnormal operation of

pollution prevention and control installations to avoid supervision.”

271. In terms of the provisions of this article, the liability subject responsible for the

prevention and control of fly ash, the dust generated and collected for treatment during

MSW incineration process, turns to be “enterprises and institutions and other

producers and operators that discharge pollutants” , i.e., MSW incineration plants and

their belong companies that produce incineration fly ash. Meanwhile, the provisions of

this article also clarify that perfusion—a widely-used technology for the disposal of

hazardous waste—is “illegal discharge” technology in China and is strictly prohibited.

272. Clauses related to the environmental management of solid waste and

hazardous waste (including MSW incineration fly ash) prescribed in Environmental

Protection Law also include the following contents:

273. “Article 49 No solid waste and sewage that fail to meet the agricultural

standards and environmental protection standards shall be applied to the farmland.

Measures shall be taken for application of pesticide, fertilizer and other agricultural

inputs and irrigation to prevent the pollution of heavy metal and other hazardous

substances.” Based on this provision, MSW incineration fly ash used for the

improvement of farmland soil is prohibited.

274. “Article 51 The people's governments at all levels shall comprehensively

arrange the sewage treatment installations and ancillary pipe network for urban and

rural construction, environmental sanitation installations for collection, transportation

and disposal of solid waste, installations and sites for centralized treatment of

hazardous waste as well as other public environmental protection installations, and

make sure the normal operation of such installations.” In accordance with this provision,

the installations for the disposal of MSW incineration fly ash should be

comprehensively arranged by the local government. However, no specific level of the

people’s government in charge is stipulated. Therefore, the overall arrangement and

construction should be conducts based on the local condition, which should also


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include cross-provincial transportation and disposal of MSW incineration fly ash.

275. “Article 36 The State shall encourage and instruct the citizens, legal persons

and other organizations to use environment-friendly products and recycled products in

order to reduce the generation of waste.” This provision shows that the promotion and

application of comprehensively used MSW incineration fly ash products should be

encouraged under the precondition of “benefiting environmental protection”.

276. In addition to the above-mentioned provisions, Environmental Protection Law

also delivers principle regulations related to the installations construction involved in

MSW incineration fly ash’s disposal, the operation and management of relevant

“environmental impact assessment”, “pollutant discharge standards”, “fees for

pollutant discharge and environmental protection tax”, “pollution discharge license”,

etc.

5.1.1.2 Law on Prevention of Environmental Pollution Caused by Solid Waste

277. Law of the People's Republic of China on Prevention of Environmental

Pollution Caused by Solid Waste is the basic law in China related to solid waste’

environmental management with Environmental Protection Law as its high-level law.

Law on Prevention of Environmental Pollution Caused by Solid Waste was approved

at the 16th Meeting of the Standing Committee of the Eighth National People's

Congress on October 30, 1995, to be effective on April 1, 1996; the new version was

amended at the 13th Meeting of the Standing Committee of the Tenth National

People's Congress on December 29, 2004, to be effective on April 1, 2005; in

accordance with Decisions on the Amendment of 12 Laws Including Cultural Relics

Protection Law of the People's Republic of China revised at the Third Meeting of the

Standing Committee of the Twelfth National People's Congress on June 29, 2013 for

the first time and the second amendment was conducted at the 14th Meeting of the

Standing Committee of the Twelfth National People's Congress on April 24, 2015

based on Decisions on the Amendment of 7 Laws Including Port Law of the People's

Republic of China with the third amendment conducted at the 24th Meeting of the

Standing Committee of the Twelfth National People's Congress on November 7, 2016

in terms of Decisions on the Amendment of 12 Laws Including Foreign Trade Law of

the People's Republic of China.


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278. As the basic law in China related to the environmental management of solid

waste, Law on Prevention of Environmental Pollution Caused by Solid Waste

stipulates the basic principles for the management of solid waste, liability subject for

the prevention and control of pollution caused by solid waste and the liability subject

for supervision and administration and provides provisions related to the supervision

and administration on the prevention and control of pollution caused by solid waste,

prevention and control of pollution caused by solid waste, prevention and control of

industrial solid waste and the pollution caused by MSW, etc. It also offers special

stipulations on the prevention and control of environmental pollution caused by

hazardous waste.

(1) General Principles on the Management of Solid Waste

279. Law on Prevention of Environmental Pollution Caused by Solid Waste clarifies

the general principles related to the management of solid waste, i.e., “Article 3 The

State shall, in preventing and controlling environmental pollution by solid waste,

implement the principles of reducing the discharge volume and hazardousness of solid

waste, fully and rationally utilizing solid waste, and making it hazardless through

treatment as well as promoting clean production and recyclable economic

development.” In accordance with this principle, the environmental management of

MSW incineration fly ash should conform to the technical route in the sequence of

reducing production volume, promoting comprehensive utilization and harmless

disposal.

(2) Liability Subject for the Prevention and Control as well as Supervision and

administration of Pollution Caused by Solid Waste

280. When it comes to the liability subject responsible for the prevention and

control of pollution caused by MSW incineration fly ash, Law on Prevention of

Environmental Pollution Caused by Solid Waste stipulates, “Article 5 The State shall,

in preventing and controlling environmental pollution by solid waste, implement the

principle of legal accountability by the person causing pollution. The producers, sellers,

importers and users of the products shall bear liability according to law for preventing

and controlling environmental pollution by the solid waste generated from their

products.” MSW incineration fly ash is caused by MSW disposal while MSW is caused


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via the residents’ (consumers’) commodities (products) using process. Consequently,

based on the former stipulation, the liability subject responsible for the prevention and

control of pollution caused by MSW incineration fly ash should be the MSW

generators—the residents (consumers). In view of consumers’ dispersiveness, such

liability always comes to the government’s rescue.

281. As for management liability of MSW incineration fly ash, Law on Prevention

of Environmental Pollution Caused by Solid Waste makes the following stipulation,

“Article 10 The competent administrative department of environmental protection

under the State Council shall conduct unified supervision and administration of the

prevention and control of environmental pollution by solid waste throughout the country.

The relevant departments under the State Council shall be responsible for supervision

and administration of the prevention and control of environmental pollution by solid

waste within their respective functions and responsibilities. The competent

administrative departments of environmental protection under the local people's

governments at or above the county level shall conduct unified supervision and

administrative of the prevention and control of environmental pollution by solid waste

within their jurisdictions. The relevant departments of local people's governments at or

above the county level shall be responsible for supervision and administration of the

prevention and control of environmental pollution by solid waste within their respective

functions and responsibilities. The competent administrative department of

construction under the State Council and the competent administrative departments of

environmental sanitation under the local people's governments at or above the county

level shall be responsible for supervision and administration with regard to cleaning up,

collection, storage, transportation and treatment of house refuse.” It can be seen that

the liability subject responsible for the prevention and control of environmental pollution

by MSW incineration fly ash should be the competent administrative departments of

environmental protection; since MSW incineration fly ash is derivatives caused by

MSW disposal, the administrative departments in charge of its disposal installations’

construction and operation should be the competent administrative departments of

environmental sanitation.

(3) Job Description of the Administrative Departments of Environmental

Protection


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282. In terms of this provision, Law on Prevention of Environmental Pollution

Caused by Solid Waste stipulates the main responsibilities of the administrative

departments of environmental protection for the management of solid waste, including:

a) Enact National Technical Norms for Preventing and Controlling

Environmental Pollution by Solid Waste

283. “Article 11 The competent administrative department of environmental

protection under the State Council shall, jointly with relevant competent administrative

departments under the State Council, enact national technical norms for preventing

and controlling environmental pollution by solid waste according to the national

environmental quality standards and economic and technical conditions of the State.”

Till now, enacted and implemented technical norms for preventing and controlling

environmental pollution by MSW incineration fly ash includes Standard for Pollution

Control on MSW Incineration (GB 18485-2014), Standard for Pollution Control on

MSW Landfill (GB 18485-2014) (GB16889-2008), Standard for Pollution Control on

the Security Landfill Site for Hazardous Waste (GB18598-2001) and Standard for

Pollution Control on Co-processing of Solid Waste in Cement Kiln (GB30485-2013).

b) Examine and Approve as well as Inspect and Accept the Environmental

Effect Evaluation Report

284. “Article 13 Construction of projects which discharge solid waste and of

projects for storage, utilization and treatment of solid waste shall be conducted

environmental effect evaluation according to law and be in compliance with the

relevant provisions of the State concerning the administration of environmental

protection in respect of construction projects.”

285. “Article 14 The necessary supporting installations for the prevention and

control of environmental pollution by solid waste specified in the statement of the effect

of the construction project shall be designed, built and put into operation

simultaneously with the main part of the project. The construction project shall be put

into production or use, only after the installations for the prevention and control of

environmental pollution by solid waste are examined and considered up to standards

by the competent administrative department of environmental protection that examined


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and approved the statement of environmental effect. The installations for the

prevention and control of environmental pollution by solid waste shall be checked and

accepted at the same time as the main part of the project is checked and accepted.”

286. Law of the People’s Republic of China on Environmental Impact Assessment

was adopted at the 30th Meeting of the Standing Committee of the Ninth National

People’s Congress on October 28, 2002, to be effective on September 1, 2003, and

was revised at the 21th Meeting of the Standing Committee of the Ninth National

People’s Congress on July 2, 2016.

287. The State Environmental Protection Administration promulgated Management

Regulations for Checking and Accepting Completed Installations of Environmental

Protection of Construction Projects (Order No. 13 of the State Environmental

Protection Administration), to be effective on February 1, 2002, which was revised via

Order No. 16 of the State Environmental Protection Administration on December 22,

2010.

c) Enact National Catalogue of Hazardous Waste and Methods for Identifying

and Distinguishing

288. “Article 51 The competent administrative department of environmental

protection under the State Council shall, jointly with other relevant departments under

the State Council, formulate a national catalogue of hazardous waste, lay down unified

criteria and methods for identifying and distinguishing hazardous waste.” On June 14,

2016, the Ministry of Environmental Protection, National Development and Reform

Commission and Ministry of Public Security jointly promulgated the edition of National

Catalogue of Hazardous Waste (Order No. 39 of the Ministry of Environmental

Protection), which was put in force on August 1, 2016. The Ministry of Environmental

Protection had promulgated and implemented Identification Standards for Hazardous

Waste (GB5085.1-.7-2007) with 7 standards included since 2007. These standards

are under amendment currently.

d) Organize Units to Enact Plans for Administration of Hazardous Waste and

Accept Reports


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289. “Article 53 Units generating hazardous waste shall enact plans for

administration of hazardous waste according to relevant provisions of the State, and

report relevant materials concerning category, discharge volume, flow direction,

storage and treatment of hazardous waste to the competent administrative

departments of environmental protection under the local people's governments at or

above the county level.”

e) Assign Treating Units

290. “Article 55 Units discharging hazardous waste shall treat hazardous waste in

accordance with relevant provisions of the State but not dump or pile up it without

authorization; otherwise, the competent administrative department of environmental

protection under the local people's government at or above the county level shall order

them to set it right within a specified period of time. If a unit fails to treat the waste

within the specified period of time, or if it has done it but not in conformity with the

relevant provisions of the State, the competent administrative department of

environmental protection under the local people's government at or above the county

level shall assign other units to treat the waste in accordance with relevant State

regulations, and, the units discharging hazardous waste shall bear the costs of

treatment.”

f) Enact Business License for the Treatment of Hazardous Waste

291. “Article 57 Units engaging in collection, storage and treatment of hazardous

waste shall apply to the competent administrative department of environmental

protection under the people's government at or above the county level for the business

license; the units engaging in utilizing hazardous waste shall apply to the competent

administrative department of environmental protection under the State Council or such

departments under the people's governments of provinces, autonomous regions and

municipalities directly under the Central Government for the business license. Specific

measures for the administration thereof shall be prescribed by the State Council.” The

State Council promulgated on Measures for the Administration of Permit for Operation

of Dangerous Waste May 30, 2004, which was implemented on July 1, 2014; this act

was further amended on December 7, 2013 and February 6, 2016 respectively.


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g) Organize Units to Fill in Duplicate Forms for Transfer of Hazardous Waste

and Submit Transfer Application

292. “Article 59 Whoever transfers hazardous waste, shall, according to relevant

provisions of the State, fill in duplicate forms for transfer of hazardous waste and

submit application to the competent administrative department of environmental

protection under the people's governments at or above the municipal level in the places

where the hazardous waste is to be moved out. The competent administrative

department of environmental protection under the people's government at or above

municipal level in the region where the hazardous waste is to be moved out shall, after

consulting with and being consented by the competent administrative department of

environmental protection under the people's government at or above municipal level

in the region where the hazardous waste is to be moved in, approve the transportation

of such hazardous waste out. Transport shall not be conducted without approval.” On

June 22, 1999, the former State Environmental Protection Administration promulgated

Management of Hazardous Waste Duplicated Form (Order No.5 of the State

Environmental Protection Administration), which came into force on October 1, 1999.

h) Inspect Emergence Measures

293. “Article 62 Units discharging, collecting, storing, transporting, utilizing or

treating hazardous waste shall work out emergency and protection measures to be

adopted in case of accident, and report such to the competent administrative

department of environmental protection under the local people's government at or

above the county level, which shall conduct inspection, for the record.”

(4) Job Description of the Administrative Departments of Environmental

Sanitation

294. Law on Prevention of Environmental Pollution Caused by Solid Waste

provides stipulations related to the main responsibilities of MSW management for the

administrative departments of environmental sanitation, including:

a) Enact National Standards for Environmental Sanitation

295. “Article 41 Urban house refuse shall be cleaned, collected, transported and


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treated in compliance with the provisions concerning environmental protection and

environmental sanitation administration of the State, thus prevent from environmental

pollution.”

296. “Article 44 Installations and sites for treatment of house refuse shall be built

in compliance with the standards for environmental protection and environmental

sanitation prescribed by the competent administrative department of environmental

protection under the State Council and the competent administrative department of

construction under the State Council.”

297. Ministry of Housing and Urban-Rural Development enacted the industry

standards Operation and Supervision Standards for MSW Incineration Plants

(CJJ/T212-2015) on February 10, 2015, which provided specific stipulations on the

inside management of MSW incineration fly ash in the MSW incineration plants.

298. Ministry of Housing and Urban-Rural Development enacted the national

standards Technical Specifications for MSW Sanitary Landfill Treatment (GB50869-

2013) on August 8, 2013, which provided specific stipulations on the construction and

operation of MSW incineration landfill sites. However, such standard didn’t cover

specific technical requirements for the pre-treatment of MSW incineration fly ash so as

to satisfy the standards of entering MSW landfill sites.

299. So far, the competent administrative departments of construction under the

State Council haven’t promulgated any standards about the construction contents of

recycling MSW incineration fly ash.

b) Organize MSW Treatment

300. “Article 39 The competent administrative departments of environmental

sanitation under the local people's government at or above the county level shall

organize cleaning, collection, transportation and treatment of urban house refuse, and

may select the units satisfying relevant conditions to engage in cleaning, collection,

transportation and disposal of house refuse through the forms such as inviting tender.”

In accordance with this provision, the construction and operation of MSW incineration

fly ash’s disposing and utilizing installations should be organized by the competent


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administrative departments of environmental sanitation.

(5) Liability of the Units Generating MSW Incineration Fly Ash

a) Pollution Control

301. “Article 16 Units and individuals that discharge solid waste shall adopt

measures to prevent or reduce environmental pollution by solid waste.”






b) Report of Plans for Administration of Hazardous Waste for the Record

303. “Units generating hazardous waste shall enact plans for administration of

hazardous waste according to relevant provisions of the State, and report relevant

materials concerning category, discharge volume, flow direction, storage and

treatment of hazardous waste to the competent administrative departments of

environmental protection under the local people's governments at or above the county

level. The plans for administration of hazardous waste as mentioned above shall

include the measures for reducing the discharge volume and hazardousness of

hazardous waste and measures for storage, utilization and treatment of hazardous

waste. The plans for administration of hazardous waste shall be reported to the

competent administrative departments of environmental protection under the local

people's governments at or above the county level in the places where the units

discharge hazardous waste for the record. If the reported matters or contents of plans

for administration of hazardous waste as prescribed in this Article have major changes,

they shall be reported without delay.”

c) Punishment by Law

304. “Article 55 Units discharging hazardous waste shall treat hazardous waste in

accordance with relevant provisions of the State but not dump or pile up it without


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authorization.”

(6) Liability of the Units Responsible for the Treatment and Disposal of MSW


a) Pollution Control

305. “Article 17 Units and individuals that collect, store, transport, utilize or treat

solid waste shall take measures to prevent the scattering, running off, leaking and

seeping of solid waste, as well as other measures against environmental pollution; it

shall not be allowed to dump, pile up, discard or let drop solid waste without

authorization. All units and individuals shall be prohibited to dump or pile up solid waste

to rivers, lakes, canals, channels, reservoirs and the bottomlands, banks and slopes

below the highest water lines of such sites, and other sites that are prohibited dumping

and piling up castoffs by laws and regulations.” According to Interpretation of the

Supreme People's Court and Supreme People’s Procuratorate on Certain Issues

Concerning the Handling of Criminal Cases Related to Environmental Pollution (No.

29 Fashi [2016]) promulgated on December 23, 2016 and implemented on January 1,

2017, once involved to hazardous waste, the above-mentioned actions will be

regarded as “causing severe environmental pollution”, “should be convicted and

punished in terms of offence of environmental pollution”.

306. “Article 21 Administration and maintenance of installations, equipments and

places for collection, storage, transportation and treatment of solid waste shall be

improved so as to ensure their normal operation and function.”

307. “Article 41 Urban house refuse shall be cleaned, collected, transported and

treated in compliance with the provisions concerning environmental protection and

environmental sanitation administration of the State, thus prevent from environmental

pollution.”

308. “Article 45 Substances reclaimed from house refuse shall be used in

accordance with the usage or standards as prescribed by the State but not be used for

producing the products harmful for human heath.”

309. “Article 58 Hazardous waste shall be collected and stored separately


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according to their different characteristics. It shall be forbidden to collect, store,

transport and treat mixed hazardous waste of incompatible nature that have not

undergone safety treatment.”

310. “Article 60 Whoever transports hazardous waste shall adopt measures for

the prevention and control of environmental pollution and observe provisions of the

State concerning the control of transportation of hazardous goods.”






b) Apply for Business License of Hazardous Waste

312. “Article 57 Units engaging in collection, storage and treatment of hazardous

waste shall apply to the competent administrative department of environmental

protection under the people's government at or above the county level for the business

license; the units engaging in utilizing hazardous waste shall apply to the competent

administrative department of environmental protection under the State Council or such

departments under the people's governments of provinces, autonomous regions and

municipalities directly under the Central Government for the business license. Specific

measures for the administration thereof shall be prescribed by the State Council.”

According to National Catalogue of Hazardous Waste and Appendix Exemption and

Management List for Hazardous Waste promulgated on June 14, 2016 and

implemented on August 1, 2016, MSW incineration fly ash will be exempt while

entering to the MSW landfill sites for disposal in accordance with relevant standards,

which means that no business license of hazardous waste is required.

c) Fill in Duplicate Forms for Transfer of Hazardous Waste

313. “Article 59 Whoever transfers hazardous waste, shall, according to relevant

provisions of the State, fill in duplicate forms for transfer of hazardous waste and

submit application to the competent administrative department of environmental


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protection under the people's governments at or above the municipal level in the places

where the hazardous waste is to be moved out. The competent administrative

department of environmental protection under the people's government at or above

municipal level in the region where the hazardous waste is to be moved out shall, after

consulting with and being consented by the competent administrative department of

environmental protection under the people's government at or above municipal level

in the region where the hazardous waste is to be moved in, approve the transportation

of such hazardous waste out. Transport shall not be conducted without approval.”

(7) Qualitative Classification of MSW Incineration Fly Ash

314. a) “Article 88” “(3) House refuse shall mean solid waste discharged from

everyday life or from services provided to everyday life as well as the solid waste that

is regarded as house refuse under laws and administrative rules and regulations.”

Judging from this, MSW incineration fly ash should be classified and managed as MSW.

315. b) “Article 88” “(4) Hazardous waste shall mean waste that is dangerous and

is included in the national list of hazardous waste or identified as such according to the

criteria and methods of identification for hazardous waste as prescribed by the State.”

316. In accordance with “772-002-18 MSW incineration fly ash” from “HW18

incineration disposal of sediments” prescribed by National Catalogue of Hazardous

Waste (Order No. 39 (2016) of Ministry of Environmental Protection, National

Development and Reform Commission and Ministry of Public Security), MSW belongs

to hazardous waste and its management should be conducted in terms of the

management requirements for hazardous waste.

5.1.1.3 Circular Economy Promotion Law

317. Circular Economy Promotion Law of the People’s Republic of China was

approved at the 4th Meeting of the Standing Committee of the 11th National People’s

Congress on August 29, 2008 and implemented on January 1, 2009.

318. Circular Economy Promotion Law clarifies the purpose of this law’s

formulation—“for the purpose of facilitating circular economy, raising resources

utilization rate, protecting and improving environment and realizing sustainable


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development.” Meanwhile, “Resource recovery herein means the direct use of waste

as raw material, or waste regeneration” is also clarified. Consequently, comprehensive

utilization (regeneration) of MSW incineration fly ash should comply with relevant

stipulations prescribed by Circular Economy Promotion Law.

319. The following two items from Circular Economy Promotion Law involves MSW

incineration fly ash.

a) Avoid Re-pollution

320. “Article 4”, “In the process of waste recycling and resource recovery, efforts

shall be made to guarantee production safety, ensure the quality of products meets

standards provided by the State, and avoid re-pollution.” Based on this provision, the

producing and using of products related to comprehensive utilization (regeneration) of

MSW incineration fly ash should avoid re-pollution.

b) Formulate Resource Recovery Standards

321. “Article 17 The standardization department under the State Council shall

establish a sound circular economy standard system together with the general

administration for promoting circular economy and relevant departments for

environmental protection under the State Council, and formulate and improve

standards on energy-saving, water-saving, material-saving, waste recycling and

resource recovery.” Comprehensive utilization (regeneration) of MSW incineration fly

ash is mainly used for producing construction materials. So far, relevant departments

have formulated and implemented environmental protection standards on the process

control and production quality of using solid waste to produce cement (cement kiln co-

processing). However, standards related to using solid waste to produce other

construction materials is insufficient. Likewise, standard circular economy system

hasn’t been established till now.

5.1.1.4 Criminal Law

322. The Criminal Law of the People's Republic of China was passed on the

Second Session of the Fifth National People's Congress on July 1, 1979 and was

revised at the Fifth Session of the Eighth National People's Congress on March 14,


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1997. It has successively been amended or revised by the Amendment to the Criminal

Law of the People's Republic of China (release date: December 25, 1999; date of

enforcement: December 25, 1999), Amendment (II) to the Criminal Law of the People's

Republic of China (release date: August 31, 2001; date of enforcement: August 31,

2001), Amendment (III) to the Criminal Law of the People's Republic of China (release

date: December 29, 2001; date of enforcement: December 29, 2001), Amendment

(IV) to the Criminal Law of the People's Republic of China (release date: December 28,

2002; date of enforcement: December 28, 2002), Amendment (V) to the Criminal Law

of the People's Republic of China (release date: February 28, 2005; date of

enforcement: February 28, 2005), Amendment (VI) to the Criminal Law of the

People's Republic of China (release date: June 29, 2006; date of enforcement: June

29, 2006), Amendment (VII) to the Criminal Law of the People's Republic of China

(release date: February 28, 2009; date of enforcement: February 28, 2009), the

Decision of the Standing Committee of the National People's Congress on Amendment

to Part of Laws (release date: August 27, 2009; date of enforcement: August 27, 2009)

and Amendment (VIII) to the Criminal Law of the People's Republic of China (release

date: February 25, 2011; date of enforcement: May 1, 2011) and amended by

Amendment (IX) to the Criminal Law of the People's Republic of China (release date:

August 29, 2015; date of enforcement: November 1, 2015).

323. The clauses related to the incineration fly ash from MSW in the Criminal Law

are mainly as follows.

324. In case of a violation of the state regulation Article 338 of Crime of Polluting

Environment by discharging, dumping or disposal of radioactive wastes, wastes

containing infectious pathogens, toxic substances or other harmful substances, which

cause serious environmental pollution, the offender shall be sentenced to fixed-term

imprisonment of not more than three years or criminal detention, fine alone or together

with other penalty; in case of especially serious consequences, the offender shall be

sentenced to fixed-term imprisonment of more than three years and not more than

seven years and concurrently be sentenced to a fine;

325. "In accordance with Article 408 [Crime of Neglect of Duty Concerning

Environmental Supervision; Crime of Dereliction of Duty Concerning Food

Supervision], in case of major environmental pollution accident which causes serious


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losses of public or private property or personal casualties due to the serious

irresponsibility of the state personnel in charge of the supervision and administration

of environmental protection, such state personnel shall be sentenced to fixed-term

imprisonment of not more than three years or criminal detention."

326. The interpretations of Crime of Polluting Environment are given in the

According to Interpretation of the Supreme People's Court and Supreme People’s

Procuratorate on Certain Issues Concerning the Handling of Criminal Cases Related

to Environmental Pollution (No. 29 Fashi [2016]) promulgated on December 23, 2016

and implemented on January 1, 2017. In which, the clauses related to the incineration

fly ash from MSW are mainly as follows.

327. Article 1 The acts specified in Article 338 of the Criminal Law with one of the

following circumstances shall be deemed as serious environmental pollution,(II)

illegally discharge, dumping and dispose hazardous wastes more than three tons;

328. Article 3 The acts specified in Article 338 and Article 339 of the Criminal Law

with one of the following circumstances shall be deemed as "particularly serious

consequence", "(II) illegally discharge, dump and dispose hazardous wastes more

than one hundred tons";

329. Article 4 The criminal acts specified in Article 338 and 339 of the Criminal Law

with one of the following circumstances shall be severely punished; (IV) the enterprise

with a hazardous waste operating license violates the state regulations by discharge,

dumping and disposal of radioactive wastes, the waste with infectious pathogens, toxic

substances or other harmful substances";

330. Article 6 The enterprise without a hazardous waste operating license engages

in the collection, storage, use and disposal of hazardous wastes which causes serious

environmental pollution shall be convicted and punished in terms of offence of

environmental pollution; in case that the above act constitutes the crime of illegal

business operation, such enterprise shall be punished as the regulation with severe

punishment.

331. In accordance with the Criminal Law and its judicial interpretation, illegal


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dumping and disposal of incineration fly ash from MSW over three tons will constitute

a crime of polluting environment; illegal dumping and disposal of incineration fly ash

from MSW over one hundred tons will constitute a crime of polluting environment with

particularly serious consequence; In the event that a unit with a hazardous waste

business license (the unit which is incorporated into the exemption management and

does not need to apply for a license shall be included in this category) conducts the

above-mentioned act, it shall be given a heavier punishment on the basis of the above-

mentioned charges.

5.1.1.5 Environmental Protection Tax Law

332. The Environmental Protection Tax Law of the People's Republic of China was

adopted by the 25th Session of the Standing Committee of the Twelfth National

People's Congress of the People's Republic of China on December 25, 2016 and will

come into effect on January 1, 2018.

333. Environmental Protection Tax Law is the first separate law approved by the

Standing Committee of National People's Congress after the requirement of

"Implementing the principle of tax legalization" raised by the Third Plenary Session of

the 18th Central Committee of the CPC and the first separate law reflecting the "green

tax system" and promoting "ecological civilization construction".

334. First, the Environmental Protection Tax Law specifies the taxpayer scope of

the environmental protection tax, namely, Article 2: within the territory of the People's

Republic of China and other waters under the jurisdiction of the People's Republic of

China, the enterprises, institutions and other production operators directly discharging

taxable pollutants to the environment shall be the taxpayers of the environmental

protection tax; secondly, it specifies the types of taxable pollutants, namely Article 3:

the taxable pollutants as mentioned in this Law shall refer to the air pollutants, water

pollutants, solid wastes and noises specified in the Items and Amounts of

Environmental Protection Tax and the Taxable Pollutants and Equivalent Value

attached hereto.

335. The Schedule 1 (Items and Amounts of Environmental Protection Law) to the

Environmental Protection Law clearly stipulates that the amount of the taxable item


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"Hazardous Wastes" shall be RMB 1,000/ ton.

336. The Environmental Protection Tax Law specified the non-taxable conditions,

that is, Article 4: the enterprise with one of the following circumstances shall not be

deemed to direct discharge pollutants to the environment and may not pay the

environmental protection tax for the pollutants: (1) enterprises, institutions and other

production operators discharge taxable pollutants to the centralized sewage treatment

and centralized MSW treatment sites established in accordance with the law; (2)

enterprises, institutions and other production operators store or dispose solid wastes

in facilities and places that meet the requirements of the national and local

environmental protection standards.

337. The Environmental Protection Law also provides the suspension conditions

of environmental protection tax, namely Article 12: environmental protection tax may

be suspended in case of the following circumstances: (4) the solid waste

comprehensively utilized by the taxpayer confirms to the national and local

environmental protection standards.

338. In accordance with the above provisions of the Environmental Protection Tax

Law and the relevant existing laws and regulations, standards and norms, the

incineration fly ash from MSW treated at the MSW landfill or hazardous waste landfill,

or co-processed in cement kiln may not pay the environmental protection tax.

Otherwise, environmental protection tax (RMB 1,000/ton) shall be charged on the fly

ash.

5.1.1.6 Government Regulations

339. So far, the State Council, the Ministry of Environmental Protection and the

Ministry of Housing and Urban-Rural Development have not formulated the regulations

on the management of incineration fly ash from MSW. As the competent authority of

the construction and operation of MSW facilities, the Ministry of Housing and Urban-

Rural Development has not formulated the regulations concerning the management of

incineration fly ash from MSW.

340. As the hazardous wastes, the management of incineration fly ash from MSW


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shall comply with the following regulations.

(1) National Hazardous Waste Inventory;

341. The National Hazardous Waste Inventory was formulated and promulgated

by the Ministry of Environmental Protection, the National Development and Reform

Commission and the Ministry of Public Security on June 14, 2016 in accordance with

Order No. 39 of the Ministry of Environmental Protection.

342. In the National Hazardous Waste Inventory, "772-002-18 incineration fly ash

from MSW" is listed in the "HW18 incineration disposal residue". Therefore, the

incineration fly ash from MSW shall belong to hazardous wastes and shall be managed

in accordance with the requirements of hazardous waste management.

343. In the appendix Exemption and Management List for Hazardous Wastes to

the National Hazardous Waste Inventory, the incineration fly ash from MSW is listed

in item 4. In accordance with the List, if the incineration fly ash from MSW "meets the

requirements prescribed by Article 6.3 of Pollution Control Standards of MSW Landfill

Plants (GB16889-2008), and then the incineration fly ash from MSW shall be filled in

the MSW landfill", the landfill shall not be deemed as the management of hazardous

waste; If the incineration fly ash from MSW "meets the requirements prescribed by

Solid Wastes Pollution Control Standards for Cement Kiln Co-processing (GB30485-

2013), co-processing shall be carried out in the cement kiln", "the co-processing in

cement kiln shall not be managed as hazardous waste". Namely, the incineration fly

ash from MSW disposed in the MSW landfill or co-processed in the cement kiln may

obtain the exemption qualification of hazardous waste management under the

corresponding conditions. However, except for the above two modes of disposal, other

disposal or management processes (collection, transportation, storage and transfer,

etc.) cannot be exempted and shall be managed as per hazardous waste.

(2) Administrative Measures for Hazardous Wastes Subject to Business

License

344. Administrative Measures for Hazardous Wastes Subject to Business License

was formulated and promulgated by the State Council Order No. 408 of the People's

Republic of China (May 30, 2004) and revised by the Decision of the State Council on


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Amendment to Administrative Regulations (State Council Order No. 645 (December 7,

2013)) and the Decision of the State Council on Amendment to Administrative

Regulations (State Council Order No. 666 (February 6, 2016)).

345. Administrative Measures for Hazardous Wastes Subject to Business License

specified the business scope of the business license for hazardous wastes. In which,

Article 2 stipulates that "in the territory of the People's Republic of China, the units

engaged in the collection, storage, disposal of hazardous wastes shall apply for the

business license for hazardous wastes in accordance with the provisions of these

measures". But Article 57 of the revised edition of the Solid Law (2004) added the

requirement for the use of facilities business license, which provides that " the units

engaged in utilization of hazardous wastes shall apply for a business license to the

administrative department in charge of environmental protection of the State Council

or the administrative department in charge of environmental protection of the people's

government of province, autonomous region or municipality directly under the Central

Government.

346. According to the above provisions, the third-party operating agencies for the

collection, storage, landfill disposal and comprehensive utilization of incineration fly

ash from MSW shall apply for the business license for hazardous wastes.

347. But according to the Exemption and Management List for Hazardous Wastes

attached to the National Hazardous Waste Inventory, the incineration fly ash from

MSW landfill and the cement kiln co-processing (utilizing) the incineration fly ash from

MSW need not to apply for the business license for hazardous wastes. But except for

the MSW landfill and co-processing of the cement kiln, other management facilities

(collection, transportation and storage, the facilities) disposing or using the incineration

fly ash from MSW still need to apply for the business license for hazardous waste.

348. In accordance with the Administrative Measures for Hazardous Wastes

Subject to Business License, the business license for hazardous wastes of the

incineration fly ash from MSW shall be issued by the administrative department in

charge of environmental protection at the provincial level.

(3) Management of Hazardous Wastes Duplicated Form


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349. Management of Hazardous Wastes Duplicated Form was promulgated by the

Order No.5 issued by State Environmental Protection Administration (June 22, 1999).

350. Management of Hazardous Wastes Duplicated Form stipulates the

application and using process, filling and preservation requirements as well as

supervision demands of the duplicated form.

(4) Unit Management Plans’ Formulating Guidance on the Generation of Hazardous Wastes

351. Unit Management Plans’ Formulating Guidance on the Generation of

Hazardous Wastes was promulgated by Announcement No.7 in 2016 issued by

Ministry of Environmental Protection on January 25, 2016.

352. Unit Management Plans’ Formulating Guidance on the Generation of

Hazardous Wastes raises the preparation requirements for the hazardous waste

management plan, including the preparation unit, form, time and content. Unit

Management Plans’ Formulating Guidance on the Generation of Hazardous Wastes

stipulates that the MSW incineration plants generating incineration fly ash from MSW

shall regularly formulate and report its Hazardous Wastes’ Management Plan together

with the Hazardous Waste Management Plan Recording Registration Form . In the

Hazardous Waste Management Plan, the MSW incineration plant shall report the

annual production amount of fly ash and the mode, facility conditions, quantity and

other information of the management process such as preservation, transferring,

disposal and utilization according to the planed disposal quantity of the MSW,

summarize the management plan implementation of the previous year and put forward

the ledger system requirements connected with the management plan and production

records.

(5) Pollution Prevention Technique Policy for Co-processing of Solid Waste in

Cement Kiln

353. The Pollution Prevention Technique Policy for Co-processing of Solid Waste

in Cement Kiln was promulgated by the Announcement No. 72 in 2016 issued by the

Ministry of Environmental Protection on December 6, 2016.


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354. Based on the reaffirmation of the implementation of the relevant requirements

of the Solid Waste Pollution Control Standards in Cement Kiln Co-processing

(GB30485-2013) and Solid Wastes Environmental Protection Technical Specifications

for Cement Kiln Co-processing (HJ662-2013), the Pollution Prevention Technique

Policy for Co-processing of Solid Waste in Cement Kiln raises higher technical

requirements to the cement kiln for the co-processing of solid wastes. The

requirements to the cement kiln for the co-processing of solid wastes: the newly-built,

rebuilt or expanded cement enterprises disposing hazardous waste after the issuance

of the technique policy shall select the cement kiln with the single-line design clinker

production scale of 4,000t/day or more.

355. Therefore, according to the current regulations, policies, standards and

specifications, the cement kiln facilities for the co-processing of incineration fly ash

from MSW shall meet the following requirements: a. new dry cement kiln with a

production scale of no less than 4,000t clinker/day for single-line design; b. adopting

the kiln-mill integration model; c. High-efficiency bag collector is used as the dust

removal facility in the cement kiln and kiln tail waste-heat utilization system.

356. The Pollution Prevention Technique Policy for Co-processing of Solid Waste

in Cement Kiln mainly reiterates the technical requirements for flue gas dust removal

facilities used for co-processing of solid waste in cement kiln, "for the facilities used for

co-processing of solid waste in cement kiln, the kiln tail flue gas dust removal shall

adopt high-efficient bag collector; for the facilities for the co-processing of solid waste

that was built or of which the environmental impact assessment file has been approved

before March 1, 2014, the kiln tail uses the electrostatic precipitator to continuously

improve the operation stability and efficiency in order to ensure that the pollutant

discharge meets the standards and encourage replace the electric precipitator with

high-efficient bag collector. The operation and maintenance management of the

cement kiln dust collector for solid waste treatment should be strengthened to ensure

the perfect synchronous operation of the dust collector and the cement kiln

production."

5.1.1.7 Standards and Specifications

357. The Ministry of Environmental Protection (the former State Bureau of


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Environmental Protection, the former State Environmental Protection Administration)

has developed and or is developing a series of pollution control standards and

technical specifications for hazardous waste and incineration fly ash from MSW. In

addition, the Ministry of Housing and Urban-Rural Construction has formulated the

Technical Specifications for Sanitary Landfill Disposal of MSW; The National Technical

Committee for Cement Standardization has formulated the Technical Specifications

for the Co-processing of Solid Waste in Cement Kilns. Both standards are related to

the disposal (co-processing) management of incineration fly ash from MSW.

(1) Pollution Control Standards for Hazardous Wastes Landfill

358. The Pollution Control Standards for Hazardous Wastes Landfill (GB 18598-

2001) has made stipulations on the environmental protection requirements involved in

the construction and operation of the hazardous waste safe landfill, including the

admission condition, site selection, design, construction, operation, closure and

monitoring of the landfill. The landfills for the landfill disposal of incineration fly ash

from MSW must meet the requirements of this standard.

359. According to this standard, the incineration fly ash from MSW shall be

pretreated in the hazardous waste landfill and the content of heavy metals in the

leaching solution shall meet the requirements of the standard.

(2) Landfill Pollution Control Standards of Municipal Solid Waste

360. Landfill Pollution Control Standards of Municipal Solid Waste (GB16889-2008)

stipulates the requirements of site selection, engineering design and construction,

admission conditions, landfill work, closure, later maintenance and management,

pollutants discharge limits and environmental monitoring of the MSW landfill, etc.

Meanwhile, this standard also specifies the specific discharge limit of water pollutants.

The MSW landfills for the landfill disposal of incineration fly ash from MSW must meet

the requirements of this standard.

361. The Landfill Pollution Control Standards of Municipal Solid Waste specially

stipulates the standard for admission and disposal of the incineration fly ash from MSW.

In accordance with Clause 6.3 of this standard, the incineration fly ash from MSW

meeting the following conditions is allowed to be moved into the MSW landfill:


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a. Moisture content is lower than 30%;

b. Dioxins content is less than 3ug TEQ / kg;

c. The concentration of hazardous ingredients in the HJ / T300 prepared leach

solution is lower than the fixed limit in table 1.

362. Meanwhile, in accordance with Clause 6.5 of the standard, "the incineration

fly ash from MSW meeting the requirements of Clause 6.3" "shall be separately buried

in different areas in the MSW landfill."

(3) Technical Specifications for Sanitary Landfill Disposal of MSW

363. Technical Specifications for Sanitary Landfill Disposal of MSW (GB50869-

2013) raises the specific technical requirements for the siting, design, construction,

acceptance and operation management of the newly-built, rebuilt and expanded MSW

sanitary landfill treatment projects.

364. In accordance with Clause 3.0.4 of this standard, the incineration fly ash from

MSW and the incineration residue from medical waste after disposal meeting the

conditions stipulated in the existing national standard Pollution Control Standards of

MSW Landfill Plants (GB16889) are allowed to be moved into the MSW landfill for

landfill disposal. Separate landfill areas which can effectively separate the MSW landfill

areas in disposal.

365. In accordance with this standard, the incineration fly ash from MSW to be

disposed in the MSW landfill shall meet the requirements of the standard and Landfill

Pollution Control Standards of Municipal Solid Waste (GB16889-2008).

(4) Solid Waste Pollution Control Standards for Cement Kiln Co-processing

366. Solid Waste Pollution Control Standards for Cement Kiln Co-processing

(GB30485-2013) stipulates the technical requirements for the solid waste co-

processing facilities of the cement kiln, the requirement for the nature of the waste,

operation technical requirements, technical requirements, pollutant emission limit, the

pollutant control requirements for produced cement products, monitoring and

supervision management requirements.


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367. In the co-processing of incineration fly ash from MSW in the cement kiln, in

addition to the general requirements in this standard, the special requirements for

hazardous wastes shall be executed.

. Requirements for facilities for co-processing of incineration fly ash from

MSW

368. “4.1 The cement kilns for co-processing of solid waste shall meet the following

conditions: a) new dry cement kiln with a production scale of no less than 2,000t

clinker/day for single-line design; b) adopting the kiln-mill integration model; c) High-

efficiency bag collector is used as the dust removal facility in the cement kiln and kiln

tail waste-heat utilization system; d) for the cement kiln for the co-processing of

hazardous waste, the destruction and removal efficiency measured as per the

requirement of the Solid Wastes Environmental Protection Technical Specifications for

Cement Kiln Co-processing (HJ662) shall be no less than 99.9999%;e) for the cement

kiln for co-processing of solid waste with the transformed facilities, the original facilities

before the transformation shall meet the requirements of GB 4915 for two consecutive

years.”

. The adding technical requirements for co-processing of incinerator fly

ash from MSW in cement kiln

369. "5.2 The solid waste to be delivered into the kiln shall have the relatively stable

chemical composition and physical properties; the contents and adding volumes of

heavy metal and harmful elements (chlorine, fluorine and sulfur, etc.) shall meet the

requirements of the Solid Wastes Environmental Protection Technical Specifications

for Cement Kiln Co-processing (HJ662)".

370. "6.1 In the operation process, the adding point and method shall be properly

selected based on the features of the solid waste according to the Solid Wastes

Environmental Protection Technical Specifications for Cement Kiln Co-processing

(HJ662)".

. The technical requirements for cement products produced by the cement

kiln for co-processing of incineration fly ash from MSW


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371. "8.1 The cement products produced by cement kilns for co-processing of solid

waste shall meet the relevant national standards".

372. "8.2 The leaching of pollutants from cement products produced by cement

kilns for co-processing of solid waste shall meet the requirements of relevant national

standards".

. Flue gas emission limit of cement kilns for co-processing of incineration

fly ash from MSW

373. "7.1 For the co-processing of solid waste in cement kiln, the emission limits of

particulate matter, sulfur dioxide, nitrogen oxides and ammonia from the cement kiln

and kiln tail waste-heat utilization system shall be executed in accordance with the

requirements of GB 4915".

374. 7.2 For the co-processing of solid waste in cement kiln, the pollutants other

than the air pollutants listed in clause 7.1 of the standard from the cement kiln and kiln

tail waste-heat utilization system exhaust funnel shall be executed in accordance with

the highest allowable discharge concentration specified in table 1".

(5) Solid Wastes Environmental Protection Technical Specifications for

Cement Kiln Co-processing

375. Solid Wastes Environmental Protection Technical Specifications for Cement

Kiln Co-processing (HJ662-2013) stipulates the requirements of environmental

protection technology in the facility selection, construction and transformation,

operation and pollution control and other aspects of the cement kiln for co-processing

of solid wastes.

376. According to this standard, the incineration fly ash from MSW can be co-

processed in cement kilns. In view of the nature of the incineration fly ash from MSW

and according to the regulation, the incineration fly ash from MSW is suitable to be

added to the feed-end chamber and raw mill of the cement kiln.

377. The specification also specifies the adding limits for heavy metals, sulfur,

chlorine, and fluorine in wastes for co-processing. In which, the limit of chlorine content


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is stipulated as: "6.6.8 The co-processing enterprises shall control the dosage of

chlorine (Cl) and fluorine (F) elements added into the kiln with the materials according

to the characteristics of cement production process in order to ensure the normal

production of cement and the quality of clinker meet the national standards." The

content of fluorine in the kiln shall not be greater than 0.5%, and the content of chlorine

should not be greater than 0.04%". That is, the chlorine content in all materials to be

added in the kiln, including the incineration fly ash from MSW for co-processing, the

raw materials and fuel, shall not exceed 0.04%. However, the content of chlorine in

MSWI fly ash is between 10% - 30%, and the demand will not be satisfied if it is directly

added. Therefore, Dechlorination treatment shall be made before the co-processing of

incineration fly ash from MSW in cement kiln.

(6) Technical Specifications for the Co-processing of Solid Waste in Cement

Kilns

378. The Technical Specifications for the Co-processing of Solid Waste in Cement

Kilns (GB30760-2014) stipulates the quality requirements of cement products

produced by solid waste for co-processing and the standards for the contents of

hazardous substances.

379. In accordance with clause 7.1 of this standard, "in the co-processing of solid

waste in cement kiln, the cement clinker produced in the cement kiln shall meet the

requirements of GB/T 21372-2008, and the content of heavy metals in cement clinker

shall not exceed the limits specified in table 2"; In accordance with clause 7.1 of this

standard, "in the co-processing of solid waste in cement kiln, the content of heavy

metal leached from the cement clinker shall not exceed the limit specified in Table

3";Article 8.2 provides that "the determination of extractable heavy metals in cement

clinker shall be carried out according to the method specified in GB/T 30810, in which

the sample preparation shall be carried out as per clause 5.2 of GB/T 21372-2008".

The reference standards involved in these standards are the Portland Cement Clinker

(GB/T 21372-2008) and Methods for Determination of Leachable Heavy Metals in

Cement Mortar (GB/T 30810-2014).

5.1.2 Local Regulations

380. Up to now, 14 of China's 31 provinces, municipalities and autonomous regions


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have specially formulated local regulations for solid waste or hazardous waste, and

Shanghai Municipality has released government guidance opinions on management

of MSW incineration fly ash; 3 of the 31 have issued local standards for disposal of

solid waste (technical specifications), among which Chongqing Municipality has issued

a technical specification for engineering of MSW incineration fly ash disposal by using

secondary materials.

5.1.2.1 Local Regulations

381. The following are local regulations concerning solid waste or hazardous waste

that have been implemented are listed below.

Rules of Hebei Province on the Prevention and Control of Environmental

Pollution by Solid Waste (passed at the 2nd session of the 14th meeting of

the standing committee of the people's congress of Hebei Province on

March 26, 2015, taking effect on June 1, 2015);

Measures of Liaoning Province on the Prevention and Control of

Environmental Pollution by Solid Waste (examined and approved at the 9th

session of the 94th executive meeting of the Liaoning Provincial People's

Government on December 18, 2001, taking effect on March 1, 2002)

Rules of Jilin Province on the Prevention and Control of Environmental

Pollution by Hazardous Waste (approved at the 10th session of the 22nd

meeting of the standing committee of the people's congress of Jilin Province

on September 14, 2005, taking effect on December 1, 2005)

Measures of Shandong Province on Implementation of the Law of the

People's Republic of China on the Prevention and Control of Environmental

Pollution by Solid Waste (passed at the 9th session of the 31rd standing

committee of the people's congress of Shandong Province on September

28, 2002, taking effect on January 1, 2003)

Measures of Shanghai Municipality on the Prevention and Control of

Pollution by Hazardous Waste (issued on January 6, 1995 by Shanghai

Municipal People's Government and amended in accordance with the 53rd

Order of the Shanghai Municipal People's Government promulgated on

December 14, 1997 )

Rules of Jiangsu Province on the Prevention and Control of Environmental

Pollution by Solid Waste (passed at the 11th session of the 11th standing


145

committee of the people's congress of Jiangsu Province on September 23,

2009, taking effect on January 1, 2010)

Rules of Zhejiang Province on the Prevention and Control of Environmental


committee of the people's congress of Jiangsu Province on March 29, 2006,

taking effect on June 1, 2006)

Provisions of Fujian Province on the Prevention and Control of

Environmental Pollution by Solid Waste (passed at the 11th session of the

12th standing committee of the people's congress of Fujian Province on

November 26, 2009, taking effect on January 1, 2010)

Rules of Guangdong Province on the Prevention and Control of

Environmental Pollution by Solid Waste (passed at the 10th session of the

8th standing committee of the people's congress of Guangdong Province on

January 14, 2004; amended for the first time according to the Decision of the

Standing Committee of the People's Congress of Guangdong Province on

Amendment of Relevant Administrative Compulsory Articles in Seven

Regulations (Rules of Guangdong Province on the Prevention and Control of

Environmental Pollution by Solid Waste, etc.) passed at the 11th session of

31st standing committee of the people's congress of Guangdong Province

on January 9, 2012; amended for the second time in accordance with the

Decision of the Standing Committee of the People's Congress of

Guangdong Province on Amendment of Twenty Tree Regulations (Rules of

Guangdong Province on Management of Private Technological Enterprises,

etc.) passed at the 11th session of 35th standing committee of the people's

congress of Guangdong Province on July 26, 2012)

Rules of Henan Province on the Prevention and Control of Environmental


committee of the people's congress of Henan Province on September 28,


Rules of Sichuan Province on the Prevention and Control of Environmental


committee of the people's congress of Sichuan Province on September 25,


Rules of Shanxi Province on the Prevention and Control of Environmental


committee of the people's congress of Shanxi Province on November 19,


146

2015, taking effect on April 1, 2016)

Measures of Ningxia Hui Autonomous Region on Management of

Hazardous Waste (discussed and approved at the 89th executive meeting of

the People's Government of Ningxia Hui Autonomous Region on February

27, 2011, taking effect on April 1, 2011)

Measures of Xinjiang Uygur Autonomous Region on the Prevention and

Control of Environmental Pollution by Hazardous Waste (examined and

approved at the 11th session of the 9th executive meeting of the People's

Government of Xinjiang Uygur Autonomous Region on January 8, 2010,

issued on January 20, 2010 in accordance with the 163rd Order of the

People's Government of Xinjiang Uygur Autonomous Region, taking effect

on May 1, 2010)

382. All the above-mentioned implemented local regulations about solid waste or

hazardous waste have further reiterated and reinforced relevant provisions of the Law

of the People’s Republic of China on the Prevention and Control of Environmental

Pollution by Solid Waste. Those local regulations, however, have not made any

changes strengthening or weakening relevant stipulations in the Law of the People’s

Republic of China on the Prevention and Control of Environmental Pollution by Solid

Waste about management of MSW incineration fly ash.

383. On December 14, 2012, Shanghai Municipal Environmental Protection

Bureau and Shanghai Greenery and Public Sanitation Bureau jointly formulated and

issued Guidance Opinions on Strengthening Environmental Management of the MSW

Incineration Fly Ash. Six specific guidance opinions (perfecting layout of landfill site of

the fly ash, reasonably guiding where to dump the disposed fly ash, strengthening pre-

treatment of the fly ash , carrying out measures to prevent and control pollution,

practically strengthening environmental supervision and encouraging utilization of fly

ash resources) were proposed in this guidance document specially made for

management of MSW incineration fly ash. For specific disposal ways, the guidance

document requirements to construct (or expand) landfill sites special for MSW

incineration fly ash in Shanghai Jiading, Laogang and Chongming districts, and to

pretreat the MSW incineration fly ash in accordance with the Standard for Pollution

Control on the Security Landfill Site for Hazardous Waste (GB18598-2001). For other

disposal (utilization) modes, this guidance document just proposes to "encourage


147

stabilization of pre-treatment of fly ash incineration, R&D of resources utilization

technology and construction of fly ash resources utilization facilities for reclamation

technology applicable for engineering transformation as well as adjust appropriately

places to dump the disposed MSW incineration fly ash by some of the disposal facilities

so as to save landfill space and promote the sustainable development", and no specific

comments or suggestions have been put forward. This guidance document has

attached to it Technical Requirement for Pre-treatment of MSW Incineration Fly Ash,

putting forward specific requirements for pollution prevention and control during and

management of the pre-treatment process of MSW incineration fly ash, but covering

no pre-treatment technology.

384. On May 29, 2012, the Shanghai Municipal Environmental Protection Bureau

and Shanghai Municipal Transportation and Port Authority jointly developed and

issued Provisions on the Prevention and Control of Pollution by Road Transportation

of Hazardous Waste (Trial) (HuHuanBaoFang[2012]No.181). According to this

document, MSW incineration fly ash shall be classified as "common hazardous waste"

and shall be transported "using special enclosed containers and vans". Specific

requirements for the transportation units and management of their personnel have

been proposed in this document.

5.1.2.2 Local Standards

385. Beijing Municipality, Shanghai Municipality and Chongqing Municipality have

developed local standards for solid waste management.

Local standard of Shanghai Municipality - Emission Standard of Air

Pollutants for Municipal Solid Waste Incineration (DB31/768-2013);

Local standard of Beijing Municipality - Emission Standard of Air Pollutants

for Municipal Solid Waste Incineration (DB11/502-2007);

Local standard of Beijing Municipality - Emission Standard of Air Pollutants

for Hazardous Waste Incineration (DB11/503-2007);


148

Chongqing Municipal Environmental Protection Bureau - Technical

Specification for Engineering of Disposal of MSW Fly Ash Using Secondary

Material Composite Technology (Trial) (YuHuanFa[2015]No.56).

386. Local standards of Beijing Municipality and Shanghai Municipality cover no

content about treatment, disposal and management of MSW incineration fly ash.

387. Technical Specification for Engineering of Disposal of MSW Fly Ash Using

Secondary Material Composite Technology (Trial) issued by Chongqing Municipal

Environmental Protection Bureau raises corresponding engineering technical

requirements for treatment of hazardous waste like MSW incineration fly ash,

electroplating sludge and chromium slags using sintering technology. However,

because of a lack of specific disposal or utilization approaches for the waste (materials)

disposed by such technology and a lack of standards which such disposed waste shall

or can reach, it is difficult for this document to play a fundamental role in treatment and

disposal of MSW incineration fly ash.

5.2 Environment Supervision Systems and Management

Organization Frames of MSW Incineration Fly Ash in China

5.2.1 Ministry of Environmental Protection

5.2.1.1 Management Office of Solid Waste

388. According to the Law of the People’s Republic of China on the Prevention and

Control of Environmental Pollution by Solid Waste, "competent administrative

departments of environmental protection under the State Council shall conduct unified

supervision and administration of the prevention and control of environment pollution

by solid waste all over the county."

389. Ministry of Environmental Protection has a Management Office of Solid Waste

(the "Solid Office") to carry out such function. The Solid Office belongs to the

Department of Soil Environment Management, which is responsible for "supervision

and management of prevention and control of soil, solid waste, chemicals and heavy

metal pollution; formulation, organization and implementation of policies, plans, laws,


149

administrative regulations and departmental rules, standards and specifications for

prevention and control of soil, solid waste, chemicals and heavy metal pollution;

proposal and formulation of soil environmental function zoning; calculation and

determination of the soil environmental capacity; assessment of soil environmental

carrying capacity; organization and implementation of environmental management

systems like business license and export examination & approval for hazardous waste,

import license for solid waste, import & export registration for toxic chemicals and

environmental management registration for new chemicals; undertakings jobs about

emission license, total amount control and emissions trading of soil pollutants;

organization and implementation of report and registration of industrial waste like

hazardous waste, medical waste and electronic waste; supervision and management

of soil environment protection and mulch film pollution prevention and control;

domestic performance of relevant international conventions".

390. Correspondingly, the Solid Office is responsible for "formulation of policies,

plans, laws, administrative regulations, department regulations, standards,

specifications and directories for solid waste management; organization and

implementation of business license and export examination & approval for hazardous

waste, import license for solid waste as well as report and registration of industrial

waste like hazardous waste, medical waste and electronic waste; supervision of

pollution prevention and control about recycling of renewable resources like electronic

waste and sludge; domestic performance of relevant international conventions".

391. Thus it can be seen that the main responsibility of the Ministry of

Environmental Protection is to develop policies, regulations, standards and other

documents relating to management of the MSW incineration fly ash. While, for specific

supervision functions like business license and approval, Ministry of Environmental

Protection is responsible for "organization and implementation". In fact, those specific

supervision functions are actually implemented by the local competent administrative

environmental protection departments (mainly province-level ones).

5.2.1.2 Solid Waste and Chemicals Management Center, Ministry of

Environmental Protection

392. Solid Waste and Chemicals Management Center (the Center), now a bureau-


150

level public institution directly subordinate to the Ministry of Environmental Protection

and technical support institution of the Ministry of Environmental Protection on

management of solid waste, chemicals, pollution sites and heavy metal environment,

was established in June 2013 by merging former Solid Waste and Chemicals

Management Center and Chemicals Registration Center of the Ministry of

Environmental Protection. The Center receives professional guidance from Pollution

Prevention and Control Department of the Ministry of Environmental Protection, and

the Center is mainly responsible for:

(I) undertaking researches on policies, regulations, strategies, plans, standards and

technical specifications about the prevention and control of risk and pollution caused

by solid waste and chemicals.

(II) conducting investigations, analysis & testing, technical identifications, scientific

researches and international cooperation related to prevention and control of

pollution by solid waste and environmental management of chemicals.

(III) entrusted by the Ministry of Environmental Protection, assisting in conduction of

site inspection and daily supervision for environmental management of solid waste

and chemicals as well as undertaking technical review of relevant administrative

examination and technical guidance and service work for local management

institutions of solid waste and chemicals.

(IV) carrying out relevant technical support for environmental management of

polluted sites as well as prevention and control of heavy metal pollution.

(V) conducting information analysis, technical services, publicity, training and social

consultation on environmental management of solid waste and chemicals.

(VI) undertaking other tasks assigned by the Ministry of Environmental Protection.

393. It can be seen from the above introduction that in view of the supervision and

management of MSW incineration fly ash, the Center is responsible for providing the

Ministry of Environmental Protection with technical support to formulate relevant

policies, regulations, standards and other management documents as well as

undertaking inspection and technical guidance work assigned by the Environmental

Protection Department against enterprises producing, disposing and utilizing MSW


151

incineration fly ash and management organizations of MSW incineration fly ash.

5.2.2 Local Competent Administrative Departments of Environmental Protection

394. Technology and management measures against MSW incineration fly ash,

including application, review and issuance of business license for hazardous waste,

approval and implementation supervision of duplicate forms for transfer, etc., are

actually implemented by province-level competent administrative departments of

environmental protection. Among those measures, business license system for

hazardous waste is critical to the construction and technical development of disposal

and utilization facilities of MSW incineration fly ash.

395. Business license system for hazardous waste is implemented by Appropriate

Department of Solid Waste Management of the province-level competent

administrative departments of environmental protection and province-level

Management Center of Solid Waste. In general, the province-level Management

Center of Solid Waste organizes and implements technical review as well as develops

of review conclusion against the application unit of business license for hazardous

waste; the Appropriate Department of Solid Waste Management, on the basis of the

review conclusion, drafts the license; the province-level competent administrative

departments of environmental protection gives instructions about whether relevant

units are allowed for the license or not, and issue the license for the unit that has been

allowed.

396. Describe organization structuring and responsibilities of local competent

administrative departments of environmental protection and the Management Center

of Solid Waste taking Beijing Municipality as an example.

5.2.2.1 Appropriate Department of Solid Waste Management

397. At present, various regions are adjusting and reorganizing relevant

administrative organizations in reference to organization structuring of the Ministry of

Environmental Protection, including forming the Management Office of Soil

Environment in charge of solid waste management, but the progress of adjustment

and reorganization is not uniform.


152

398. On the official website of the Beijing Municipal Environmental Protection

Bureau, it is still the Office of Pollution Prevention and Control (also called

Management Office of Acoustic Environment and Solid Waste) in charge of solid waste

management. We can see from this website that the Office of Pollution Prevention and

Control is responsible for "drafting local regulations and governmental rules on the

prevention and control of pollution of or by industrial waste, solid waste, hazardous

waste, soil, and noise, and drawing up relevant standards and plans as well as

supervising corresponding implementation; supervising and managing industrial

pollution sources in accordance with the law and carrying forward pollution prevention

and control work of key industries and enterprises; engaging in promotion of clean

production; supervising and managing generation, collection, storage, transportation,

utilization, disposal and transfer of solid waste and hazardous waste in accordance

with the law, and undertaking relevant administrative licensing work; organizing report

and registration of industrial waste like hazardous waste, medical waste and electronic

waste; reviewing and approving the qualification to dispose waste electrical and

electronic products and supervising and inspecting the disposal activities; supervising

and managing the prevention and control of soil pollution; undertaking prevention and

control work of industrial noise pollution and coordinating noise pollution prevention

and control work in respects of daily life, construction, transportation and so on". At

present, the administrative licensing of solid waste (hazardous waste) mainly includes

examination and approval of business license for hazardous waste and inter-provincial

transfer of hazardous waste. In administrative regions of Beijing Municipality, the Office

of Pollution Prevention and Control is responsible for examination, approval and

issuance of the business license for hazardous waste of MSW incineration fly ash

facilities.

5.2.2.2 Management Center of Solid Waste

399. Presently, province-level administrative regions over the whole country all

have technical support institutions for solid waste management, functions of which

include, apart from management of solid waste, the environmental management of

chemicals or radiation.

400. Management Center of Solid Waste and Chemicals, Beijing Municipal

Environmental Protection Bureau (the "Center") is a subordinate public institution of


153

Beijing Municipal Environmental Protection Bureau, and possesses certain law

enforcement power at the same time. The Center of Solid is specifically responsible

for "technical, transactional, auxiliary work in respects of supervision and

administration of solid waste, hazardous waste and chemicals". For specific

management of the MSW incineration fly ash, the Center is mainly responsible for

organizing technical review against the business license for hazardous waste for

disposal and utilization facilities of MSW incineration fly ash, and putting forward

approval suggestions about the business license for hazardous waste to Beijing

Municipal Environmental Protection Bureau based on conclusions of the technical

review.

401. It is important to note that the technical review of business license for

hazardous waste is mainly based on above-mentioned national regulations and

standards. Level and extent of the review varies greatly because the review standard

is defective.

5.3 Standards and Systems about MSW Incineration Fly Ash

5.3.1 MSW Incineration Standards

402. Content about disposal of MSW incineration fly ash in the Standard for

Pollution Control on MSW Incineration (GB 18485-2014) only requires that "MSW

incineration fly ash and slag shall be separately collected, stored, transported and

disposed of ; MSW incineration fly ash shall be managed as hazardous waste, and

disposal of MSW incineration fly ash (if any) at the MSW landfill site shall meet the

requirements of GB 16889 (Standard for Pollution Control on the Landfill Site of

Municipal Solid Waste); disposal in cement kiln (if any) shall meet the requirements of

GB 30485 (Standard for Pollution Control on Co-processing of Solid Waste in Cement

Kiln)", and no relevant specific technical requirements have been put forward.

403. In this Standard, however, categories of the waste to be incinerated are clearly

defined, explicitly stipulating that hazardous waste other than medical waste" shall not

be incinerated in the MSW incinerator". Thus, content of heavy metals, dioxins and

other harmful substances in the MSW incineration fly ash be effectively controlled so

as to avoid insurmountable obstacles to later treatment and disposal.


154

5.3.2 Standards for Disposal of MSW Incineration Fly Ash

404. Currently, the main disposal way of MSW incineration fly ash is landfill.

According to existing standards and regulations, MSW incineration fly ash can be

disposed at hazardous waste landfill sites or MSW landfill sites.

5.3.2.1 Hazardous Waste Landfill Site

405. Standard for Pollution Control on the Security Landfill Site for Hazardous

Waste (GB 18598-2001) specifies the requirement or accessing the landfill site. The

MSW incineration fly ash shall be pretreated before accessing the landfill site, and can

be disposed at the landfill site only after matching the standard. The above requirement

refers to heavy metal content in leach solution of the waste, and the leach solution is

prepared using the deionized water leaching method.

5.3.2.2 MSW Landfill Site

406. Standard for Pollution Control on the Landfill Site for Municipal Solid Waste

(this "Standard") allows accessing of MSW incineration fly ash to MSW landfill sites,

but pre-treatment is needed to meet the accessing requirement in this Standard.

According to Article 6.3 of this Standard, the MSW incineration fly ash can access the

MSW landfill site if the following requirements are met:

water content below 30%;

dioxin content below 3μgTEQ/Kg;

concentration of hazardous ingredient in the leach solution prepared in

accordance with HJ/T 300 is below the limit value specified in Table 4-6.

407. The leachate prepared in accordance with HJ/T 300 is a simulated leachate

of the MSW landfill site made using the acid buffer-solution method.

408. At the same time, this Standard requires that the MSW incineration fly ash

"shall be buried in an individual partition".


155

5.3.3 Standards for Comprehensive Utilization of MSW Incineration Fly Ash

409. Based on generation characteristics of MSW incineration fly ash and

technology, economy and management level of our country at present, for

comprehensive utilization, MSW incineration fly ash is mainly used to produce

construction material. Construction materials that can be produced using MSW

incineration fly ash mainly include cement (used as raw material, clinker, mixed

material, etc.), concrete aggregate, concrete mixed material, roadbed material, bricks

and tiles, etc.

5.3.3.1 Cement

410. Co-processing of MSW incineration fly ash (as raw material) in cement kilns

shall meet all requirements described in Standard for Pollution Control on Co-

processing of Solid Waste in Cement Kiln (GB30485-2013), including the requirement

for type of the cement kiln that can be used for the co-processing of MSW incineration

fly ash as well as special requirements for pollutant discharge of the cement kiln.

411. Operation process of co-processing of MSW incineration fly ash in cement

kilns shall meet all requirements described in Environmental Protection Technical

Specification for Co-processing of Solid Waste in Cement Kiln (HJ662-2013), including

determination of position and rate for adding. According to this requirement and the

nature of MSW incineration fly ash, dechlorination treatment must be carried out

against the MSW incineration fly ash before being co-processed in the cement kiln.

412. Quality of cement produced using MSW incineration fly ash as raw material

has to meet, apart from quality standards for cement products, the standard for content

of harmful substances in cement products stipulated in Technical Specification for Co-

processing of Solid Waste in Cement Kiln (GB30760-2014).

5.3.3.2 Others

413. So far, in China there is no any kinds of standards and specifications based

on which MSW incineration fly ash can be used to produce construction material in

addition to cement, which is a key factor in preventing production of construction


156

material apart from cement using MSW incineration fly ash. Because there is no

technical basis, it is difficult to obtain the support and approval from competent

administrative departments of environmental protection in the construction of projects

and facilities for producing construction material using MSW incineration fly ash.

414. Technical Specification for Pollution Control on Municipal Solid Waste

Incineration and Technical Policy for Pollution Control on Municipal Solid Waste

Incineration are now under formulation of the Ministry of Environmental Protection,

which will cover restricted conditions, basic requirements as well as key technical

parameters for production of construction material using MSW incineration fly ash.

Formulation and implementation of those two documents may make up for above-

mentioned deficiency and promote sound development of such technology.

5.4. Summary

415. This chapter mainly collects and arranges existing policies and regulations

related to the management of MSW incineration fly ash in China. It also combs through

existing frames and responsibilities of management system and authorities about

MSW incineration fly ash and studies on existing technical specifications and

standards of MSW incineration, especially fly ash generated during the MSW

incineration process.

416. It can be analyzed from the research that relevant regulations, standards and

specifications related to the treatment and disposal of MSW incineration fly ash in

China basically act as partial clauses of standard specifications on the treatment and

disposal of other waste. Besides, systematical standard specifications related to the

treatment and disposal of fly ash are missing. Therefore, normative and standard

systems related to the treatment and disposal as well as resource utilization of MSW

incineration fly ash in China should be improved.

TA-8963 PRC Final Report Chapter VI

157

CHAPTER6 ADVANCED INTERNATIONAL

EXPERIENCE OF MSWI FLY ASH MANAGEMENT

417. Although incineration technology can drastically reduce weight and volume of

waste, it generates secondary wastes such as bottom ash and fly ash. Fly ash contains

much toxic substances such as heavy metals, dioxin etc. Therefore, the countries

which introduced an incineration technology in early stage recognized that fly ash was

one of hazardous waste. However, legal definition of fly ash as hazardous waste is not

so old. In Germany, the waste disposal law was established in 1972 and catalogue of

hazardous waste was firstly shown in 1975. After that, technical regulation of

hazardous waste was decided in 1991. In The Netherland, the waste substances act

was enacted in1977 and The integrated approach was realized in the Environmental

Management Act 1993. The Act covers a wide range of aspects such as waste

collection, hazardous waste disposal, air quality, noise nuisance, environmental

permits, and setting of environmental management strategies. In US, the argument on

definition of incineration residue continued from 1976, in 1994, incineration ash was

regarded as one of hazardous waste under Resource Conservation and Recovery Act.

In Japan, the fly ash from MSWI was designated as specially controlled waste in

amendment of The Waste Disposal and Public Cleansing Law in 1991.

418. Treatment technologies for MSWI fly ash depends on various situation of

countries such as economics, land use, environmental policy etc. because

environmental standards also depends on their factors. For example, Japan has

narrow land and high population density, which suggests that Japan cannot find landfill

site easily. So, to reduce the disposal amount of waste has a high priority. On the other

hand, the waste management in US is in the different condition. How to set

environmental standards is also different among countries. The prudence avoidance

principle has been adopted in Australia, Sweden, and several US states. The ‘‘As Low

As Reasonably Achievable” (ALARA) principle plays an important part in the

enforcement of environmental law in the Netherlands. At the European level, the ‘‘Best

Available Technology Not Entailing Excessive Cost” (BATNEEC) principle is used.

419. In this chapter, international experiences of MSWI fly ash management are

introduced.


158

6.1 Japan

6.1.1 MSW Incinerated and MSWIP Fly Ash Generation and Characteristics

6.1.1.1 Basic Flow of Waste Incineration Treatment and Definition of Fly Ash

420. Shown below in Table 6-1 and Figure 6-1 and 6-2 is comparative basic flows

of waste incineration plants featuring on their exhaust gas treatment, BF Catalytic

Denitrification Gas Cleaning and Reaction Tower BF Catalytic Denitrification.

Table 6-1 Features of Exhaust Gas Treatment Flow

Overall System BF＋Wet-type

System Dry-type＋BF System

Removal

Performance

Soot and Dust

20mg/m3Nor below

(Design Standard

Value)

10mg/m3Nor below (Design

Standard Value)

Hydrogen

Chloride

15ppmor below

(Design Standard

Value)

20ppmor below

(Design Standard Value)

Nitrogen Oxide

Total Load Control

Value (Installation

Standard Value)

Total Load Control Value

(Installation Standard

Value)

Sulfur Oxide

20ppm or below

(Design Standard

Value)

20ppmor below

(Design Standard Value)

Mercury

0.05mg/m3N or below

(Design Standard

Value)

Removal Ratio: Approx.50%

(Practically No Problem)

Dioxins Effective to Certain

Extent

Removal Effect Expected

Installation Area

Compared to System

on the right, it required

more space for

installation and greater

floor face load

Compared to System on the

left, it required less space.

Maintainability

Operability

Due to complicated

system and structure,

troubles like corrosion

occur

Due to simple system and

structure, failures occur less

frequently

Repairing

Easiness

Repairing takes time

and labor as Fume

Repairing takes less time

and labor, as system and


159

Figure 6-1 BF＋Wet-type System

Figure 6-2 Dry-type＋BF System

cleaning tower / White

smoke prevention

equipment/ Fume

cleaning water

treatment equipment

are easily corroded

structure are simple and not

corrosive


160

421. Based on the treatment flow incineration residue generation mechanism and

its properties in incineration plants are shown in Table 6-2 and Figure 6-3.

Table 6-2 Residue Generation Mechanism and its Properties

Generation

Mechanism etc.

Type

Generation Mechanism Generation

Amount Risk of Elution

Necessity

of

Treatment

Slag

Cinder or combustion residue

composed of the non-volatile,

non-combustible (glass bottle,

cans) and small amount of the

uncombusted of waste

5 - 10% of wet

weight of waste

(dry weight)

Although analysis

data of slag only is

not available,

elution risk is

assumed to be low

when generation

process is

observed. If it is

mixed with boiler

dusts, however,

there is a risk of

elution of Pb and

Zn.

△

Boiler Dust

Acidic gases (e.g. HCL or SOX)

and volatile heavy metals

generated from high

temperature combustion are

either reacted with alkali dusts

(e.g.Na2O or CaO) or

condensed into dusts during the

exhaust cooling process of

boiler.

Out of such dusts, the one

collected at the inertia force

dust collector is the boiler dust.

Unknown

(Almost the

same amount as

collected dust

though it varies

depending on

the structure of

inertia force dust

collector)

○

Collected Dust

1 - 1.5% of wet

weight of waste

(dry weight)

Cd

Pb, Zn

○

Fume Cleaning

Sludge Sulfide or hydroxide sludge that

forms when exhaust gas is

treated with wet-type alkali

cleaning and the wastewater is

added with sodium sulfide.

Also generated is waste chelate

and waste activated carbon that

are adsorbed with Hg.

Sludge amount

is basically

proportional to

the injected

amount of

coagulant.

Risk of Hg elution

○

Waste

Activated

Carbon

◎

Waste

Chelate ◎

Waste Water

Treatment Sludge

Mainly hydroxide sludge formed

by treating ash sewage with salt

iron. Carbonate sludge forms if

exhaust gas neutralization

treatment is conducted.

Almost no risk of

elution △


161

Figure 6-3 Ash and Residues Generated during MSW Incineration

422. In Japan, the boiler dust and the collected dust are both managed as

“specially controlled municipal solid waste”. This is why many fly ash detoxification

technologies have been developed so far. Responding to the above situation, many

ash solidification technologies have been developed. The outline is shown in Figure 6-

4.

Figure 6-4 Classification of ash treatment technologies


162

6.1.1.2 Fly Ash Generation Ratio

423. The fly ashes generation ratios in the basic waste incineration flow (stoker

method) in the previous section and in the other methods in Japan are shown below.

Tab 6-3 shows the ratio ash per wet-based waste amount assuming that the ash is 8%

of the accepted waste.

Table 6-3 Fly Ash Generation Ratio

Method Type Slag Generation

Ratio (%)

Fly Ash Generation

Ratio(%)

Stoker Method

Dry-type Exhaust Gas

Treatment 7 2

Wet-type Exhaust Gas

Treatment 7 1

Fluidized Bed

Method

Dry-type Exhaust Gas

Treatment 3 5

Wet-type Exhaust Gas

Treatment 3 1

Incineration＋

Ash Melting

Method

１-Stage Bag Filter Slag

5

Molten Fly Ash 0.4


2

Gasification

Melting

Method

Fluidized Gasification Slag＋ 5 2

Kiln-type Gasification Slag＋ 6 2

Shaft Furnace Type Slag

8 2

6.1.1.3 Properties of Fly Ashes

424. Since properties of the fly ash are influenced by such factors as waste quality,

incinerator type, incineration conditions, exhaust gas treatment method and dust

collection method, the chemical composition of fly ashes varies substantially.

425. The result of a measurement of heavy metals in fly ashes (conducted by

Japan Waste Research Foundation) categorized by the incineration methods is shown

in the following Table 6-4.

Table 6-4 Measurement Result of Heavy Metals in Soot and Dusts (unit: mg/kg)

Items

Fluidized Bed Method Stoker Method

Average Continuous

Combustion

Type

Semi-

Continuous

Type

Continuous Type Semi-

Continuous

Type


163

Boiler Type Boiler Type Water

Injection Type

Boiler

Water

Injection

Type

149 t

or

less

150 t

or

more

149 t

or

more

150 t

or

more

149 t

or

less

150 t

or

more

149 t

or

less

Cd

Pb

Zn

T-Cr

As

T-Hg

21

1,900

3,900

210

4

1

26

1,900

4,200

400

18

1

164

3,037

18,500

436

34

7

170

436

11,300

428

29

8

11

517

1,480

―

7

125

3,350

10,300

180

7

5

106

4,350

2,040

8

19

82

2,840

―

250

9

3

42

990

―

2,100

―

83

2,147

7,389

502

16

3

Note: As each value is rounded off to the nearest integer, the average values are different from those in the

original table.

426. As indicated the above table, fly ashes contain many substances in

concentrated manners in the waste while they have such common properties as small-

size particles, high dustability, or high absorbability. For the sake of easier handling, it

is often the case to put both slag, which has higher moisture content, and fly ash on

the same treatment line.

427. It has been pointed out, however, that fly ash may contain heavy metals that

have lower boiling points than the combustion temperature, and it may also contain

hazardous substance such as dioxins. Attention has been paid with great concern over

the management to prevent secondary pollution since re-elution phenomenon of

amphoteric heavy metals contained in the fly ash is found inevitable as a result of lime

injection to suppress acid gas emission. Recently, salts contained in incineration

residue have also caused such a trouble as clogging of pipes in leachate treatment

process in various places.

428. Therefore, from the viewpoint of final disposal, the fly ash issue is a matter of

grave concern in terms of qualitative load though it is not as serious as quantitative

load posed by the slag. In some cases fly ash is handled separately from slag, but

such practice still contains problems including how to treat it after separation.

429. Tokyo Metropolitan Area, which generates slightly less than 10 % of the

amount of total burned waste in Japan, is considered as a case here. The average


164

amount of fly ash generation in a stoker type incinerator with 100t/day capacity is 1 -

1.5 t/day while that of slag is approx. 9 t/day. Therefore, in an incineration plant with

the waste accepting capacity of 600t/day, 6 - 9t of fly ash/day is mixed with 54 t of slag,

goes through clinker channel system and is disposed of in a landfill site.

6.1.1.4 Composition of Fly Ash

430. complete continuous stoker-type exhaust gas treatment method is indicated

in Table 6-5. The result of properties analysis of fly ashes generated from incineration

plants in Tokyo Metropolitan Area is shown in Table 6-6.

Table 6-5 Exhaust Gas Treatment Methods of Incineration Plants under Survey

Items Types of Waste Exhaust Gas Treatment Method

Number of Plants

A

Combustible

Waste

Wet-type Fume Cleaning 4

B Dry-type Calcium Carbonate 4

C Dry-type Slaked Lime 4

D Segregated

Waste Wet-type Fume Cleaning

1

Table 6-6 Properties of Fly Ash of Incineration Plants in Tokyo Metropolitan Area

Items Combustible Waste Segregated Waste

Wet-type

Fume Cleaning Sample Type Unit Wet-type

Calcium

Carbonate

Slaked

Lime

Moisture

Ignition Loss

Fixed Carbon

Carbon

Hydrogen

Nitrogen

Combustible sulfur

Total Sulfur

Chlorine

Fluorine

%

%

%

%

%

%

%

%

%

mg/kg

<0.1

4.5

0.11

2.38

0.10

0.07

0.14

2.08

13.8

999

<0.1

8.6

0.70

4.54

0.29

0.08

0.13

1.59

12.2

405

<0.1

6.7

0.33

4.26

0.21

0.12

0.20

1.24

10.6

589

<0.1

<0.1

0.01

1.56

0.16

0.16

0.10

0.89

7.35

541

SiO2

Al2O3

Fe2O3

TiO2

%

%

%

%

21.6

13.0

1.41

3.94

20.5

12.1

1.19

3.86

23.0

14.8

1.49

4.50

20.1

34.6

5.67

5.71


165

Items Combustible Waste Segregated Waste

Wet-type

Fume Cleaning Sample Type Unit Wet-type

Calcium

Carbonate

Slaked

Lime

CaO

MgO

K2O

Na2O

P2O5

%

%

%

%

%

18.4

4.41

7.60

6.75

0.93

20.4

3.95

6.24

5.55

0.97

20.7

4.51

4.34

4.66

0.84

11.2

2.76

1.20

3.93

0.38

Zinc

Mercury

Lead

mg/kg

mg/kg

mg/kg

15,200

2.93

3,140

8,030

3.98

1,710

8,330

2.02

1,630

31,100

0.346

8,330

*Adjusted ash is defined as wet-cleaned EP ash added with calcium chloride and slaked

lime, which is assumed as the ash captured by bag filter.

1) Composition

431. When fly ashes properties were compared, the fly ash resulted from

"segregated waste" was found to have higher content of aluminum and iron whereas

the ash of "combustible waste" was found to have no significant difference in its

properties regardless of the difference of plants or the exhaust gas treatment methods.

432. In the incineration plants operated by Public Cleansing Bureau of Tokyo

Metropolitan Government, slated lime or calcium carbonate is injected into the flue to

clean the exhaust gas, or scrubbers are employed to conduct fume cleaning. Recently,

however, majority of the plants have employed dry-type HCl treatment + bag filter

(+wet-type fume cleaner) to prevent generation of Dioxins.

2) Heat Characteristics

433. The melting point is ordered as; combustible waste < segregated waste <

adjusted ash. (Refer to Table 6-7).

434. An example of thermobalance and differential thermal analysis is indicated in

Figure 6-5. The fly ash of "combustible waste" has a component that tends to

evaporate around 800℃ and reduces approx. 20% by weight before reaching to 900℃.

Table 6-7 Thermofusion Characteristics

Item Combustible Waste Segregated Waste Adjusted Ash

Softening Point 1,200 - 1,230℃ 1,290℃ 1,330℃


166

Melting Point

Fluid Point

1,210 - 1,280℃

1,220 - 1,290℃

1,410℃

1,480℃

1,380℃

1,390℃

Figure 6-5 Differential Thermal Analysis

435. In a crucible text, it was observed that the melting point exists in the area

beyond 1,200℃, and it requires the temperature of 1,250℃ or higher to obtain the

fluidized state. This means that when the fly ash is to be melted and solidified,

approximate 20% of it evaporates and converts to exhaust gas or molten fly ash.

3) Fluidity

436. As indicated in Table 6-8, the fluidity reaches highest when caustic lime and

borax are added, 10% each, as melting aid, and second highest when borax or soda

ash is added. The targeted waste is combustible waste in both cases, and fluidity ratio

is defined as the following when tests are conducted for melting and fluidity state with

the addition of caustic lime, borax and soda ash as melting aids in a crucible test.

Fluidity Ratio=(Weight of amount flown out of crucible) ÷(Total amount of ash used)

Table 6-8 Result of Crucible Test (unit:%)

Temperature

℃

Wet-type Fume Cleaning Method Dry-type slaked Lime Method

Caustic

Lime

Borax Soda

Ash

Visual

Judgment

Fluidity

Ratio

Caustic

Lime

Borax Soda

Ash

Visual

Judgment

Fluidity

Ratio

1300

20

10

5

△

○

○

0

36.0

28.5

20

10

5

×

○

○

0

30.5

34.5


167

Temperature

℃

Wet-type Fume Cleaning Method Dry-type slaked Lime Method

Caustic

Lime

Borax Soda

Ash

Visual

Judgment

Fluidity

Ratio

Caustic

Lime

Borax Soda

Ash

Visual

Judgment

Fluidity

Ratio

10

10

10

10

5

5

20

10

20

○

○

○

○

○

29.0

42.5

37.0

32.0

30.5

10

10

10

10

5

5

20

10

20

○

○

○

○

○

31.0

41.3

36.5

31.0

16.0

1200

20

10

10

10

10

5

10

5

5

20

10

20

×

○ △

○

○ △

○

○

0

18.0

0

14.5

27.5

0

25.0

15.4

20

10

10

10

10

5

10

5

5

20

10

20

×

○ △ △

○ △ △ △

0

27.0

0

0

8.6

0

0

0

6.1.1.5 Relation with Slag Composition

437. Waste composing substances (the object of incineration) oxidize with high

temperature through the incineration process and are separated into the slag and high

temperature exhaust gas. Volatile substances in the high temperature exhaust gas are

either condensed in the exhaust gas cooling process or reacted with chemical agent

into dusts and are captured as boiler dust or collected ash. In the case of wet-type

exhaust treatment method, water-soluble substances in slag and fly ash are expected

to turn into sludge after transferring to ash cooling water. In the case of wet-type fume

cleaning, too, even more substances are to taken out as water treatment sludge. In

either case, with the advancement of exhaust gas treatment method, the importance

of dust treatment is certainly getting even greater. There is substantial dispersion

among data of chemical properties of fly ash that have been publicized nation-wide.

But such data clearly show that fly ash contains higher concentration of low-boiling

point inorganic substance than in slag, and mixed ash contains high concentration

distributed in the middle of slag and fly ash. The ratio of copper and iron is higher in

the slag as exception. But as a logical conclusion derived form the structure of stoker-

type incineration plant, most of other items centering around low-point-heavy metals

shift to fly ash.

438. Recent annual average data of slag, sludge and fly ash generated from the

incineration plants in Tokyo Metropolitan Area are shown by item as Table 6-9.


168

Table 6-9 Annual Average Value of Slag, Sludge and Fly Ash Generated from

Incineration Plants in Tokyo Metropolitan Area

Unit: Content: mg/kg Elution: mg/L

Items Slag Sludge Fly Ash

Content Elution Content Elution Content Elution

T-Hg

R-Hg

Pb

Cd

T-Cr

Cr6+

O-P

As

CN

PCB

Cu

Zn

F

pH

Moisture

I.L.

0.27

0.007

480

140

―

ND

4.0

0.9

ND

1,200

2,100

140

―

33.6%

3.7%

ND

ND

0.5

ND

―

ND

ND

ND

ND

ND

ND

0.5

1.0

12.0

―

―

500

0.016

8,300

93

640

―

ND

11

1.1

ND

1,900

11,000

7,500

―

66.5%

19.0%

ND

ND

ND

ND

―

ND

ND

ND

ND

ND

ND

ND

8.4

8.4

―

―

2.3

ND

2,400

130

350

―

ND

21

0.6

ND

1,000

12,000

1,200

―

ND

5.6%

ND

ND

7.0

0.28

―

0.40

ND

ND

ND

ND

ND

2.2

4.8

11.2

―

―

439. As motioned earlier, the incineration plans in Tokyo Metropolitan Area employ

the wet-type exhaust treatment method where slag and fly ash are contacted with

water for the purpose of eluting heavy metals in ash cooling tank. The slag and fly ash

are separated into slag and sludge after going through the wet-type exhaust treatment

and water treatment facilities, and end up in a landfill site. The numeric values of slag

and sludge are those of intact samples that are considered total properties of slag and

fly ash. The trend is clearly shown when the distributed balance by material is

observed taking note of boiling points.

440. An example result of recent incineration fly ash analysis is shown below in

Table 6-10. This is the data of fly ash when wet-type exhaust gas treatment and dry-

type or bag-filter exhaust gas treatment were employed in stoker-type incineration

plants. The fly ash generated from the fluidized-bed type incinerator is treated by dry-

type exhaust gas treatment. The data of slag is also included in Table as reference.


169

Table 6-10 Analysis Example of Fly Ash Properties

Note: Alkali added on Fly Ashes of Fluidized-bed and Bag-filter, but not of Stoker“Dust Treatment Manual for Specially Control General Waste” Edited by Japan Waste Research Foundation, Supervised by Water Supply Environment Div. Living Hygiene Bureau, former Ministry of Health and Welfare, Published by Chemical Daly News Co.,Ltd.(1993)

6.1.1.6 Waste Treatment Flow and Estimate of the Fly Ash Amount in Japan

(1) Estimate of the Fly Ash Amount

441. Estimates of fly ash generation amounts based on Japan’s Waste Treatment

Statistics of 2014 are shown in Figure 6-6 and below;

Ｃa 。％) 9.7 15.0 20.0 11.0

Ａℓ 。％) 6 7.6 3.1 6.5

Ｆe 。％) 0.92 3.2 0.91 4.4

a 。％) 3.7 1.9 2.4 1.1

Ｋ。％) 5.9 2.6 4.0 1.3

Ｃℓ 。％) 11.0 8.7 15.0 1.4

Ｓ 4 。％) 4.2 1.8 4.4 0.84

(mg/kg) 5800 6500 4800 5200

n (mg/kg) 340 1000 200 1200

Ｃu (mg/kg) 660 4100 380 2700

b (mg/kg) 3100 1400 790 1100

Ｚn (mg/kg) 10000 4400 2000 5100

Ｃd (mg/kg) 110 25 31 13

Ｈg (mg/kg) 23 0.66 3.8 0.19

Ａs (mg/kg) 28 8.3 12 6.5

Ｃr6+ (mg/kg) 2.4 ＜0.7 ＜0.7 ＜0.7

Ｃ (mg/kg) ＜0.「＜0.「＜0.「 0.9

Ｆ (mg/kg) 2200 2 690 290

注ストーカ炉飛灰カ添加な流動床炉飛灰とバグフタ灰カ添加あり

特別管理一般廃棄物いん処理マニュ旧厚生省生活衛生局水道環境整備課監修財団法人廃棄物研究財団編化学工業日報社発行成５

項目ストーカ炉飛灰流動床炉飛灰バグフタ灰ストーカ炉焼却灰Stoker Fl Ash Ite


170

Figure 6-6 Treatment and Recycling Flow of Waste Incineration Ash

Incinerated Amount of Combustible Waste 33.47 million t Incinerated Amount of Crushed Residue etc. 1.39million t Total Incinerated Amount 34.86 million t Incinerated Amount of Residue 4.19million t Fly Ash Generated Amount (Incinerated Amount of Residue × 20%) 840,000 t Recycled Amount of Incinerated Residue (Incinerated Amount of Residue × 23%) 970,000 t

(2) Estimates of Fly Ash Disposal and Recycling

442. Most of incineration fly ashes are disposed of in landfill sites after solidified

into cement or chemically treated according to the standard. There are such recycling

methods as melting treatment (by local government or private sector), water-

wash/cement method, baking method, and Non-ferrous Recovery at Smelter.

Recycling of fly ash is basically carried out with slag. Exceptionally, Non-ferrous

Recovery at Smelter treats only fly ash for recycling.

Landfill Amount of Incineration Residue 3.21million t Landfill Amount of Fly Ash(Landfill Amount of Incineration Residue x 20%) 640,000 t Recycled Amount of Fly Ash 235,000 t


171

6.1.2 Mainstream Technologies and Application

6.1.2.1 Mainstream Technologies

(1) Appropriate Disposal Methods

443. The incineration fly ash is categorized as “Specially Controlled Municipal Solid

Waste”. For this reason, it needs to go through a detoxification process according to

the Law. Four detoxification methods have been established as the following:

Cement Solidification, Chemical Solidification, Melting, Solvent Extraction

(by using acid solution)

444. Outlines of each treatment method are described in Table 6-11. By taking one

of the four methods of treatment, stipulated disposal standard is to be complied, and

then allowed to be landfilled. The Disposal Standard is explained in the latter part of

this Paper.

TA-8963 PRC Draft Final Report Chapter VI

Table 6-11 Comparison of Notified Four Methods

Method

Items Melting Solidification Method

Chemical Mixture Method Cement-Solidifying Method

Solvent Elution Method

(Liquid Chelate) Acid Extraction Exhaust Gas Neutralization

1. Principles

and

Characteristics of

Treatment

Technology

By using the thermal energy obtained from

combustion heat or electricity, the object of

treatment is heated and melted at 1,200 -

1,400℃ while the inorganic is turned to

glassy slag.

Mixture Technology to treat both

incineration ash and fly ash has been in the

stage of common practice while the

technology to treat fly ash is in

demonstration stage.

Heavy metals in fly ash are made reacted

with chelate compounds to be solidified. The

operation is easy and low-cost.

It suitable to recover metals from solidified

matters.

(Note: non-chelate chemical agent is found to

be insufficient in suppressing Pb elution.)

Making use of hydration reaction of cement,

high-strength solid matter is formed. With

easy operation, low initial cost, the

technology has been established to some

extent and most widely employed.

By suspending dusts in acid solution, heavy

metals are sufficiently eluted and turned to

insolubilized matters. Then they are treated

with scavenger.

By making contact with combustive exhaust

gas, heavy metals in fly ash are turned to

stable carbonate. As this method reuses

exhaust gas and ash washing water

generated from the incineration plant, it can

reduce the running cost.

2. Requirement for the Object

・Form Fly ash with no specified form same as right same as right same as right same as right

・Pre-treatment May be necessary depending on particle

diameter or composition

10 - 40 % of additive water is used to metal

ion elution. pH value shall be maintained at 6

- 10.throughout the mixture process.

Not required Adhesion or foreign matter entry must be

avoided in the storage tank.

Heavy metals can be completely eluted in

the fly ash melting process.

・Composition

(recommended

value)

Content ratio of metals, water, and

unburned substances may be restricted.

pH adjuster shall be added for strong-alkali

fly ash.

pH range of Fly ash: 10 -11

CaO: 30 - 60%

pH adjuster shall be added for strong-alkali

fly ash.

pH range of Fly ash: 10 -11

CaO: 30 - 60%

EP ash・Bag filter ash (CaO 30-

60%

pH 10or higher

EP ash・Bag filter ash (CaO 30-

60%

pH 10or higher

・Heat

Characteristics

Although most cases have not limit in

basicity, low temperature melting method

(e.g. burner method) may be used with the

use of melting point lowering agent.

Not specified Not specified Not specified Not specified

3. Outline of System

・Treatment

Standard

Dry ash (Wet ash for Cokes Bed Method) Dry ash Dry ash Dry ash Dry ash

・Temperature

Control etc.

Automatic temperature control is possible

throughout melting process.

Heating device shall be used for bridge

prevention in the ash storage tank.(60 -

100℃)



100℃)



100℃)

Heating device shall be used for

stabilization of pH control and bridge


100℃)



100℃)

・Treatment

Capacity

Unit: 50kg/h～8,000kg/h

Difference depending on methods


Space:2,000m2 400kg/h



Unit:50 - 500kg/h

Space: It requires 1.5 - 2 times larger the

space of cement solidifying method. 2-line-

system is desired for the sake of

maintenance.

Unit:50kg - 2,000kg/h


・Dynamic

Characteristics

Ease in start-up and stop: Easy

Tolerance for Load Fluctuation:b 50%～

Emergency Means: Stop supplying chemical

Ease in start-up and stop: A little difficult

Tolerance for Load Fluctuation 50%～

Emergency Means: Dice cleaning is

Ease in start-up and stop: Easy and short

time required. When is breaks down, all

loaded amount must be discharged out of

Ease in start-up and stop: A little difficult


Emergency Means: Stop supplying exhaust


Method





agent required when solidification equipment

stops.

Melting Tank and Reaction Tank.


Emergency Means: Stop supplying fly ash

and chemical agent

gas and fly ash

・Maintainability While there's difference in Fuel type or

Electricity type, regular inspection and

repair work of cinder notch are required in

any case . General lifespan of refractories

is more or less the same as that of

incineration furnace or shorter.

Casing Liners

Flange Liners

Rods

Timing Belts

Air Suspenders

Replacement of paddles, dices, dice-

attaching flanges, screw holders, gland

packing, oil seals, etc.

Every 6 months, melting tank, reaction tank,

stirrers, pumps dehydrator, etc. should be

inspected and maintained.

In case of Ca-rich wastewater, care should

be taken against clogging of pipes and

corrosion of equipment.

Consumables: Fly ash intermediate pump

Dehydration pump impeller

・Operability Slag Flush Method: Intermittent flush for

small quantity / Continuous flush

for large quantity

Cooling method: Water cooling, air cooling,

slow cooling

Curing Method: Curing not required

Kneading performance is important.

Curing Method: Conveyer curing method

Conveyer transport

Curing Method: Conveyer curing method

Forming is difficult if limestone ratio is high.

Extrusion forming type is most common.

Conveyer transport

Melting, stirring and pH adjustment are

important.

Maintenance of dehydrator is also

important.

Conveyer transport

Melting, stirring and pH adjustment are

important.

Maintenance of dehydrator is also

important.

・Others Economies of Scale;: Better heat efficiency As the chelate agent reacts not only on the

targeted heavy metals but also on other

heavy metals, the volume to add shall be

determined based on total amount of metal

ions.

Depending on the content of heavy metals

and salts, types of cement and appropriate

volume of additional water shall be

determined. Methods of mixing, granulating,

forming are selected to be most suited to

the property of the target objects.

4. Material Balance etc.

・Detoxification Though no heavy metals are eluted from

the slag, molten fly ash should be treated

properly.

Dioxin decomposition ratio is very high.

Elution Characteristics: Complied with Land-

Fill Standards

While salts are eluted, the risk of heavy metal

elution is relative low.

Dioxins cannot be decomposed.

Elution Characteristics: Complied with

Land-Fill Standards

Salts are eluted.

In the long run, the elution risk of heavy

metal and salts is high.



Land-Fill Standards

Salty wastewater is generated.

Elution risk is involved in the long run,

depending on the insolubilizing method of

heavy metals eluted in the solvent.


Though hydrochloric acid is a proper acid,

the use of sulfuric acid as well in a two-

stage process is commonly practice with

cost consideration.


Land-Fill Standards

Salty wastewater is generated.

Insolubility of heavy metals depends on the

degree of carbonate transformation ratio.

Elution risk is involved in the dehydrated

precipitate in the long run.


・Stabilization Long-time stability is maintained. Long-time risks are involved even though

relatively stable compared with cement

solidification method.

With possible cracks and break-up of the

solidified substances, long-term stability is

not guaranteed.

Approx.25% addition of cement is sufficient

to suppress elution.

Solidification intensity is 10kg/m2 or

lower.

Stability depends on the method of

Insolubilization.

Stability depends on chemical stability as

carbonate in the environment.

・Volume/Weight

Reduction Effect

Volume

Reduction

Weight

1/5 - 1/6

0.9- 1.0times

1/3- 1/5

1.2- 1.3times(with chelate liquid and water)

1/2.5 - 1/3

1.4 - 1.5time greater (including cement and

water)

1/3 - 1/4

0.3 - 0.5times (after separation)

1/4 - 1/5

0.5 - 0.6(after dehydration)

Parts Repla e e t

～ti e s /YearRepla e e t:

O e/Year


Method





Reduction

5. Attached Facilities

・Exhaust Gas

Treatment

Facilities

Bag filter+ Hazardous gas removal

equipment

Ventilators are required to handle hydrogen

gas emitted from fly ash.

Not required Ventilators are required to handle hydrogen

gas emitted from fly ash.

Ventilators are required to handle hydrogen

gas emitted out of the reaction of

amphoteric heavy metals contained in EP

ash treated jointly in incineration exhaust

gas treatment equipment.

・Waste water

Treatment

Facilities

Treatment of floor wash water: 0.5m3 t of

ash

Not required Treatment of floor wash water: 0.5m3 t of

ash

Extract Treatment: Treatment of heavy

metals and salts

In the case of employing ash cooling tank

method, ash sewage is utilized. That makes

it unnecessary to have dedicated

wastewater treatment facilities.

・Other facilities Melting Fly Ash Treatment Equipment Combustive Gas Detector Dust Collection Equipment Combustive Gas Detector Combustive Gas Detector

6. Utility Condition

Fuel Burning Type

Oil:200 - 300ℓ t of ash

Electricity:150- 180kWh t of ash

Electric Methods

Power: 700 - 1,200kWh t of ash

Both methods use water and chemical

agents as well.

Power: 25kWh t of ash

Water: 300m3 t of ash

Consumables: Casing liners, Flange liner,

Rods

Chelate: 30kg - 150kg/t of ash

Power30kWh t of ash

Cement:200kg t of ash

Water:0.2 - 0.3m3 t of ash

Consumables: paddles, dices, screw

packing, oil seals, etc.

Replacement: Once/ 1- 2 Year

Fly Ash Treatment Amount:5t Day

Power: Approx.20kWh day

Elution Water: Approx.25t day

Hydrochloric Acid: Approx. 0.5t day

sodium sulfide: Approx.1.0t day

Power:40kWh t of ash

Water:10m3 t of ash

Consumables: Fly ash intermediate pump,

dehydration pump impeller

Replacement: Once/Year

dewatering aid:0.25kg t of ash

7. Cost

Initial Cost

Running

Cost

Most typically ¥100 million t of ash

¥10,000 - ¥30,000/t of ash

Approx. ¥10 million - ¥1.5 million t of ash

Chemicals: ¥20,000 - 30,000 t of ash

Consumables: Approx. ¥3 million /Year

Approx.¥20 million - ¥30 million t of ash

Approx.¥3,000 - ¥5,000/t of ash

Consumables: Approx. ¥2 million /Year

Approx.¥100 million / t of ash

Chemicals : Apporx.¥20 million year

Approx.¥30 million - ¥40 million t of ash

Approx. ¥500/<t3/>t of ash

Consumables: Approx. ¥5 million /year

8. Others

Intermediate

Treatment Plant for

incineration ash

and fly ash

9 4

Fly ash dedicated treatment is the main

steam.

93


steam.

5


steam.


steam.

Source: Japan Waste Research Foundation


445. The most popular method out of these in Japan is Chemical Solidification.

The chemicals used for solidification are divided in to two types: inorganic type and

organic type. Typical inorganic chemicals include phosphoric acid which generate

hydroxyapatite and pyromorphite, which is insoluble, to suppress elution of metals like

lead. Typical organic insolubilizers are dithiocarbamate and piperazine to solidify

metals as insoluble chelate complex.

446. When the fly ash contains dioxins exceeding standard value (3ngTEQ/g), it

cannot be disposed of by landfilling. In such a case, it has to be treated by thermal

dechlorination or high-temperature decomposition by melting. A diagram of a thermal

dechlorination device is shown below as Figure 6-7.

Figure 6-7 A Thermal Dechlorination Device for Fly Ash

447. Fly ash needs to be stored separately from its generation stage at waste the

incineration plant (Principle of Separate Storage). When the fly ash is recycled outside

of the incineration plant, it has to be transported in a dedicated vehicle (like jet packer)

equipped with dispersion prevention.


(2) Recycling Method of Fly Ash

448. These five technologies have been established in Japan to recycle fly ash In

Japan:

Melting, Use as Cement Material, Making Eco-Cement, Baking, Non-ferrous Recovery at Smelter. Outline of each technology is shown below.

1) Melting Treatment

449. Melting treatment is a technology to melt and transform incineration ash into

slag and metal at high temperature of 1,300 ℃ or higher by utilize fuel or electric

energy. Outline of a typical melting technology is shown as Table 6-12 below.


Table 6-12 Ash Melting Method

Items Ash Melting Method Gasification Melting Method Baking Method

Electric Methods (Plasma Type, Arc Type,

Electric Resistance Type etc.)

Fuel Burning Type

(Surface Melting Type etc.)

Integrated Method (Shaft Furnace Type) Separation Method (Fluidized Bed Type,

Kiln Type)

High Temperature Type, Low

Temperature Type

Schematic

Diagram

Example of Plasma Melting Furnace (Single

Torch Type)

Source Points in Planning and Designing for

Waste Treatment Plant, 2006

Example of Rotary Type Surface Melting

Furnace

Source Points in Planning and Designing

for Waste Treatment Plant, 2006

System Flow Example of Shaft Type

Gasification Melting Furnace



System Flow Diagram of Shaft Type

Gasification Melting Furnace



System Flow Example of Baking Furnace

(High Temperature)

Source: Document prepared by the 4th

Advisory Committee on Demonstration

Survey Obligation in Recycling of Incineration

Ash and Contaminated Soil by Radioactive

Material Separation

Products ○Molten Slag

○Molten Fly Ash

○Non-meltable

○Iron (Recovered at Pre-Process)

○Molten Metal

○Molten Slag

○Molten Fly Ash

○Non-meltable

○Iron (Recovered at Pre-Process)

○Molten Slag

○Molten Fly Ash

○Molten Metal

○Molten Slag

○Molten Fly Ash

○Non-meltable (Debris etc.)

○Metals

○Gravel-like or Earth-and-Sand-like Product

○By-product or Dust

Outline It is a incineration ash melting system with

electricity as its heat source.

It is classified into AC Arc Type, AC/DC

Electric Resistance Type, Plasma Type, and

Induction Type according to the method of

heat energy reception.

It is commonly employed as attachment

facility in a municipally operated medium or

large-scale incineration plant with power

generation facility.

It is a incineration ash melting system

with fuel such as kerosene as its heat

source.

It is classified into Rotary Type,

Reflection Type, Radiation Type, Swirling

Flow Type, Cement Kiln Type, Coke Bed

Type, Fuel Oxygen Burner Flame Type

according to the forms of furnace.

It is commonly employed as attachment

facility in a municipally operated small-scale

incineration plant without power generation

facility.

It is a melting system where at first waste is

thermally decomposed, secondly the

generated combustible gas and char(carbide)

are combusted with higher temperature, and

finally the ash and non-combustible are

melted with the combustion heat.

It is a system where thermal decomposition

of waste, gasification and melting are carried

out in an integrated manner.

Either of these systems requires cokes and

oxygen (both of which require huge amount of

power), and secondary material such as LPG

and the like.

It melts the whole including incineration ash

and recover slag and metal (alloy composed

of iron and copper) separately.

It is a melting system where at first waste is

thermally decomposed, secondly the

generated combustible gas and char(carbide)

are combusted with higher temperature, and

finally the ash and non-combustible are

melted with the combustion heat.

It's a Separate System where thermal

decomposition/gasification and melting take

place separately.

Depending on the type of furnace where the

thermal decomposition/gasification take

place, it is classified as fluidized bed-type

gasification melting furnace or kiln-type

gasification melting furnace. Either one has

an independent melting furnace.

It recovers metals and debris in the thermal

decomposition/gasification furnace, then

mostly the char( carbide) only is melted.

It's a system where soil or incineration ash

is heated and baked before reaching the

melting limit in a rotary furnace such as

Cement Kiln.

High-temperature type conducts heat

process at 1,300℃ or above while Low-

temperature type does so between 1,000 -

1,200℃.

Dust(Baked sly ash) is generated. Gravel-

like or Earth-and-Sand-like Product is

obtained as effectively usable products.





Fuel Burning Type



Kiln Type)


Temperature Type

Characteristics The exhaust gas volume is smaller

compared to that of fuel burring type.

With the longer retention time in the

furnace after melting, slag and metal is better

separated.

With higher power consumption, it is

difficult to be employed without attached

incineration plant with power generation

facility.

It may require additional heating to prevent

clogging at the cinder notch.

It requires input ratio adjustment of slag

and fly ash and periodical removal of attached

ash to avoid troubles caused by attachment or

clogging of molten salts or dusts.

It is easier to operate and manage

compared to electricity type.

It requires large volume of fuel.

In the surface melting type, excessive

moisture content in incineration ash may

cause insufficient melting.

In the surface melting type, if the

retention time is not sufficient, high-quality

slag is not easily obtained.

It requires input ratio adjustment of slag

and fly ash and periodical removal of

attached ash to avoid troubles caused by

attachment or clogging of molten salts or

dusts.

It's a simple system where the waste, cokes

and limestone are fed from the top into the

furnace that are zoned in a descending

manner as drying, preheating, thermal

decomposition and melting.

Some types of the equipment do not

require preprocessing of waste.

As it uses cokes and LPG, it emits a little

larger volume of CO2 compared to the others

types.

Some type of equipment cannot discharge

slag continuously, where a human labor

needed to do this job.

If it purports to treat only incineration ash, it

requires larger amount of cokes and

limestone (as basicity adjuster to ensure

fluidity of slag) compared to the one for waste

treatment.

As the waste melts by itself with its own

energy, it requires less electricity or fuel

compared to the ash melting method.

As it can operate with low air ratio

(approx.1.3),the exhaust gas volume is

smaller compared to the ash melting method.

With the low consumption of electricity or

fuel, it emits lower volume of CO2 compared

to other methods.

It basically purports to treat combustible

waste, it cannot treat mixed waste including

incineration ash.

According to a demonstration experiment,

Cs can be reduced to the clearance level of

100Bq/kg or below by vaporization treatment.

With the Cs removal ratio of 99.9%, the

products from obtained from High-

Temperature Type can be utilized for variety

of purposes.

With the Cs removal ratio of 90% - 98%, the

products from obtained from Low-

Temperature Type can be utilized as

substitute for earth and sand.

From the viewpoint of chemical

composition and mineralogy, the products

obtained from high-temperature type are

similar to mineral slag or slowly cooled slag of

blast furnace.

Achievement in

Number of

Operation Cases

Total 41Cases

Achievement of 20t/day or over during

FY2002 - FY2016)

・70% of them use Plasma Type.

・Since Fiscal Year 2005, the attachment of

melting facility to a new Incineration plant has

been no more required to grant governmental

subsidy, introduction of the said facility has

substantially decreased in 2006 and

afterwards.

・In recent years, increasing number of cases

have suspended or discontinued operation

due to reduced expense of operation &

maintenance.

Total 8Cases


FY2002 - FY2016)

・90% of them use Surface Melting Type.

・ Due to the same reason, the introduction

of this type has substantially decreased in

2006 and afterwards.

・ In recent years, increasing number of

cases have suspended or discontinued

operation due to reduced expense of

operation & maintenance.

Total 35Cases


FY2002 - FY2016)

・Due to the same reason as the ash melting

method, the introduction of this type has


afterwards.

・Since 2006, Shaft type systems have still

been introduced though in small number.

Total 37Cases


FY2002 - FY2016)

・Due to the same reason as the ash melting

method, the introduction of this type has


afterwards.

・Since 2006, Fluidized bed type systems

have still been introduced in small number

while kiln type has virtually not introduced.

Total 5Cases

・As a high-temperature type, 2 cases have

introduced in eco-cement plants, both of

which have achieved more than ten-year

operation.

・ As a low-temperature type, 2 cases in

heavy metal contaminated soil treatment

plants and 1 case in a chemical weapon

treatment plant have achieved the

introduction.

Plant

Manufacturers

that achieved the

above operations

○Mitsubishi Heavy Industries Environmental and Chemical Engineering Co., Ltd. (MHIEC)

○TAKUMA CO., LTD. ○JFE Engineering Corporation

○EBARA Environmental Plant Co., Ltd. ○Hitachi Zosen Corporation

○Kawasaki Heavy Industries, Ltd. ○Kobelco Eco-Solutions Co., Ltd. etc.

○Hitachi Zosen Corporation

○Kawasaki Heavy Industries, Ltd.

Kubota Corporation

○UNITIKA LTD. ○TAKUMA CO., LTD. ○KYOWA EXEO Corporation etc.

○NIPPON STEEL & SUMIKIN ENGINEERING CO., LTD.

○JFE Engineering Corporation

○KAWASAKI GIKEN CO.,LTD etc.

<Fluidized Bed Type>

○Kobelco Eco-Solutions Co., Ltd.

○EBARA Environmental Plant Co., Ltd.


○Mitsubishi Heavy Industries Environmental and Chemical Engineering Co., Ltd. (MHIEC)

etc.

<Kiln Type>


○TAKUMA CO., LTD. etc.

○TAIHEYO CEMNT Corporation

○Kobelco Eco-Solutions Co., Ltd. etc.





Fuel Burning Type



Kiln Type)


Temperature Type

Acce

ptanc

e

Cond

ition

for

Contr

ol

Size of

acceptab

le object

Approximately 30 - 50mmor smaller

Remarks Some systems may accept a 350L

Drum 955H×700Φ

1,0000mm or shorter

Note Feeding Input Width80t/Day 2m×2m

High-Temperature Type: Accepted if

pretreated for av. particle diameter of 40μm

Low-Temperature: 500mm or below

Approx.150 - 120mmand smaller

Pulverization required for pretreatment

Approximately 30mmor shorter

Acceptab

ility of

Incinerati

on Ash

and the

like

Incineration Fly Ash: Acceptable up to 30% of

total incineration ash

Molten Fly Ash: Not Acceptable (no effect for

capacity reduction due to vaporization)

Incineration Ash: Acceptable Up to 20% of

Waste

Molten Fly Ash: Not Acceptable (No volume

reduction effect due to volatilization)

Incineration Ash: Acceptable

Molten Fly Ash: Not Acceptable(no effect for


Incineration Ash: Even Incineration Ash Only

Acceptable If Combustion Aid is Used.

Molten Fly Ash: Not Acceptable(no effect for


Incineration Fly Ash: Acceptable up to 30% of

total incineration ash

Molten Fly Ash: Not Acceptable (no effect for


Pulveriza

tion of

solidified

incinerati

on ash

required

?

Crushing Required

Remark Though not required for some

system, it is desired to shorten melting time.

Crushing Required

Note Crushing at least to fist-size

Crushing Required

Crushing Required Crushing Required

Basic

Perfo

rman

ce

Incinerati

on

Tempera

ture

Melting Furnace: Approx.1,400℃ or higher

Incineration Furnace: Aprox.850℃- 950℃

Melting Furnace: 1,700 - 1,800℃ High-Temperature Type: Approx.1,300℃ or

higher

Low-Temperature Type: Approx.1,000℃ -

1,100 or >℃


(Gasification Furnace: Approx.500 ℃ -

600℃)


Incineration Furnace: Aprox.850℃- 950℃

Fuel,

Power

Consum

ption per

ton

Approx.800 - 3,000kWh/t of Ash ave.

approx.1,400kWh/t of Ash

― High-Temperature Type: Approx.170-

200ℓ/to of Ash 100t/Day

Low-Temperature Type: Approx.160ℓ/t of Ash

― Approx.160 - 460ℓ/t of Ash av.

approx.290ℓ/t of Ash

Envir

onme

ntal

Frien

dline

ss

Volume

Reductio

n Ratio

Approx.2% based on data provided by

anonymous manufacturer)

Approx.11% (based on data provided by


Approx. 5% (based on data measured on

anonymous demonstration experiment)

Unknown Approx.10% based on data provided by

anonymous manufacturer

Concentr

ation

Ratio of

Radioacti

veCs

Approx.24times based on data measured on

anonymous real equipment)

Approx. 8 times (based on data provided by


Approx. 15times (based on data measured on

anonymous demonstration experiment)

Unknown Approx.10times based on data measured on

anonymous real equipment)

Reso

urce

Recy

cling

Ratio

Use of By-

products

Backfilling material, Aggregate for Asphalt

Pavement, Cement Secondary Product, Sub-

base Course Material and Others

Backfilling material, Aggregate for Asphalt

Pavement, Cement Secondary Product,

Sub base Course Material and Others

High-Temperature Type: sub-base,

embanking material, foundation improvement

material and others

Low-Temperature Type: Substitute for earth

and sand (Concrete aggregate etc.)

same as right same as right

Use of

Metals

Balance Weight Material, Non-ferrous

Materials, Material for Steel, Others

Balance Weight Material, Non-ferrous

Materials, Material for Steel, Others

―

same as right same as right

Stabil Number Treatment Technology for Plasma Type has Treatment Technology for Shaft Type has Treatment Technology for both High- Treatment Technology for Fluidized Bed Type Treatment Technology for Surface Melting





Fuel Burning Type



Kiln Type)


Temperature Type

ity of

Introducti

on Cases

been well established with high number of

operation cases.

been well established with high number of

operation cases.

Temperature Type and Low-Temperature

Type have been well established.

has been well established with high number

of operation cases.

Type has been well established with high

number of operation cases.

Cases of

Accident

No recent report on large accidents No recent report on large accidents No recent report on large accidents No recent report on large accidents except

the below

No recent report on large accidents except

the below

Remark Case between Kyoto City and

Sumitomo Heavy Industries, Ltd. is pending

in court now.

Construction and

Operation &

Maintenance

Costs

Maintenance

Cost

The cost of 3 methods: Incineration + Ash

Melting Furnace, Gasification Melting,

Incineration + Calcination are almost the

same.

same as right The cost of 3 methods: Incineration + Ash



same.

same as right The cost of 3 methods: Incineration + Ash



same.

Remark: 1.Volume Reduction Ratio=Generated Volume of By-product molten and calcination fly ash) /Targeted Treatment Volume

2.Concentration Ratio of RadioactiveCs=Concentration of RadioactiveCs in By-product molten and calcination fly ash / Concentration of Radioactive Cs in Targeted Treatment Object


181

450. There are melting treatment practices using electric furnaces operated by

private sector (Reductive Melting Group including Chubu Recycle Co.,Ltd). The

melting treatment produces slag, which can be used as sand or aggregate for civil

engineering material. Zinc and lead are further recovered at smelter out of molten fly

ash. At melting treatment plants run by local government, however, molten ash is

disposed of by landfilling after chelate treatment.

Figure 6-8 Treatment Flow of Chubu Recycle Co., Ltd


182

Figure 6-9 Annual Average of Material Balance in Resource Recovery of Chubu

2) Use as Cement Material

451. It is a technology for optimizing incineration ashes into cement material. To

produce 1 ton of cement, it requires 1,100kg of limestone, 200kg of clay and 100 to

200kg of other materials. Incineration ashes can be used as alternative to clay material.

According to Japanese Industrial Standard (JIS), chlorine content in a Portland cement

product should be 350ppm or lower. The incineration fly ash contains 10 to 20% of

chlorine compounds. When it comes to use incineration ash as cement material, it is

necessary to determine its mix proportion considering chlorine content in the final

product. Chlorine compounds have to be removed in advance by using proper method

such as water washing. For this purpose, ash-cleaning technologies have been

developed.

3) Eco-Cement Production

452. Eco-cement is a type of cement product that is manufactured from municipal

waste incineration ash as main raw material. Other kind of wastes such as sewage

sludge can be used as ingredients for eco-clinker, which is supplemented to finalize

the eco-cement product. 1 ton of eco-cement product has to be derived from at least

500kg of waste. Heavy metals included in municipal waste are separated and

recovered before turned into eco-cement. JIS for eco-cement has been established

since July 2002. Fly ash can be used as it is for eco-cement production. For eco-

Molten

Metals

5%

Molten

Metals

5%

Magne c

Separator DryerMagne c

Separator

Desalina on

Mel ng

Furnace

Desalinated

ma er

1%

Salts

4.5%

Evapora ve

water

15.5%

Molten

Ash

4.5%

Others

5%

Water

10%

Iron

5%

Molten

Stone

54%

Molten

Metals

5%

Raw

Material

toFeed

78.5%

Raw

Material

100%


183

cement production, however, conventional infrastructure for cement production is not

allowed to use, a dedicated plant has to be newly constructed and operated. A rapid

hardening eco-cement contains higher choline than the standard for ordinary cement,

so it is allowed only for non-reinforced concrete uses. In Tokyo Metropolitan Area,

there is an eco-cement plant as facilities for recycling bottom and fly ashes. The

processing flow of the plant is shown as Figure 6-10 below.

Figure 6-10 Concept Diagram of Eco-Cement Manufacturing

Figure 6-11 Eco-Cement System Flow


184

Figure 6-12 Tama Area Waste to Eco-Cement Plant

4) Sintering

453. Sintering generally means a thermal treatment for the purpose of sintering.

Sintering is a phenomenon where a group of solid particles is heated with temperature

lower than their melting point and transformed into a sintered compact, which is a high-

density matter. Incineration ashes are thermally processed with 1,000 to 1,100℃ to

evaporate chlorine and heavy metals until they form sintered compacts. These

products are utilized for surface course of pavements or crushed stone for mechanical

stabilization, etc. Usually baking method is not used as a treatment of fly ash only.

5) Metals Recovery at Smelter

454. It is a technology to recover and recycle non-ferrous metals from molten ash

generated out of incineration ashes melting treatment. The molten ash contains 2 to

12% of such metals as lead, cadmium, zinc, and copper, etc. These metals are

recovered as single elements at smelter by using non-ferrous smelting technology. At


185

smelters of mining companies, they accept incineration fly ash and molten fly ash to

recover and recycle metals like zinc and lead in their smelting process. Figure 6-13

shows a non-ferrous recovery flow at a smelter.

Figure 6-13 Processing Flow of Non-ferrous Recovery at Smelter

6.1.2.2 Application Situation

455. Application situation of the above mentioned technologies are shown as Table

6-13 below.

Table 6-13 Treatment Methods of Incineration Fly Ash in Japan

Treatment Methods No. of Facilities as of 2014

Non-ferrous Recovery at Smelter, Eco-cement

etc. 37

Chemically Processed 883

Cement-Solidification 67

Melting Treatment 46

No treatment (Sludge 154

Cement-Solidification 67

Chemical Treatment 696

Cement-Solidification+ Chemical 161

Melting＋Cement＋Chemical 13


186

Treatment Methods No. of Facilities as of 2014

Chemically Processed＋Others 26

Melting ＋Chemical Treatment 15

Melting ＋Chemical Treatment＋Others 1

Melting Treatment 17

Other (Including non-ferrous metal recovery at

smelter 37

No treatment 154

Blank 19

Total 1206

456. Recycled amount of fly ash estimated based on statistics of Japan (Table 6-14):

Table 6-14 Recycled Amount of Fly Ash Estimated Based on Statistics of Japan

Statistics on Recycling of Incineration Residue Estimate on Recycling of Fly Ash

Disposal by Landfilling Disposal by Landfilling

3.214million ｔ 77% 910,000 ｔ 17%

Melting Treatment by Local Government Melting Treatment by Local Government

568,000 ｔ 13.5% 113,000 ｔ 2.7%

Water-wash/ Use for Cement Material Use for Cement Material

308,000 ｔ 7.4% 61,000 t (1.5%)

Melting by Private Sector Melting by Private Sector

30,000 ｔ (0.7%) 12,000 t 0.14%

Sintering Treatment Sintering Treatment

30,000 ｔ (0.7%) 12,000 ｔ 0.14%

Non-ferrous Recovery at Smelter etc. Non-ferrous Recovery at Smelter etc.

37,000 t (0.9%) 37,000 t (0.9%)

(1) Melting Treatment

457. Usually fly ash alone is not melted for treatment. Mixed with slag, fly ash is

melted at high temperature and transformed into slag, which is utilized for civil

engineering materials. Approx. 2% of molten ash is generated out of this process.

Melting Treatment Amount(dry) − Molten Fly Ash Generated Amount ＝ Generated

Slag Amount 113,000ｔ


187

(2) Use as Cement Material

458. Some cement plants accept slag as cement materials while others accept fly

ash as well and use it as cement material after water washing. The size of an eco-

cement plant is usually one tenth of that of normal cement plant. Out of the 32 cement

plants in Japan, 5 plants, 1 water-washing facility and 2 eco-cement plants accept slag

from incineration plants. Total accepted amount in 2014 was 308,000 t, out of which

61,000 t was considered fly ash.

(3) Eco-Cement Making

459. In Tokyo Metropolitan Area, a cement company and a local municipality has

jointly set up and operated an eco-cement plant. Eco-cement is a product

manufactured with waste incineration ashes that should take up at least 50 % of the

total amount of its raw material. The product standard allows its chlorine content higher

than that of normal cement, which limits the rage of application.

As Raw Materials Slag＋Fly Ash 500 kg

Cement Products 1000 kg

(4) Sintering

460. Industry waste disposal businesses conduct recycling operation with their kiln-

type sintering furnaces. There are only 2 such facilities in Japan.

Sintering Treatment Amount 12,000 t

(5) Metals Recovery at Smelter

461. Fly ash generated from incineration treatment is mixed with molten fly ash

derived from melting treatment, and transferred to smelters to recover metal

components (zinc, lead etc.) for recycling.

Metals Recovery Amount 37,000 t

6.1.3 Policies, Laws, Regulations and Standards

6.1.3.1 Policies, Laws and Regulations


188

(1) Policy

462. Japan has a policy to ensure thorough control over hazardous substances on

the premise of compliance with the ratified Basel Convention. It maintains that the fly

ash should be treated with special consideration (as Specially Controlled Solid Waste)

since it is regarded as hazardous judged from its components included.

(2) Law

463. The Waste Disposal and Public Cleansing Law stipulates the control standard

for fly ash as follows:

Collected dusts and ashes generated from combustion of municipal waste

shall be designated as specially controlled waste and be disposed of in landfill

sites after going through detoxification treatment. The standard for final

disposal sites for municipal waste stipulates environmental and safety

requirements (such as impermeable liners and leachate treatment facility).

464. The Specially Controlled Municipal Solid Wastes are listed below:

Soot and Dust

Dust, Incineration Residue, Sludge

Mercury Waste

Infectious General Waste

PCB contained components

(3) Enforcement Regulation

465. Chapter 1, Article 2, Clause 24 of Enforcement Regulation No.35 under The

Waste Disposal and Public Cleansing Law provide standard for landfill. This Standard

is judged based on an elution test conducted under required conditions.

466. Table Chapter 1, Article 2 of Enforcement Regulation under The Waste

Disposal and Public Cleansing Law /Ministerial Ordinance for Specific Standard is as

follows:


189

Table 6-15 Ministerial Ordinance for Specific Standard

Parameter Standard Unit

Alkyl Mercury No Detection mg/l

Mercury 0.005 mg/l

Lead 0.3 mg/l

Arsenic 0.3 mg/l

Cadmium 0.09 mg/l

Hexavalent Chromium 1.5 mg/l

Selenium 0.3 mg/l

Dioxane 0.5 mg/l

Dioxins 3 ngTEQ／g

467. The method of elution test, preparation of solution, analysis method of

compounds are stipulated in Notification No.633 under Ministry of Health and Welfare

(December 28, 2000).

468. It is required to prepare documents to record the amount handled as specially

controlled solid waste including the once-a-year elution test result. Transport standard

is also set for prevention of dispersion.

469. The detoxification methods are also stipulated. Based on the Ministerial

Ordinance, the 4 methods below are specified;

Cement solidification Method, Chemical Additive Method, Melting

Method, Solvent(Acid etc.) Cleaning Method

5) The outlines of these methods have been shown previously.

6.1.3.2 Regulatory System and Institutional Framework

470. Outline of regulation and control on fly ash of municipal waste is shown as

Figure 6-14 and Figure 6-15. When the concentration of dioxins exceeds 3ngTEQ/g,

the ash is not allowed to be landfilled, the dioxins needs to be decomposed to be lower

than the standard value by thermal dechlorination treatment and fusion baking

treatment.


190

Figure 6-14 Control Flow of Fly Ash (Soot and Dust)

Figure 6-15 Dioxins Control Standards for Fly Ash Landfilling and Final Disposal

Site

6.1.3.3 Technical Methods, Guidelines and Standards

471. In Japan, technical requirements have been set based on the law for each

treatment technology. Table 6-16 below shows technical requirements (for fly ash

treatment facility, baking facility, etc.), and Table 6-17 for municipal waste final disposal

site. Besides, performance guidelines and its interpretation are available as referral

technical guidelines to assist local governments to introduce those facilities.

472. For products derived from fly ash, Utilization Standard for molten slag (JIS),


191

Cement Products Standard and Eco-Cement Products Standard, etc. is available. The

Eco-Cement has to use waste incineration residue at least 50% of the raw materials.

473. Standards for Normal Cement and For Normal Cement Products are shown

below:

Table 6-16 Technical Requirements for Fly Ash Treatment Facility, Sintering Facility

Table 6-17 Technical Requirements for Municipal Waste Final Disposal Site

6) JIS for Slag Products are as follows:

JIS A 5031 “Molten Slag Aggregate for Concrete Derived from Municipal Waste, Sewage Sludge” JIS A 5032 “Molten Slag for Road Derived from Municipal Waste, Sewage Sludge”

6.1.3.4 Implementation Procedures and Safeguarding Measure

474. The status has to be reported the measurement values once a year as for

compliance with detoxified fly ash landfill standard. The total amount of incineration

and generated fly ash including the generated amount of Incineration treatment residue

and the landfilled amount need to be reported to the Central Government via Local


192

Government in a designate format once a year. These data is statistically processed

and publicized by Ministry of the Environment as statistics of “Waste Treatment in

Japan”.

475. Some slag products derived from melting treatment are subject to JIS

depending on their uses. The facility that makes application for that must prove

conformity to the Standard by conducting quality analysis.

476. Acceptance Standards for fly ash recycling have been set according to the

type of facility. The compliance to those standards is mostly reported annually to the

authority.

6.1.4 Experiences and Lessons

477. Technology development has been made for fly ash treatment in Japan from

the viewpoint of hazardous waste control. Landfilling of fly ash is not allowed except in

control-type final disposal sites, which are equipped with environment protection

measures for the surroundings. Only when Landfill Standards for fly ash are satisfied,

disposal by landfilling is allowed, as they are clear of hazard. The following section

summarized the development history of fly ash treatment in Japan and lessons learnt.

478. As mentioned above, it is difficult to find location for landfill site in Japan due

to narrow land and high population density. Therefore, the technologies to reduce the

landfill waste to zero has been required from 1980s and each private company started

to develop melting technology for bottom ash and fly ash. At the same period, the

emission of dioxin from MSWI was a serious issue in this sector and dioxin control

technologies were actively developed including decomposition technology for dioxin in

fly ash. In 1990, the Ministry of Health and Welfare issued “Guidelines for preventing

the emission of dioxins from MSWI” and gathered solutions that could be implemented

technologically at the time.

479. In 1991, the fly ash from MSWI was designated as specially controlled waste

in amendment of The Waste Disposal and Public Cleansing Law. Under this law, direct

landfill disposal of MSWI fly ash was banned and MSWI fly ash for landfill disposal

should undergo an intermediate treatment specified by the Minister of Health and


193

Welfare, including 1) melting and solidification, 2) solidification by cement, 3)

stabilization using chemical agents or 4) extraction with acid or other solvent. Later,

calcination including eco cement was added as an intermediate treatment. After that

period, the development of melting technology for bottom ash and fly ash, eco cement

technology, gasification- melting technology was promoted. In 1997, Ministry of Health

and Welfare issued “Guidelines for preventing the emission of dioxins from MSWIs

(Revised)” and amended ordinances in the Waste Management and Public Cleansing

Acts to strengthen standards for the construction and maintenance management of

waste treatment plants. Furthermore, regulations on soot and dust were strengthened

in April 1998 by amendments to regulations in the Air Pollution Control Act.

480. In 2000, “Act on Special Measures against Dioxins was enacted. The standard

on dioxin content in fly ash was set as 3 ng-TEQ/g in the administrative provision of

specially controlled waste. From this year, the Ministry of Health and Welfare require

installing melting process to local government as a condition to receive the subsidy

from the Ministry when the local government constructed MSWI. At that time, the dioxin

concentration in fly ash from many MSWIs exceeded the standard.

481. This notification from the central government spread the combination of

incinerator and ash melting process or gasification & melting furnace. Many of them

started up, and consequently energy consumption and operating cost increased in

these facilities. After that, the performance of stoker type incinerator was improved and

the dioxin formation dramatically decreased. As a result, the dioxin concentration in

MSWI fly ash met the standard. After 2011, the importance of global warming

prevention is recognized more and more in the environmental policy and the

requirement to install melting process was greatly relaxed and virtually canceled by

another notification from Ministry of Environment. Therefore, ash melting process or

gasification & melting furnace tends not to be adopted in local municipalities which can

secure landfill treatment. As a result, stoker type incinerator becomes popular.

482. However, because some local governments cannot secure enough landfill site,

they continue to operate ash melting process or gasification& melting furnace. There

has been an assessment on melting treatment that bottom ash should be treated or

recycled separately as mixed melting is often the cause of many troubles on facilities.


194

483. Some local governments with their own ash melting process or gasification &

melting furnace try to obtain the Japanese Industrial Standard certification for the

produced melting slag to promote beneficial use of the slag and tackle to exploit

demand for use of the slag. Some local governments ask private ash recycling

companies to treat MSWI bottom ash and fly ash by paying expensive fee.

484. Private sector’s existing facilities should be fully utilized; there are private

electric furnace businesses such as mining company with smelting facilities that have

reductive melting technology with high expertise and engaged in waste recycling

business. Those facilities of major businesses should be utilized effectively.

485. Recycling ash into cement material is also promising. With the establishment

of fume cleaning technology, chlorine-containing fly ash can also be turned into cement

materials. Even though manufacturing eco-cement requires a dedicated plant

construction newly, it can be a viable business in urban areas, where ash generation

density is high, as long as high collection efficiency is ensured. In the future, the

capacity of ash recycling in private companies will increase and they will progress the

resource recovery from bottom ash and fly ash.

486. The cost of chelating agents used to detoxify generated fly ash before being

landfilled is considered financial burden. Chelating agents can cause Nitrogen-Oxide-

contamination of leachate from final disposal sites.

6.2 Europe


487. Incineration of municipal solid waste is one of popular technologies in waste

management of EU. The scale of use of incineration as a waste management

technique varies greatly from location to location. According to the Confederation of

European Waste-to-Energy Plants, in European Member States (MS) the variation of

incineration in municipal waste treatments ranges from zero to 56 per cent. Data

obtained from Confederation of European Waste to Energy Plants (CEWEP) stated

that 28% of Municipal Solid Waste (MSW) across the EU 28 is still landfilled, although

landfill gasses (methane) contribute significantly to global warming (equalling 25 times


195

CO2). Figure 6-16 below shows the treatment of municipal waste in Europe in year

2014. Table 6-18 shows the change of incineration treatment in European countries

from 1995 to 2014.

Source of Data: CEWEP

Date of extraction: 13 Dec 2016 20:39:21 CET

Hyperlink to the table: http://www.cewep.eu/information/recycling/m_1486

Figure 6-16 Treatment of Municipal Waste in European Countries in 2014

http://www.cewep.eu/information/recycling/m_1486

http://www.cewep.eu/information/recycling/m_1486


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Table 6-18 Changes of Incineration Treatment in European Countries

Source of Data: Eurostat Last update: 30.11.2016

Date of extraction: 13 Dec 2016 06:43:15 CET

Hyperlink to the table: http://ec.europa.eu/eurostat/tgm/table.do?tab=table&init=1&plugin=1&language=en&pcode=tsdpc240

488. Incineration means thermal treatment of waste in an incineration plant as

defined in Article 3(4) or a co-incineration plant as defined in Article 3(5) of the

Incineration Directive 2000/76/EC. Municipal waste can either be incinerated directly

or after pre-treatment operations. The latter refers especially to secondary fuel

produced of waste.

489. The following solid wastes are commonly produced during the incineration

process:

• ashes and/or slag

• boiler ashes

• filter dust

• other residues from the flue-gas cleaning (e.g. calcium or sodium chlorides)

• sludge from waste water treatment.

http://ec.europa.eu/eurostat/tgm/table.do?tab=table&init=1&plugin=1&language=en&pcode=tsdpc240



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490. The types and quantities of incineration residue arising varies greatly

according to the installation design, its operation and waste input.

491. The solid residues produced by a MSW incinerator are collected from the

bottom of the combustion chamber (slag: 15-25% by mass of the original MSW and

about 80-90% of the total residues) and from the devices from which the gases pass

before they are released to the atmosphere. The residues that are collected after the

chemical cleaning of flue gases are usually named as air pollution control (APC)

residues. The term fly ash is used to describe the ash that is entrained by the gases

outside the furnace and is collected before the chemical cleaning of the gases. Like

this, APC residue is sometimes distinguished from fly ash. But, generally, incineration

fly ash means APC residue.

492. For MSWI residues different groups of contaminants can be identified,

including metal ions, amphoteric metals, oxyanionic species as well as salts, which

display typical leaching patterns. The total content of such contaminants can even be

considerably different for the various residues from waste incineration, as shown in

Table 6-19. Organohalogen compounds are formed in during the incineration process.

Recently, bag filter system is commonly used as a dust collector. Because dioxins in

flue gas is mainly attached in the dust, the dioxins are removed at bag filter and

transferred to fly ash. Consequently, dioxins in fly ash are of great concern.

Table 6-19 Ranges of Total Content of Elements in MSWI Residues

Element Concentration (mg/kg)

Bottom Ash Fly Ash Dry/semi-dry APC Residues Wet APC Residues

Al 22,000-73,000 49,000-90,000 12,000-83,000 21,000-39,000

As 0.1-190 37-320 18-530 41-210

Ba 400-3000 330-3100 51-14,000 55-1600

Ca 370-123,000 74,000-130,000 110,000-350,000 87,000-200,000

Cd 0.3-70 50-450 140-300 150-1400

Cl 800-4200 29,000-210,000 62,000-380,000 17,000-51,000

Cr 23-3,200 140-1100 73-570 80-560

Cu 190-8200 600-3200 16-1700 440-2400

Fe 4,100-150,000 12,000-44,000 2600-71,000 20,000-97,000

Hg 0.02-8 0.7-30 0.1-51 2.2-2300

K 750-16,000 22,000-62,000 5900-40,000 810-8600

Mg 400-26,000 11,000-19,000 5100-14,000 19,000-170,000

Mn 80-2400 800-1900 200-900 5000-12,000


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Mo 2-280 15-150 9-29 2-44

Na 2800-42,000 15,000-57,000 7600-29,000 720-3400

Ni 7-4200 60-260 19-710 20-310

Pb 100-13,700 5300-26,000 2500-10,000 3300-22,000

S 1000-5,000 11,000-45,000 1400-25,000 2700-6000

Sb 10-430 260-1100 300-1,100 80-200

Si 91,000-308,000 95,000-210,000 36,000-120,000 78,000

V 20-120 29-150 8-62 25-86

Zn 610-7800 9000-70,000 7000-20,000 8100-53,000

Data taken from Management of municipal solid waste incineration residues, Waste Management 23 (2003) 61–88 IAWG (International Ash Working Group: A.J. Chandler, T.T.Eighmy, J. Hartle´n, O. Hjelmar, D. Kosson, S.E. Sawell, H.A. vander Sloot, J. Vehlow), In: Municipal Solid Waste Incinerator Residues, Studies in Environmental Sciences 67, Elsevier Sci., Amsterdam, 1997)

493. The main problem related to fly ash the potential release of contaminant to

the environment. Therefore, fly ash is regarded as one of hazardous waste. On the

other hand, because slag does not contain contaminant so much, utilization of slag is

popular in European countries.



494. Usually, fly ash and APC residues are treated prior to being landfilled. The

treatment techniques may be grouped in four categories (1) extraction and separation,

(2) chemical stabilization, (3) solidification and (4) thermal treatment.

495. Also, utilization of fly ash is observed in some countries. The cases are

introduced in 6.1.3 Experience and Lessons.

(1) Extraction and separation: The main purpose is to remove or recover heavy

metals and salts from the residues, mainly by using water or acids. This treatment

technique is typically relatively simple but the main disadvantage is the generation of

process water with high content of metals and salts.

(2) Chemical stabilization: The main purpose is to bind and immobilize pollutants in

the residue matrix. Various chemical stabilization processes have been developed

most of them involve the use of FeSO4, CO2, CO2 and H3PO4, H3PO4 and sulphides.

In most cases, these are simple and low cost processes which significantly improve


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the leaching properties of the residues. The main disadvantage is the generation of

metal and salt containing process water.

(3) Solidification: The main purpose is to physically and hydraulicly encapsulate the

residues by using, for example cement, asphalt and gypsum. The main advantages of

solidification techniques are a decrease of leaching and improvement of the

mechanical properties. The main disadvantages are that mass and volume increases

with the treatment and that the physical integrity of the product may deteriorate over

time resulting in increased metals leaching.

(4) Thermal treatment: Three major types of thermal treatment exist: vitrification,

melting, and sintering. These processes destroy dioxins and produce very stable

products with good leaching properties. The main disadvantage is their high cost.


496. The techniques are used to treat the residues so that landfill acceptance

criteria are fulfilled, but also various material related criteria may have to be fulfilled for

example in the case of utilization. The above techniques reflect different approaches

to meet these goals. The reason for development of these different types of techniques,

rather than using a single process worldwide, has been differences in local traditions,

regulations, market conditions, and political focus.

497. In almost all countries, some level of treatment of the residues are required

before further utilization or landfilling. A commonly applicable definition of what is an

acceptable level of “stabilization” does not exist as criteria and conditions differ in

European countries. The examples are introduced in 1.3 Experience and Lessons.

Treatment and stabilization of residues should, however, provide a residue quality

appropriate for the intended final destination, regardless whether the associated

criteria are environmentally or technically based.



498. The key policy for the disposal of all kind of waste and residues in EU is the

EU Landfill Directive (1999/31/EC) and the Council Decision (2003/33/EC). The

Directive is intended to prevent or reduce as far as possible negative effects on the


200

environment from the landfilling of waste, by introducing stringent technical

requirements for waste and landfills. It defines the different categories of waste

(municipal waste, hazardous waste, non-hazardous waste and inert waste) and the

three classes of landfills (landfills for hazardous waste, for non-hazardous waste and

for inert waste). The criteria for the acceptance of waste on each landfill class are set

out in the Council Decision (2003/33/EC). The Decision defines also the methods to

be used for sampling and testing of waste. The acceptance criteria are based mainly

on leaching tests prEN 14405 and EN 12457/1-4.

499. Fly ash and APC residues are categorized as hazardous waste and residue

management is regulated within this framework. The related Directive and Statutory

Order etc. are as follows.

(1) Waste Incineration Directive

479. The process of revising the Waste Incineration Directive is expected to start

around 2008. This may affect emission levels from incinerators and subsequently also

the composition of residues.

(2) Waste Framework Directive

480. The directive provides a definition of waste utilization. This primarily affects

import and export of fly ash in EU Member States. The current revision of the Waste

Framework Directive suggests a new and more concise definition of utilization and end-of-waste criteria. When we use the fly ash as a construction material, some

countries have the criteria. The revised directive may also allow more possibilities for

the mixing of hazardous waste fractions, provided that the environmental burden is not

increased.

(3) Landfill Directive

481. The criteria for waste acceptance at landfills are minimum criteria and MS may

define more stringent criteria. First, the Landfill Directive had to be applied for new landfills only, and since July 2009 even existing landfills have to fully comply with the

set requirements.

(4) Statutory Order on Transport

482. Exchange of fly ash between MS is regulated according to the Statutory Order


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on Transport. MS may define more restrictive standards for residue treatment, and may deny import/export of residues on this account.

(5) Statutory Order on POP

483. The statutory order on persistent organic pollutants (POP’s), including dioxins, regulates management of waste containing these compounds. For fly ash, the content

of dioxins/furans is relevant with a limit value of 15 µg/kg. Generally, fly ash is

anticipated to be below this limit, however in cases exceeding the limit dioxins should

be destroyed or the residues should be safely landfilled.

(6) Council Decision 2003/33/EC

484. In general, MS shall define criteria for compliance with limit values set. Fly

ash is a hazardous waste. Criteria related to hazardous waste are as follows.

Criteria for hazardous waste acceptable at landfills for non-hazardous waste:

This element contains the definition of stable, non-reactive waste, leaching limit values

for granular hazardous waste acceptable at landfills for non-hazardous waste and

other criteria such as the content in TOC (Total organic carbon), pH and ANC (Acid

neutralizing capacity). MS shall determine which of the test methods and limit values

shall be used. In addition, they shall set criteria for monolithic waste to provide the

same level of environmental protection, criteria to ensure sufficient physical stability

and bearing capacity and criteria to ensure that monolithic wastes are stable and non-

reactive.

Table 6-20 Leaching Limit Values for Hazardous Waste Acceptable at Landfills for Non-hazardous Waste

Components

L/S = 2 l/g L/S = 10 l/g C0

(percolation test)

mg/kg dry

substance

mg/kg dry

substance mg/l

As 0.4 2 0.3

Ba 30 100 20

Cd 0.6 1 0.3

Cr total 4 10 2.5

Cu 25 50 30

Hg 0.05 0.2 0.03

Mo 5 10 3.5

Ni 5 10 3

Pb 5 10 3

Sb 0.2 0.7 0.15


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Se 0.5 0.3 0.2

Zn 25 50 15

Chloride 10000 15000 8500

Fluoride 60 150 40

Sulphate 10000 20000 7000

DOC(*) 380 800 250

TDS(**) 40000 60000 -

(*)If the waste does not meet these values for DOC at its own pH, it may alternatively be tested at L/S=10 l/kg and a pH of 7.5-8.0. The waste may be considered as complying with the acceptance criteria for DOC, if the result of this determination does not exceed 800 mg/kg (A draft method based on prEN 14429 is available). (**) The values for TDS can be used alternatively to the values for sulphate and chloride.

Criteria for waste acceptable at landfills for hazardous waste: Criteria set

comprise leaching limits for granular waste and limits for LOI (Loss of ignition), TOC

and ANC. This includes guidance for measurement and procedures in case certain

limits are exceeded. MS shall determine which of the test methods and limit values

shall be used and shall set criteria for monolithic waste to provide the same level of

environmental protection.

Table 6-21 Leaching Limit Values for Waste Acceptable at Landfills for Hazardous Waste

Components

L/S = 2 l/g L/S = 10 l/g C0

(percolation test)

mg/kg dry

substance

mg/kg dry

substance mg/l

As 6 25 3

Ba 100 300 60

Cd 3 5 1.7

Cr total 25 70 15

Cu 50 100 60

Hg 0.5 2 0.3

Mo 20 30 10

Ni 20 40 12

Pb 25 50 15

Sb 2 5 1

Se 4 7 3

Zn 90 200 60

Chloride 17000 25000 15000

Fluoride 200 500 120

Sulphate 25000 50000 17000

DOC(*) 480 1000 320

TDS(**) 70000 100000 -


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(*)If the waste does not meet these values for DOC at its own pH, it may alternatively be tested at L/S=10 l/kg and a pH of 7.5-8.0. The waste may be considered as complying with the acceptance criteria for DOC, if the result of this determination does not exceed 800 mg/kg (A draft method based on prEN 14429 is available). (**) The values for TDS can be used alternatively to the values for sulphate and chloride.

Criteria for underground storage: The major acceptance criterion for underground

storage is the site specific safety assessment as specified in Annex A. This safety

assessment has to prove the long-term isolation of the wastes from the biosphere,

taking into account e.g. local geological, geo-mechanical and hydro-geological

conditions during the operational and post-operational phase. In addition, quite a

number of wastes have to be excluded from underground storage due to associated

risks. MS may issue lists of wastes acceptable. The set criteria have to be fulfilled by

wastes under storage conditions. Furthermore, procedural requirements such as

secure separation from mining activities, classification in groups of compatibility etc.

have to be considered and addressed. There are specific regulations for salt mines

and hard rock formations. The limit values and criteria set in the corresponding landfill

have to be met at underground storage sites for inert and non-hazardous waste. The

compatibility with the safety assessment is the key criterion for underground storage

sites for hazardous waste. If compatible, acceptance criteria for hazardous waste

landfills do not apply. However, the waste must be subject to acceptance procedures

including basic characterization, compliance testing and on-site verification.


485. The regulatory system is different among countries, states and cities in EU. In

setting environmental standards, the prudence avoidance principle has been adopted

in Sweden. The ‘‘As Low As Reasonably Achievable” (ALARA) principle plays an important part in the enforcement of environmental law in the Netherlands. At the

European level, the ‘‘Best Available Technology Not Entailing Excessive Cost” (BATNEEC) principle is used . The details in major countries are described in

6.2.4Experiences and Lessons.


486. Sampling and test methods: Sampling and testing may only be carried

out by independent and qualified experts. Laboratories have to prove experience and

efficient quality assurance systems. In this context, MS can decide upon the

responsibility by selecting one of the two options. Furthermore, MS are obliged to draw

up sampling plans for basic characterization, compliance testing and on-site


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verification pursuant to the recently developed CEN (European Committee for

Standardization) sampling standard. Besides this, the methods set out in the decision

have to be used in general. As long as formal CEN standards are not available;

however, MS are allowed to use either national procedures and standards or the draft

CEN standard when this has reached the prEN stage. Tests and analyses for which

CEN standards are not yet available have to be approved by the competent authority.

487. prEN 14405 is a leaching behaviour test - Up-flow percolation test (Up-flow

percolation test for inorganic constituents). The batch leaching test EN 12457 consists

of 4 parts:

1. EN 12457-1: Performed at L/S 2 l/kg on material < 4 mm (1 step)


3. EN 12457-3: Performed at L/S 2 l/kg and L/S 8 l/kg on material < 4 mm

(2 step)


Digestion of Raw Waste

・ EN 13657 Digestion for subsequent determination of aqua regia soluble

portion of elements (partial digestion of the solid waste prior to

elementaryanalysis, leaving the silicate matrix intact)

・ EN 13656 Microwave-assisted digestion with hydrofluoric (HF), nitric

(HNO3) and hydrochloric (HCl) acid mixture for subsequent determination of

elements (total digestion of the solid waste prior to elementaryanalysis)

Analysis

・ ENV 12506 Analysis of eluates — Determination of pH, As, Ba, Cd, Cl, Co,

Cr, Cr(VI), Cu, Mo, Ni, NO2, Pb, total S, SO4, V and Zn (analysis of inorganic

constituents of solid waste and/or its eluate; major, minor and trace

elements)

・ ENV 13370 Analysis of eluates — Determination of ammonium, AOX,

conductivity, Hg, phenol index, TOC, easily liberatable CN, F (analysis of

inorganic constituents of solid waste and/or its eluate (anions))

・ prEN 14039 Determination of hydrocarbon content in the range of C10 to C40

by gas chromatography

6.2.3.4 Implementation Procedures and Safeguarding Measures

488. The implementation procedure is different among countries in EU.


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489. Member States shall take appropriate measures for implementation and

practical enforcement including the establishment of the necessary administrative and

technical infrastructure, permitting, operation procedures, monitoring and effective

control.

490. Basic procedure for the acceptance of fly ash at landfills is as follows.

Basic characterisation (function): The basic characterisation constitutes a full waste

description for the purpose of a save disposal, which is necessary for all types of waste.

The proceeding shall provide information on waste composition and its behaviour in

the landfill. Furthermore, it shall allow an assessment of waste against limit values and

a determination of key variables as well as the frequency for compliance testing.

Depending on the basic characterisation, the waste is accepted at the according landfill

class. The waste producer or, in default, the person responsible for its management,

is in charge to ensure that the information is correct. The Member States shall define

the period for the operator to keep records of the required information.

Fundamental requirement for basic characterisation: This section lists the

information necessary to fulfil the basic characterisation. Inter alia, it comprises

information on the waste production, composition, appearance, source and origin of

the waste.

Testing: Testing requirements are a crucial element of basic characterisation, which

can be regarded as a general obligation for each type of waste. The content of the

characterisation, the extent of laboratory testing and the relationship between basic

characterisation and compliance checking depends on the type of waste generation. It

is differentiated in regularly and not regularly generated wastes.

Cases where testing is not required: This section defines the cases where testing

of the waste is not required.

Compliance testing: Compliance testing has to be done periodically (at least once a

year) to check regularly arising waste streams. The relevant parameters to be tested

are determined in the basic characterisation. Compliance testing shall at least consist

of a batch leaching test and shall correspond to some of those used for basic

characterisation. Member States shall define the period for the operator to keep

records of the required information.

On-site verification: Each load of waste delivered to a landfill site shall be visually


206

inspected before and after unloading. Additionally, the required documentation shall

be checked. Member States shall determine the testing requirements for on-site

verification, and where appropriate rapid test methods. Furthermore, MS to determine

the period for sample keeping.


491. Italia, Netherlands, Denmark and UK cases for fly ash management are

introduced based on mainly ISWA report (2008) and Liu et al (2015).

6.2.4.1 Italy

a) Management Practices

492. Most of the waste to energy plants in Italy are equipped with a dry or a semi-

dry flue gas cleaning system, using lime or sodium bicarbonate as alkaline reactant. The use of sodium bicarbonate is now increasing, especially during the revamping of

existing plants, in order to comply with emission limits in the EU, without installing any

additional wet treatment system.

493. No thorough survey on the APC residues management has been carried out

so far in Italy. However, it is known that most facilities dispose of the residues to

landfills after a specific treatment. Treatment is mainly performed outside the incineration plant, but there are also some plants that treat APC residues on site.

494. Some Italian facilities, located in Northern Regions, export their untreated

APC residues to German salt mines as backfilling materials, similar to other European countries. There are nevertheless some examples of alternative forms of management.

For instance, in the case of using dry sodium bicarbonate the alkaline salts are

collected by the seller and treated in a plant having a capacity of 30,000 tons per year;

so a brine suitable for sodium carbonate production is recovered. This practice requires

a flue gas double stage filtration system, in order to pull apart alkaline salts from fly ash.

b) Specific Legislation

495. The Italian legislation (Government Decree n. 152/2006) classifies APC residues from waste-to-energy plants as hazardous waste according to the EU Waste

Catalogue. The Environment Ministry decree n. 36/2003 also prescribes that landfills can accept only waste whose contaminants content respect the limit values listed in

Table 6-22. Also a leaching test (according to the CEN EN 12457 standard) shall be


207

complied with; pollutant concentrations in extracted eluate shall not exceed the limits

shown in Table 6-23.

Table 6-22 Limit Values for Waste Acceptance in Landfill, as Per Decree N. 36/2003.



PCB mg/kg 50

PCDD&PCDF mg/kg 0.01

Solid content % ≥25

TOC % <6

Table 6-23 Limit Values in Eluate for Waste Acceptance in Landfill, as Per Decree

N. 36/2003


Cr mg/l 7

Cd mg/l 0.2

Cu mg/l 10

Hg mg/l 0.05

Mo mg/l 3

Ni mg/l 4

Pb mg/l 5

Sb mg/l 0.5

Se mg/l 0.7

Zn mg/l 5

Chloride mg/l 2500

Fluoride mg/l 50

Aromatic organic solvents mg/l 4

Nitrogen organic solvents mg/l 2

Chloro-organic solvents mg/l 20

Cyanides (CN) mg/l

Sulfates (SO42-) mg/l 5000

DOC mg/l 100

TDS mg/l 10000

c) Barriers and Challenges

496. At present it seems that there are no drivers pushing waste managers for

towards alternative options to landfill disposal, and it is unlikely that this will change in the near future. Possible use of APC residues in cement kilns or for construction

material are hampered by a strict and unclear legislation that makes recovery of

material from hazardous waste such as APC residues difficult and costly. Probably

only the recovery of alkaline salts from APC residues coming from plants that use

sodium bicarbonate will be further implemented, as it can partly overcome the issues

related to APC residues management. Also some thermal treatment methods were


208

evaluated and tested in the past, but they were abandoned, because there is no

chance that this technology can became commercially viable.

6.2.4.2 Netherlands

a) Management Practices

497. The Dutch policy with regard to incineration residues aims towards

maximization of useful application and minimization of required volume for disposal of

these residues. This policy has led, to date, to a recovery rate of the APC residues of

around 50%. The other half is disposed of in conditioned landfills after cementation (fly ash) or in big bags (fly ash and flue gas treatment salts). The policy has been put into

practice successfully for incineration fly ash and led to the use of this material as a filler in asphalt (as a substitute for lime stone) for road construction. The demand for asphalt

fillers containing MSWI fly ash, however, is limited. As a result only 30% of the MSWI

fly ash produced has been utilized as an asphalt filler. A considerable amount of fly ash and flue gas treatment salts are being utilized for fortification in German coal and salt mines (it has been adopted by the Council of State in the Netherlands that

application of APC residues is called utilization if it is identified as such in the country of application). The Dutch Waste Management Association (DWMA) has started a

project group which is going to identify potentially successful alternatives for fly ash utilization.

b) Specific Legislation

498. Annex II (Council decision 2003/33/EC) of the European Directive on the

Landfill of Waste (Directive 1999/31/EC) is implemented in Dutch legislation.

499. In addition, For solid waste to be reused as construction material, the solid

waste must meet the criteria as stipulated in the Dutch Building Materials Decree. From

1995 to 2008, the Dutch Building Materials Decree regulated the potential impact of

construction materials on the environment. It specified the environmental quality

criteria for the use of stony materials in construction, and did not distinguish between

primary, secondary, and waste materials. The regulations were updated in 2007 into

the Soil Quality Decree (came into force in July 2008). The reason for the revised

decree was to develop a simplified and more transparent regulation containing a

consistent set of emission limit values. There are limit values for monolithic and

granular construction products in the Soil Quality Decree (Table 6-24).

Table 6-24 : Emission Limits from the Netherlands Regulation as Part of the Soil Quality Decree


209

500. In general, these values are derived from impact modeling of groundwater and

soil quality, which are determined by ecotoxicological criteria. The emission limit values

for granular construction products were calculated in six steps, using leaching results

from tank leaching test carried out over 64 days. A generic average release pattern (in

mg/m2) for each inorganic substance based on a large collection of quality control data

for construction products was determined using the percolation test NEN 7343.

Geochemical modeling was then used to calculate how the substance concentrations

varied with time and depth of the soil. These substance concentrations were compared

with established compliance values at the point of compliance (POC). Point of

compliance is a location at some distance from a potential source of pollution where

some enforcement limit is set, measured and shall not be exceeded. The source

release was then adjusted to match exactly the compliance values in the soil and

groundwater at the POC. The adjusted substance releases from the source were then

transformed into emission limit values (in mg/kg). The more stringent emission limit

value of the soil or the groundwater was selected, for being protective of both the soil

and groundwater.

c) Barriers and challenges

501. Implementation of Annex II makes it more difficult (i.e. more costly) to landfill hazardous waste in its untreated form it’s already forbidden in the Netherlands. Since it is a waste of effort and money to continue with disposal Annex II serves as an

Monolithic Granular, open Granular, isolated

(mg/m2) (300 mm, mg/kg) (6 mm, mg/kg)

As 260 0.9 2

Ba 1,500 22 100

Cd 3.8 0.04 0.06

Cr 120 0.63 7

Co 60 0.54 2.4

Cu 98 0.9 10

Hg 1.4 0.02 0.08

Mo 144 1 15

Ni 81 0.44 2.1

Pb 400 2.3 8.3

Sb 8.7 0.16 0.7

Se 4.8 0.15 3

Sn 50 0.4 2.3

V 320 1.8 20

Zn 800 4.5 14

Br- 670 20 34

Cl- 110,000 616 8,800

F- 2,500 55 1,500

SO42- 165,000 1,730 20,000

Testing method NEN 7375 CEN/TS 14405

Element


210

incentive for more recovery of APC residues. This may lead to utilization of the

sulphates in the form of gypsum and chlorides in the form of calcium chloride.

6.2.4.3 Recovery and Utilization

502. Residues—or specific residue constituents—should always be utilized or

recovered if technically possible and environmentally beneficial. Based on the range of treatment techniques presented in 6.2.2 Main technologies and application, this is

feasible to a certain extent. Only a limited number of recovery and utilization solutions

exist today. One of the reasons for the lack of commercially available recovery and

utilization technologies is likely difficulties related to achieving satisfactorily technical

qualities of products based on fly ash and readily available virgin materials.

503. Recovery and utilization solutions are generally derived from and associated

with the treatment technologies. In many cases, the actual treatment processes are

integrated with the utilization solution.

(1) Recovery

504. Specific components present in the residues may be recovered and used again, for example in other industrial processes. The primary interest is centered

around metals and salts. Recovery is characterized by production of a material which

may substitute a similar virgin material and be used in a similar manner.

Salts

505. Evaporation of water from treated waste water from wet scrubbers can

produce a very concentrated salt solution, or recrystallized salt. This may be performed

by plants with no permission for discharge of waste water. Salt recovery directly from

the residues is also possible after water extraction of salts (i.e. “washing” of the residues). This has been considered in conjunction with several treatment technologies

generating salt containing process water.

506. Technology status: The technique is in commercial use.

Metals

507. From a technical point of view, residues represents low-grade ores that may

be subjected to metal recovery using traditional upgrading methods. This has, however,

only been attempted in a limited number of cases. Overall, metals are primarily

recovered based on two approaches:


211

・ Extraction techniques: mainly acid extraction

・ Thermal techniques: melting

508. Acid extraction is a well known method for dissolution of solid materials, and

provided pH is sufficiently low most metals will dissolve into solution. The recovery rate

is limited by the dissolution level, and the quality of the recovered metals by the solution

composition. The recovered metal product may need further upgrading before a

suitable quality is achieved.

(2) Utilization

509. APC residues have properties to some extent comparable with cement (e.g.

pozzolanic behavior and contents of Ca, S, Al, Si), and may be utilized as filler material or aggregates. However due to the high contents of easily dissolvable salts and a

potential for hydrogen generation, APC residues cannot directly substitute cement.

Utilization is characterized by substitution of materials in products or applications to

which the residues can contribute with useful properties.

510. Utilization of APC residues for the applications mentioned in the following

should always be associated with a detailed description of the residue amounts used,

the placement, and the fate of the residues in case of demolition of the involved

structures. Registration by the responsible authorities should be a prerequisite for

utilization.

Cement Based Applications

511. APC residues have been suggested to substitute cement in concrete for

construction purposes, for example construction elements for buildings, shore

protection blocks, and artificial reefs. While solidification of residues by addition of

cement is relatively simple, substitution of cement by APC residues in concrete can be

rather difficult.

512. Considering the technical limitations related to producing concrete products

with APC residues and the availability of cement, residue utilization as general

construction materials is not particularly widespread. APC residues are, however, used

as material for backfilling of mines to avoid collapse. This is done on a large scale in German salt mines. The properties of the residues used for utilization may be improved

by washing, either with water or acid. Although not with a focus on utilization, this has

been practiced in Europe with subsequent addition of cement in order to cast blocks

for landfilling.


212

Filler Materials

513. Investigations of coal fly ash utilization, and similar materials such as APC residues, as filler material has been carried out for many years, examples are embankments, highway ramps, noise barriers, harbour facilities, etc. Compared with

coal fly ashes, APC residues are much less suited for those purposes due to the high

contents of easily soluble salts resulting in potential problems with settling. However,

due to the pozzolanic properties of the residues, uptake of water can induce hardening

and result in a rather hard material over time.

514. Utilization of APC residues as filler material for construction works are generally not accepted today due to the environmental aspects, but may have been

practiced earlier.

515. Technology status: The technique is not commercially available.

Asphalt

516. Utilization of APC residues in bituminous structures has been investigated in

a number of cases, primarily with a focus to stabilize the residues and minimize

leaching. Fly ash can, however, be utilized as a substitute for filler material in asphalt production. Fly ash is used for this purpose in The Netherlands for road construction

on a regular basis: fly ash is ground, homogenized and mixed with other materials to produce a combined filler material with a maximum of about 25 % fly ash. Utilization of residues in asphalt production in The Netherlands is accepted on the premise that used

asphalt is recycled and the residues therefore are part of a closed loop.

Neutralization Capacity

517. The very alkaline nature of APC residues may serve as neutralization capacity

of acidic waste materials. This is utilized in Norway on acid waste from the titanium

industry. After neutralization, the remaining solid products are landfilled. Utilization of APC residues for neutralization purposes is also carried out in the United Kingdom.

6.2.4.4 Denmark

Denmark WAC, Statutory Order No. 252, and Statutory Order No. 1662

518. According to Statutory Order No. 252, and Statutory Order No. 1662, the EU

WAC Decision has been implemented in Denmark regulation by the Statutory Order

No. 252 of 2009. The Denmark EPA decided to use a similar modelling methodology


213

employed for the EU landfill directive, but adjusted for Denmark conditions. Denmark

relies heavily on groundwater as a source for drinking water, and therefore has a strong

incentive to strictly protect groundwater quality. Because of this, the Denmark

acceptance criteria should be more stringent than those set by the EU. Other

differences are that the Denmark POC is located 100 meters downstream of the landfill,

and the Kd values, used to describe the contaminant-subsoil interaction in the transport

modelling, have been adjusted for Denmark. In Denmark, landfills that are located

inland and those located near the seacoast are distinguished. Also, three

subcategories of landfills for non-hazardous waste are defined: landfills for mineral

wastes, mixed waste, and non-reactive hazardous waste. Furthermore, mineral waste

landfills are divided into three types: inland mineral waste landfills (MA0), seacoast

mineral waste landfills with higher dilution potential by the nearby sea (MA1), and

seacoast mineral waste landfills with lower dilution potential by the nearby sea (MA2).

Table 6-25 lists the leaching limit values for non-hazardous mineral waste.

Table 6-25 Waste Acceptance Criteria for Non-hazardous Mineral Waste in

Denmark

Waste

Category

MA0: Mineral Waste

Landfills Located

Inland

MA1: Mineral Waste

Landfills Located near

the Seacoast

MA2: Mineral Waste


the Seacoast with

Lower Dilution

Contami

nant

L/S=2l

/kg

L/S=1

l/kg

Co

percol

ation

test

L/S=2

l/kg

L/S=1

l/kg

Co

percol

ation

test

L/S=2

l/kg

L/S=1

0l/kg

Co

percol

ation

test

mg/kg mg/kg mg/l mg/kg mg/kg mg/l mg/kg mg/kg mg/l

As 0.082 0.37 0.04 0.4 2 0.3 0.4 2 0.3

Ba 9.5 28 5.5 30 100 20 10 30 6

Cd 0.072 0.11 0.06 0.6 1 0.3 0.6 1 0.3

Cr

(total)

0.36 1 0.2 4 10 2.5 1.5 4 1

Cu 5.9 13 4 25 50 30 15 35 10

Hg 0.012 0.05 0.0063 0.05 0.2 0.03 0.05 0.2 0.03

Mo 0.44 0.9 0.31 5 10 3.5 5 10 3.5

Ni 0.22 0.5 0.14 5 10 3 5 10 3

Pb 0.28 0.6 0.18 5 10 3 5 10 3

Sb 0.022 0.08 0.012 0.2 0.7 0.15 0.2 0.7 0.15

Se 0.17 0.31 0.12 0.3 0.5 0.2 0.3 0.5 0.2

Zn 2.1 5 1.4 25 50 15 25 50 15

Cl- 2,000 2,900 1,700 10,00

0

15,00

0

8,500 10,00

0

15,000 8,500

F- 13 33 8 60 150 40 60 150 40


214

Waste

Category

MA0: Mineral Waste

Landfills Located

Inland

MA1: Mineral Waste


the Seacoast

MA2: Mineral Waste


the Seacoast with

Lower Dilution

Contami

nant

L/S=2l

/kg

L/S=1

l/kg

Co

percol

ation

test

L/S=2

l/kg

L/S=1

l/kg

Co

percol

ation

test

L/S=2

l/kg

L/S=1

0l/kg

Co

percol

ation

test

mg/kg mg/kg mg/l mg/kg mg/kg mg/l mg/kg mg/kg mg/l

SO42- 2,600 5,200 1,800 10,00

0

20,00

0

7,000 10,00

0

20,000 7,000

Testing

method

EN

12457-

1

EN

1245

7-2 or

CEN/

TS

1440

5

CEN/T

S

14405

EN

1245

7-1

EN

1245

7-2 or

CEN/

TS

1440

5

CEN/T

S

14405

EN

1245

7-1

EN

12457-

2 or

CEN/T

S

14405

CEN/T

S

14405

519. Beyond the characterization of waste for different landfills, Denmark’s Statutory Order No. 1662 (2010), ‘‘Utilization of Residual Waste Materials and Soil for Construction Works and Utilization of Sorted, Unpolluted C&D Waste,” sets leaching

criteria that apply to residual products (MSWI BA, BA and FA from coal fired power

plants) and soil. The criteria are listed in Table 6-26.

Table 6-26 Limit Values for Content and Leached Amounts in Statutory Order

1662/2010

Substance Category 1 (mg/kg) Category 2 (mg/kg) Category 5 (mg/kg)

Total element content in dry matter

As 620 >20 >20

Cd 60.5 >0.5 >0.5

Cr (total) 6500 >500 >500

Cr (VI) 620 >20 >20

Cu 6500 >500 >500

Hg 61 >1 >1

Ni 630 >30 >30

Pb 640 >40 >40

Zn 6500 >500 >500

Leachate amount at L/S=2L/kg

Chloride 6300 6300 300-6,000

Sulfate 6500 6500 500-8,000

Na 6200 6200 200-3,000

As 60.016 60.016 0.016-0.1


215

Substance Category 1 (mg/kg) Category 2 (mg/kg) Category 5 (mg/kg)

Total element content in dry matter

Ba 60.6 60.6 0.60-8.0

Cd 60.004 60.004 0.004-0.080

Cr 60.02 60.02 0.020-1.0

Cu 60.09 60.09 0.090-4.0

Hg 60.0002 60.0002 0.0002-0.002

Mn 60.3 60.3 0.30-2.0

Ni 60.02 60.02 0.020-0.14

Pb 60.02 60.02 0.02-0.20

Se 60.02 60.02 0.020-0.060

Zn 60.2 60.2 0.2-3.0

Testing method EN12457-1, L/S =2L/kg

520. Soil and residues to be utilized are classified into three different categories,

based on the determination of trace element content after partial digestion with 7 M

nitric acid, with different applications. Category 1 may be used for certain specified

purposes, i.e. construction of roads, paths, parking lots, noise reduction walls, ramps,

dikes, dams, railway embankments, pipe/cable trenches, landscaping, marine

constructions, refilling floors and foundations. Categories 2 and 3 are for the reuse of

contaminated waste for geotechnical purposes. Moreover, Category 2 is for roads,

paths, cable trenches, floors and foundations, noise banks, and ramps, whereas

Category 3 is for roads, paths, cable trenches, and floors and foundations. Both

Category 2 and Category 3 residues and soil may be recycled under increasingly more

stringent conditions concerning the type of application, thickness, and top cover. If the

analysis result from the leachate meets the criteria for the category, the use is suitable

for that category.

6.2.4.5 The Netherlands

Netherlands Soil Quality Decree

521. The Netherlands approach to waste management, also known as the

‘‘Lansink’s Ladder,” is to: avoid as much waste as possible in the first place, recover reusable resources from wastes, generate energy through waste incineration, and then

dispose the remaining waste into landfills. In keeping with the practice of recovering

reusable resources from wastes, stony wastes can be reused in construction

applications. For solid waste to be reused as construction material, the solid waste

must meet the criteria as stipulated in the Dutch Building Materials Decree. From 1995

to 2008, the Dutch Building Materials Decree regulated the potential impact of


216

construction materials on the environment. It specified the environmental quality

criteria for the use of stony materials in construction, and did not distinguish between

primary, secondary, and waste materials. The regulations were updated in 2007 into

the Soil Quality Decree (came into force in July 2008). The reason for the revised

decree was to develop a simplified and more transparent regulation containing a

consistent set of emission limit values. There are limit values for monolithic and

granular construction products in the Soil Quality Decree (Table 6-27).

Table 6-27 Emission Limits from the Netherlands Regulation as Part of the Soil

Quality Decree

Element Monolithic Granular, open Granular, isolated

(mg/m2) (300mm, mg/kg) (6mm, mg/kg)

As 260 0.9 2

Ba 1,500 22 100

Cd 3.8 0.04 0.06

Cr 120 0.63 7

Co 60 0.54 2.4

Cu 98 0.9 10

Hg 1.4 0.02 0.08

Mo 144 1 15

Ni 81 0.44 2.1

Pb 400 2.3 8.3

Sb 8.7 0.16 0.7

Se 4.8 0.15 3

Sn 50 0.4 2.3

V 320 1.8 20

Zn 800 4.5 14

Br- 670 20 34

Cl- 110,000 616 8,800

F- 2,500 55 1,500

SO42- 165,000 1,730 20,000

Testing

method

NEN 7375 CEN/TS 14405

522. In general, these values are derived from impact modeling of groundwater and

soil quality, which are determined by ecotoxicological criteria. The emission limit values

for granular construction products were calculated in six steps, using leaching results

from tank leaching test carried out over 64 days. A generic average release pattern (in

mg/m2) for each inorganic substance based on a large collection of quality control data

for construction products was determined using the percolation test NEN 7343.

Geochemical modeling was then used to calculate how the substance concentrations


217

varied with time and depth of the soil. These substance concentrations were compared

with established compliance values at the POC. The source release was then adjusted

to match exactly the compliance values in the soil and groundwater at the POC. The

adjusted substance releases from the source were then transformed into emission limit

values (in mg/kg). The more stringent emission limit value of the soil or the groundwater

was selected, for being protective of both the soil and groundwater.

6.2.4.6 UK

523. The legal provisions dealing with these points are in the Environmental

Permitting (England and Wales) Regulations 2010 (as amended) (EP Regulations),

the Landfill Directive (1999/31/EC) and the Council Decision (2003/33/EC). Before a

waste can be accepted at a landfill site, the landfill operator must be satisfied that the

waste meets his permit conditions, the waste acceptance procedures (WAP) and

waste acceptance criteria (WAC).

Leaching Limit Values

524. The leaching limit values relate to specific leaching tests. The limits and tests

are different for granular and monolithic wastes as shown in Table 6-26 and 6-27. For

monolithic waste, blocks of the waste of specified dimensions are held in a tank of

eluate for a period of time. The leaching of constituents is a function of the surface

area of a monolith. The results are specified as milligrams per square metre. Note:

monolithic wastes can be crushed and tested as granular waste using the granular

waste limits.

Definition of Monolithic and Granular Wastes

525. A monolithic waste is a waste that has been deliberately treated to solidify it

and strongly bind it. Granular wastes include all wastes that are not monolithic.

Landfill Waste Acceptance Criteria for Granular Wastes

526. The Regulations state that granular waste can be considered to be any waste

that is not monolithic waste. Quantitative limit values have been set for regulating the

chemical characteristics of granular wastes accepted into landfills for hazardous waste,

cells within non-hazardous sites for stable non-reactive hazardous waste and inert

waste landfills. WAC have not currently been set for non-hazardous waste landfills.

527. Where landfill acceptance criteria cannot be met, information from leaching


218

behaviour tests undertaken as part of the Level 1 characterisation, can help to make

an informed decision about waste treatment that will allow landfill or other alternative

management options. Leaching behaviour tests include the maximum availability

leaching test, pH dependence test and upflow percolation test. As a minimum,

information will be needed to classify the waste as a hazardous or non-hazardous

waste and to identify the class of landfill at which it may be disposed. As most

hazardous wastes will require treatment prior to landfilling, this classification and

assessment of acceptability will usually be on treated wastes.

Waste Classification

528. The Landfill Regulations require the waste producer to classify his waste as

hazardous or non-hazardous waste as part of the basic characterisation. This is

provided for by:

a) the code applicable to the waste under the European Waste Catalogue11;

b) in the case of hazardous waste, the relevant hazard properties according to

Appendix III of the Hazardous Waste Directive (91/689/EEC).

529. Wastes are classified as hazardous or non-hazardous wastes on the basis of:

(a) European Waste Catalogue (EWC) coding. The EWC (2002) lists wastes by

industry sector.

It defines wastes according to their known hazard characteristics, as:

− hazardous (absolute);

− mirror-entry (hazardous or non-hazardous depending on the presence of

hazardous properties/dangerous substances);

− non-hazardous wastes.

Note: the EWC does not define inert wastes.

(b) Hazard assessment. The presence or absence of the 14 hazard properties listed

in the Hazardous Waste Directive (91/689/EC) (e.g. H4 irritant, H6 toxic, H14

ecotoxic) defines a mirror-entry waste as hazardous or non-hazardous respectively.


219

Table 6-28 Limit Values for Compliance Leaching Test for Granular Waste from


Parameter and

Substances

Inert Waste Stable Non-Reactive

Hazardous Waste in

Non-hazardous

Hazardous

Waste

BS EN 12457-3 Limit Values (mg/kg) at L/S=10l/kg

As 0.5 2 25

Ba 20 100 300

Cd 0.04 1 5

Cr 0.5 10 70

Cu 2 50 100

Hg 0.01 0.2 2

Mo 0.5 10 30

Ni 0.4 10 40

Pb 0.5 10 50

Sb 0.06 0.7 5

Se 0.1 0.5 7

Zn 4 50 200

Cl- 800 15,000 25000

F- 10 150 500

SO42- 1000 20000 50000

Total Dissolved

Solid (TDS)

4000 60000 100000

Phenol index 1

Dissolved Organic

Carbon (DOC)

500 800 1000

530. Total dissolved solids (TDS) is not a primary parameter. There is no

requirement to meet the limit value for TDS unless the waste holder has opted to do

so in preference to meeting the individual chloride and sulphate limits. It may be used

as an optional replacement for chloride and sulphate leaching values, particularly if a

waste is unable to comply with the chloride and sulphate limits individually but is able

to meet the TDS values. The UK did not agree to the leaching test criteria for cadmium

and mercury for non-hazardous and hazardous waste sites and proposed lower limit

values of 0.1 and 1 mg kg-1 Cd and 0.02 and 0.4 mg kg-1 Hg respectively. Following

consultation of the Landfill (England and Wales) Amendment Regulations 2004, the

EU limits for Cd and Hg have been applied.

Landfill Waste Acceptance Criteria for Monolithic Waste

531. Monolithic wastes will normally mean wastes that have been deliberately

treated to solidify them. These requirements would apply to any monolithic material,


220

be it cementaceous or otherwise, but provided that the waste is disposed of to form

large blocks or slabs and not as a simple mixed stabilised waste (e.g. as cement

stabilised granular waste). Landfill WAC for monolithic wastes only apply to landfills

accepting hazardous wastes and those accepting stable, non-reactive hazardous

wastes. However, all producers and receivers of monolithic wastes need to be aware

of the following proposed limit values for monolithic wastes accepted at landfills for

stable, nonreactive hazardous and hazardous wastes.

a) Limit values on input wastes to treatment process generating monolithic wastes.

b) Limit values on cumulative release at 64 days from a diffusion test for the purposes

of characterising the output of the treatment plant.

c) Limit values on cumulative release at 4 days from a diffusion test for compliance

purposes.

Limit Values on Outputs from Monolithic Treatment Process

532. Quantitative limit values have been proposed for regulating the chemical

characteristics of monolithic wastes accepted into landfills for hazardous waste and

stable non-reactive hazardous waste. The same diffusion tank test is used for both

characterisation and compliance. For characterisation, the full 64 day tank test is

followed and cumulative leaching at 4 days and 64 days used to assess short and long

term leaching behaviour. As a routine compliance test, cumulative leaching over the

first 4 days is required to be below the 4-day cumulative limit values.

Table 6-29 Limit Values for Compliance Leaching Test for Monolithic Waste from


Parameter and

substances

Stable Non-Reactive hazardous waste

in non-hazardous landfill and non-

hazardous waste in same cell

Hazardous waste acceptable

at non-hazardous waste

landfills

Cumulative Limit Values (mg/m2)

For compliance

(4 day leaching)

For

characterization

(64 day leaching)

For

compliance

(4 day

leaching)

For

characterization

(64 day

leaching)

As 0.325 1.3 5 20

Ba 11.25 45 37.5 150

Cd 0.05 0.2 0.25 1

Cr 1.25 5 6.25 25

Cu 11.25 45 15 60

Hg 0.025 0.1 0.1 0.4

Mo 1.75 7 5 20


221

Ni 1.5 6 3.75 15

Pb 1.5 6 3.75 15

Sb 1.5 6 5 20

Se 0.075 0.3 0.625 2.5

Zn 0.1 0.4 1.25 5

Cl- 7.5 30 25 100

F- 15 60 50 200

SO42- 2,500 10,000 5000 20,000

Dissolved

Organic

Carbon (DOC)

Must be

determined

Must be

determined

Must be

determined

Must be

determined

pH Must be

determined

Must be

determined

Must be

determined

Must be

determined

Electrical

conductivity

(µS/cm1.m2)

Must be

determined

Must be

determined

Must be

determined

Must be

determined

533. Under the Landfill (England and Wales) (Amendment) Regulations 2005, in

order to dispose of any material at landfill there is a requirement to classify the waste

as Hazardous, Non- Hazardous or Inert. In order to comply with this requirement Waste

Acceptance Criteria (WAC) analysis must be undertaken in line with British Standard

European Norm (BS EN) 12457. WAC testing does not determine whether a waste is

hazardous or non-hazardous but for which particular type of landfill the waste is

suitable.

a) BS EN12457-1 is a single stage leaching process at a liquid: solid ratio of 2:1.

Analytical data is reported as mg/kg dry weight, calculated by using the dry ratio.

The breadth of analysis is not specified under BS EN 12457-1 can be tailored to

site-specific requirements.

b) BS EN 12457-2 is a single stage leaching process at a liquid: solid ratio of 10:1.

Analytical data is reported as mg/kg dry weight, calculated by using the dry ratio.

Similar to the National Rivers Association (NRA) 10:1 leaching method, BS EN

12457-2 does not have a specific suite of analysis and can be tailored to site-

specific requirements.

c) BS EN 12457-3 utilises a two stage leaching process at liquid: solid ratios of 2:1

and 8:1, the combined results from which are calculated to provide analytical data

reported as mg/kg dry weight at 10:1, moisture content corrected. The suite of

analysis under BS EN 12457-3 is descriptive to a minimum point, however,


222

additional analysis can be undertaken to address any site-specific requirements.

534. The UK Environment Agency’s “Waste Sampling and Testing for Disposal to Landfill” states that BS EN12457-2 should be used for all waste types, unless rapid

leaching of contaminants is expected, when BS EN12457-1 is considered appropriate.

6.3 United States


6.3.1.1 MSWI

535. According to U.S. Environmental Protection Agency, in 2014 about 258 million

tons of municipal solid waste (MSW) were generated. Over 89 million tons of MSW

were recycled and composted, equivalent to a 34.6 percent recycling rate (see Figure

6-17 and Figure 6-18). In addition, over 33 million tons of MSW were combusted with

energy recovery and 136 million tons were landfilled.

536. Most of the MSW combustion in the U.S. incorporates recovery of an energy

product (generally steam or electricity). In 2014, about 33.1 million tons (12.8 percent)

of materials were combusted for energy recovery (see Table 6-18). From 1990 to 2000,

the quantity of MSW combusted with energy recovery increased over 13 percent to

about 34 million tons. MSW combustion for energy recovery has decreased from about

34 million tons in 2000 to 33.1 million tons in 2014.

537. In the United States, the future use of incineration units for MSW management

will depend on various policies. A greenhouse gas (GHG) reduction policy might

possibly result in an increase in the construction of new incineration plants depending

on how such a policy might affect landfills, as incineration generated less GHG

emissions than land filling.


223

Figure 6-17 MSW Generation Rates, 1960 to 2014

Figure 6-18 Management of MSW in the United States, 2014

538. The energy recovery statistic includes combustion of MSW in mass burn or

refuse-derived fuel form, and combustion with energy recovery of source separated

materials in MSW (e.g., wood pallets and tire-derived fuel). There are 167 MSW

incineration units larger than 250 ton/day incineration capacity. These incineration

units are referred to as “large” incineration units and represent more than 90% of municipal solid waste incineration capacity. MSWIs have multiple incineration units on

site with 2 or 3 incineration units per plant being the most common. The 167

incineration units are located at 66 incineration plants. The average size of these

incineration units is 535 ton/day capacity and the average size of the incineration plants

is 1,355 ton/day. There are about 60 small MSWI units of less than 250 ton/day


224

capacity. Their average size is 120 ton/day incineration capacity. There are 133

incineration units of the water wall mass burn configuration and 34 incineration units

of the waterwall refuse derived fuel (RDF) configuration. The large and small MSWIs

in combination have approximately a 2,700 megawatt electric (MWe) nameplate

generation capacity and generate about 22,000 GWh electric power per year.

539. For MSWI units in the United States, the suite of controls used to control

emissions is generally the same at large and small units. The spray dryer scrubbing

system is the primary control used at MSWI units. About 97 % of the incineration units

use spray dryer based scrubbing systems. The air pollution control applications of the

167 incineration units are as follows:

Table 6-30 Air Pollution Emission Control Unit in MSWIs

Air Pollution Control Number of MSWI Units

SD/FF/ACI/SNCR 94

SD/DD/ACI 5

SD/FF/SNCR 21

SD/FF 18

SD/ESP/ACI/SNCR 15

SD/ESP/ACI 4

SD/ESP/FF/ACI 2

SD/ESP 4

DSI/FF 2

DSI/GBF 2

Where: SD spray dryer FF fabric filter ACI activated carbon injection

SNCR selective non catalytic reduction

ESP electrostatic precipitator DSI dry sorbent injection

GBF gravel bed filter

6.3.1.2 Ash Generation

540. According to U. S. EPA (2016b), the amount of ash generated ranges from

15-25 percent (by weight) and from 5-15 percent (by volume) of the MSW processed.

Generally, MSW combustion residues consist of two types of material: fly ash and slag.

Fly ash refers to the fine particles that are removed from the flue gas and includes

residues from other air pollution control devices, such as scrubbers. Fly ash typically

amounts to 10-20 percent by weight of the total ash. The rest of the MSW combustion

ash is called slag (80-90 percent by weight). The main chemical components of slag


225

are silica (sand and quartz), calcium, iron oxide, and aluminum oxide. Slag usually has

a moisture content of 22-62 percent by dry weight. The chemical composition of the

ash varies depending on the original MSW feedstock and the combustion process.



541. Basically, in order to reduce the adverse effect of FA, different treatment

techniques are being practiced. According to ISWA report (2008), these treatments are

(1) extraction and separation using water or acid, (2) chemical stabilization using

carbon dioxide/phosphoric acid (CO2/H3PO4), ferrous sulfate (FeSO4) , sodium sulfide

(Na2S) , and orthophosphate (PO43-) , (3) solidification using lime, cement, asphalt, and

gypsum, and (4) thermal treatment, such as vitrification and pyrolysis. The

technologies are not different from EU.

542. In U. S., slag and air pollution control (APC) residues are mixed together at

most MSW incineration facilities and disposed as a “combined ash”. The ash is sent to landfills. At the present time most operating facilities in the United States recover the

ferrous metal fraction present in ash, which can comprise up to 15 percent of the total

ash fraction. Only a very small fraction (less than 5 percent) of the nonferrous fraction

of the ash generated in the United States is recovered and utilized. Most of the ash is

used as a landfill cover material. There is some commercial use of ash in road paving

applications. The technologies are summarized as follows by Sun.

1) Hot Mix Asphalt

543. After screening, magnetic separation, ferrous and nonferrous metals are

removed from mixed ash or BA. Mixed ash or BA with appropriate particle size can be

mixed with other aggregates, used as a mixture of asphalt pavement. From the 1970s

to the early 1980s, the US Federal Highway Administration (FHWA) had successfully

completed at least six asphalt pavement demonstration projects using mix ash in cities

like Houston, Washington and Philadelphia. These ashes are used in the adhesive

layer, the wear layer/surface layer and the roadbed of the road. The results showed

that when used in the adhesive layer or roadbed, the best ash content was no more

than 20%; used in the wear layer/surface layer, the best ash content was not exceed

15%. Also, the demonstration project indicated that, as long as proper handling, ash

used as asphalt will not cause environmental pollution.

2) Cement and Concrete


226

544. Fly ash contains large amounts of SiO2, Al2O3 and CaO, its composition is

very similar to the composition of raw materials for cement production. Therefore, fly

ash could be a possible replacement of raw material in cement production. The high

levels of heavy metals and chloride in fly ash affect the product quality. Washing pre-

treatment of fly ash to reduce water-soluble substances like chloride before cement

curing greatly enhance the compressive strength and reduce the leaching toxicity of

the products. Based on S/S technology, fly ash can be potentially applied as a

replacement of cement or as an aggregate, but the quantities of fly ash added to the

process should be carefully controlled in order to ensure the process safety as well as

product quality. In the United States and the Netherlands, slag (or mixed ash) is used

as a partial substitute aggregate for concrete. The most common is mixing the slag,

water, cement and other aggregates to make concrete blocks by a certain percentage,

which has been commercialized in the United States. Processed after ferrous recovery

and screened to size, stabilized BA and combined ash (85% ash and 15% type II

Portland cement) used in masonry blocks and artificial reef by Waste Management

Institution of Marine Scientific Research Center in Stony Brook University in Long

Island Sound seabed. The result shows that the blocks were stronger than original

concrete blocks, and there is no ground or water pollution during six years.

3) Landfill Cover

545. Landfill sites have environmental protection facilities such as barrier layer and

leachate recovery system, the adverse effects on human health and environment

caused by heavy metal leaching from ash can be well controlled. The pretreatment

process for ash such as screening, magnetic separation and particle size distribution

is unnecessary if used as landfill cover. Therefore, in consideration of economy,

environment and technology, ash used as landfill cover material is a very good choice.

Combined ash used as landfill cover at landfill in Honolulu, Hawaii showed very well

performance.


546. In a MSWI in Westchester, New York State, After removing metal material and

cement material from slag, the slag is mixed with fly ash. The ash is sent to landfill site.

In New York State, it is required to mix slag and fly ash before landfilling. The reagent

for chemical stabilization is not used. Like this, almost all ash is disposed by landfill.

547. Beneficial use of combined ash as a landfill construction material and road

construction material are limited. Florida is a most advanced state for this recycling of


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ash. In 1998, the Florida Legislature amended certain provisions of the Florida Statues

to encourage the beneficial reuse of municipal waste-to energy ash in manners that

are protective of human health and the environment. To that end, the Florida

Department of Environmental Protection developed a document entitled "Guidance for

Preparing Municipal Waste-to-Energy Ash Beneficial Use Demonstrations" to assist

communities in developing reuse demonstrations. It was determined that nearly 3

million cubic yards of landfill space could be saved through beneficial reuse of the ash.

An initial analytical screening was performed to test the leaching potential of the eight

RCRA metals and compare to applicable groundwater and surface water standards.

Overall results were favorable, with some indication that lead could pose potential

concern. Geotechnical index testing (grain size, moisture content, and organic content)

was performed to determine if ash has similar physical properties to the sand that is

currently used on-site. Results indicated that the ash has similar physical properties to

the sandy material. Combined ash was used in this test.

548. Recently, in Florida, some tests to evaluate the use of MSWI ash as road

construction materials were conducted. The MSWI slag was also used to replace fine

aggregate in hot-mix asphalt (HMA). Varying proportions of slag and fine aggregate

were tried in an effort to determine the optimum ratio of slag to fine aggregate, as

determined by performance tests such as the Marshall stability test and the moisture

susceptibility test. For the optimum replacement ratio of slag, the optimum binder

content required was evaluated. Recently, Florida state has approved the use of MSWI

slag as road construction materials.



549. The Resource Conservation and Recovery Act (RCRA) is the nation’s primary law governing the disposal of solid and hazardous waste in Untied States. The

hazardous waste management, under Subtitles C of RCRA, established a system for

controlling hazardous waste from “cradle to grave”. The RCRA regulations governing

hazardous waste identification, classification, generation, management and disposal

are set forth in different parts of title 40 of the Code of Federal Regulations (CFR).

550. According to RCRA, MSWI ashes are subject to testing by the Toxicity

Characteristic Leaching Procedure (TCLP) prior to disposal. Residues which pass

TCLP are subject to management as a non-hazardous solid waste, while residues

which fail TCLP are subject to management as hazardous waste or special waste,


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depending on state requirements. In practice, operations at most MSWI facilities have

been adjusted so that failure to pass TCLP is a rare event. Required testing frequency

varies considerable from state to state, typically ranging from testing of weekly to

quarterly composite samples. The most frequent disposal options practiced for

combined ash are disposal in a landfill which receives only MSWI residues (termed a

“monofill”), disposal in a segregated cell within a MSW landfill which only receives MSWI residues, or disposal on top of previously landfilled MSW. Several jurisdictions

are evaluating the use of MSWI residues as daily cover for conventional MSW landfills.

551. Utilization of MSWI residues has been sought in jurisdictions which have high

costs associated with disposal of MSWI residues, limited disposal capacity which is

constrained by the difficulty associated with siting new landfills, or limited reserves of

natural aggregate. The conditions are most prevalent in areas with high population

densities. While several utilization options have been considered, the most promising

utilization scenario is use of slag as an aggregate substitute in road construction

applications. FHWA provides “User Guidelines for Waste and Byproduct Materials in

Pavement Construction”.


552. Firstly, solid waste management in US is described in 6901 of title 42 of the

CF as follows.

553. While the collection and disposal of solid wastes should continue to be

primarily the function of State, regional, and local agencies, the problems of waste

disposal as set forth above have become a matter national in scope and in concern

and necessitate Federal action through financial and technical assistance and

leadership in the development, demonstration, and application of new and improved

methods and processes to reduce the amount of waste and unsalvageable materials

and to provide for proper and economical solid waste disposal practices. Therefore,

basically, State, regional, and local agencies have to manage municipal solid waste

under subtitle D in RCRA.

554. The RCRA Subtitles C Section 3001 requires EPA to “develop and promulgate criteria for identifying the characteristics of hazardous waste, and for listing hazardous

waste, which should be subject to the provisions of this subtitle, taking into account

toxicity, persistence, and degradability in nature, potential for accumulation in tissue,

and other related factors such as flammability, corrosiveness, and other hazardous

characteristics”. It is recognized to de legate authority to State from EPA for


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Formulation and implementation of concrete program. Because some states has more

strict programs, EPA can approve the program and the States can implement the

program Also, EPA can order the State, regional, and local agencies to take corrective

action about pollution from hazardous waste disposal under RCRA subtitle C.


555. By the TCLP test Method 1311, if any of the contaminant level from an extract

of a representative solid waste is at or exceeds the regulatory level, the solid waste is

considered to exhibit toxicity characteristics, and is classified as a hazardous waste.

Table6-31 shows maximum concentration of contaminants for the toxicity

characteristic.

Table 6-31 Maximum Concentration of Contaminants for the Toxicity Characteristic


230

556. The approach for the derivation of the TCLP regulatory level takes into

account three key determinations: acceptable level at the groundwater consumption

point based on risk, the dilution/attenuation factor between the disposal unit and the

receptor, and the leachate concentration from the waste that would be permitted. In

addition, explicit determination of allowed concentration from risks of exposure to the

leached constituents is needed. Particularly, the risks are based on risk-specific doses

for carcinogenic compounds that result in an incidence of cancer equal to or less than

10-5, reference doses for non-carcinogenic constituents based on an estimate of the

daily dose of a substance that will result in no adverse effect even after a lifetime of

such exposure, and the proposed maximum contaminant levels in drinking water.

6.3.3.4 Implementation Procedures and Safeguarding Measures

557. Tracking and licensing are two management program of hazardous waste in

United States. Each enterprise related to hazardous waste (large quantity generators

and treatment enterprise) are required to get the EPA identification number from the

Administrator, and RCRA requires a permit for the “treatment,” “storage,” and “disposal” of any “hazardous waste” as identified or listed in 40 CFR part 261. In order to track


231

the generation and transfer of hazardous waste, EPA requires large quantity

generators and small quantity generators to prepare a manifest and keep a copy of

each manifest. According to 40CFR, the copy of each manifest must keep for three

years.


558. US Federal Highway Administration (FHWA) made the User Guidelines for

Waste and Byproduct Materials in Pavement Construction to encourage appropriate

widespread use of secondary materials (i.e., waste and byproduct materials) and

associated technologies in the construction and rehabilitation of highway infrastructure.

In municipal solid waste combustor ash, material description, granular base and

Asphalt Concrete – Aggregate are recorded (FHWA-RD-97-148).

6.4 Summary

559. In Japan, because of the shortage of appropriate land for final disposal sites,

recycling methods to avoid landfilling have been conducted In the meantime, concerns

began to arouse over pollution caused by dioxins in treatment facilities due to their high

concentrations in fly ash, which led to enhancing regulations to target at reduction of

dioxins in exhaust gas and generated ash of waste incineration plants. In this

situation, bottom and fly ash melting facility and gasification melting facility were

developed and promoted, but they have not been popular mainly because of their low

cost effectiveness. Though they did have effect on reducing dioxins levels, the

treatment costs were higher than that of stoker furnace. As they also consume a lot of

amount of energy and generate much CO2, they are currently under reassessment.

There are private electric furnace businesses that have reductive melting technology

with high expertise and engaged in waste recycling business. These are promising.

Recycling ash into cement material is also promising Even though manufacturing eco-

cement requires a dedicated plant construction newly, it can be a viable business in

urban areas. the cost of them is considered cheaper than that of local gabernment

self treatment owning melting plant. We should take note that Japanese technologies

for ash recycling are almost all co-treatment of bottom ash and fly ash. High

temperature technologies ex. melting and sintering are not usable for fly ash only .

560. In EU, fly ash management differs among countries. Especially, in The

Netherland, In keeping with the practice of recovering reusable resources from wastes,

fly ash can be reused in construction applications such as asphalt filler. For solid waste


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to be reused as construction material, the solid waste must meet the criteria as

stipulated in the Dutch Building Materials Decree. This policy has led, to date, to a

recovery rate of fly ash of around 50%. On the other hand, in Germany, the fly ash is

strictly regulated and basically stored in waste salt mine. In other countries, cement

solidification and/or chemical stabilization is a major technology to meet the EU or each

country’s regulation.

561. In US, fly ash and bottom ash are mixed together at most MSW incineration

facilities and disposed as a combined ash. Most of the ash is used as a landfill cover

material. There is some commercial use of as in road paving applications.

562. Finally, fly ash treatment or recycling technologies are summarized in Table

6-32. Currently, chemical stabilization and/or stabilization treatment with cement is

popularly used for MSWI fly ash to prevent heavy metal release from final disposal site

in all over the world. High temperature process such as melting and eco cement

process are used in Japan but not popular in the world. Although acid extraction and

neutralization are not so popular, if specific industries can use MSWI fly ash for this

purpose, these technologies are relatively good. In US and Netherland, MSWI fly ash

is used as asphalt filler or road paving applications. In this case, the management of

the final products from MSWI fly ash are necessary because the product is directly

used in the environment.


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Table 6-32 Disposal or Reuse Technology of Fly Ash

Melting

(Vitrification)

Cement Solidification, Application

Chemical Stabilization With Chelate or Other

Reagent

Acid Extraction,

Salt Recovery

Calcination (Sintering, Eco-Cement, Etc.)

Neutralization Asphalt Landfill

Cover of Filter

Advantage

Candecompose Dioxin and Fix Heavy Metal in

Slag

Cheap Easy Application

Can Recover Metal from

Waste

Can Decompose Dioxin And

Recover Heavy Metal

Substitute of Alkaline Reagent

Substitute of Sand/

Filter Material

Substitute of Sand/

Filter Material

Disadvantage

Expensive, Energy

Consuming, High

Maintanance

Volume

Presence of Excess Chemicals

in Leachate

Need Waste Water

Process and Low Grade

Expensive, Energy

Consuming

Limited Application

Limited Application

Limited Application

for Dioxin Decompose No No No Decompose No No No

for Heavy Metal

Stable in Slag, But Secondary Ash Generation

Not Effective for Some Elements

Can Choose Suitable

Chemicals

Can Recover Secondary Ash

Generation No

Effective for Some Elements

No

Technical Difficulty

Level Moderate Easy Easy Moderate Moderate Moderate Easy Easy

Cost High Cheap Moderate Moderate High Cheap Moderate Cheap

Disposal Amount in

Landfill Small Large Moderate Small Small Small No No

Long Term High Low Moderate Moderate High Low Moderate Low


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Stability of Final

Residual Resource Recovery

Yes* No No Yes Yes No No No

Use as Construction

or Raw Materials

Slag: OK Difficult Difficult Difficult Sintering

Product Or Brick: OK

No Yes Yes

China Ⅹ O O Ⅹ Δ Ⅹ Ⅹ Δ

Japan Δ* O O Δ O Δ Ⅹ Ⅹ

US Ⅹ Δ Δ Ⅹ Ⅹ Ⅹ O O

EU Δ O O O Ⅹ Δ Δ Δ

comment

Yes* In some cases in Japan, not only slag but also fly ash from melting process are also recovered and used at private sectors

(slag is mainly used as construction material and Zinc etc. in melting fly ash is recovered from non-ferrous industries). △* In case of Japan, melting process means co-melting bottom ash and fly ash at present. Melting process for only fly ash is no

longer used due to many troubles and high maintenance cost. Reference

TA-8963 PRC Final Report Chapter VII

235

CHAPTER7 CHALLENGES FOR SUSTAINABLE

MANAGEMENT OF MSWI FLY ASH IN THE PRC

7.1 Comparative Analysis of Gap between International and Domestic Technologies

563. China's research on the sustainable disposal technology of the incineration fly

ash and its standard is relatively late. The relevant theoretical system, target system,

certification system, supervision system and corresponding standard system are still

in the initial establishment, thus the infrastructure capability is still weak. Developed

countries, represented by Germany, the United States and Japan, have begun to study

the sustainable disposal mechanism of incineration fly ash very early and have

accumulated a lot of practical experience. Table 7-1 shows the disposal situation of

incineration fly ash in developed countries. It can be seen from the table, fly ash

treatment methods in developed countries are diverse with a high degree of harmless

feature; the fly ash after the innocent treatment is mostly sent to the landfill site;

resource utilization concentrates more in the roadbed, embankment and construction

aggregate, but approach for large-scale resource utilization is still in the middle of

research and exploration.

Table 7-1 Disposal Situation of Incineration Fly Ash in Developed Countries

Country Main Disposal Method Resource Utilization

Approach

The USA Fly ash is sent to the single landfill after mixture

with slag.

Daily cover and

closure final cover of

landfill site, asphalt

aggregate, concrete

aggregate etc.

Canada Fly ash is sent to landfill of hazardous waste. ——

Holland

Fly ash is stored in dedicated bags in a controlled

landfill, regardless of resource utilization. Waste

recycling is only for research.

Roadbed filler ,

embankment filler,

concrete aggregate

and asphalt

aggregate

Denmark Fly ash is exported or stored in dedicated bags. Parking lot, roadbed

material

Germany Fly ash is stored in underground mines such as

rock salt mines.

Roadbed and sound

barrier

France Fly ash is solidified with hydraulic binder and

stored in specified holes of landfill. Public works

Switzerland

One part of bottom and fly ash are sent for landfill

after the leach with metal, the other part is

transported to Germany.

Metal recycling


236

Country Main Disposal Method Resource Utilization

Approach

Sweden Fly ash is sent to safe landfill site after treatment.

Road pavement

within the limits, so

the degree of

resource utilization is

limited.

Portuguese Fly ash is solidified with hydraulic binder and

stored in specified landfill sites. ——

UK Fly ash is sent to the specified landfill sites after

solidification. ——

Japan

With sediments used as road construction

materials, fly ash is solidified (melting, cement,

chemical agent, separation and leach, etc.) for

stabilization before treatment, and sent to landfill

site after cement solidification and stabilization.

Filler, embankment

filler, concrete

aggregate and

asphalt aggregate

7.1.1 Japan

564. In Japan, the early incineration sediments were buried together with urban

waste without being processed in compliance with relevant standards. But because of

its secondary pollution, in July 1992 the Japanese government announced the

amendment of Law of Waste Treatment, which, referring to the provisions of Subtitle

C in Resource Conservation and Recovery Act (RCRA) of the US, divided the waste

into general waste, general waste under special management, industrial waste and

industrial waste under special management, and listed the waste with explosion,

toxicity, infection and other harms to human’s health and living environment into the

list of special management. The amendment provided fly ash was a general waste

under special management and that the fly ash and the slag should be collected and

stored separately. The Waste Disposal and Public Cleansing Law clearly stipulated

that fly ash must pass one of the following four treatment methods: melting and

solidification, cement solidification, chemical stabilization and acidic leaching before

entering the landfill site.

565. Because the content of plastic materials in MSW is very high, so the content

of chlorides, especially alkali chloride, is very high in the incineration fly ash, thus the

strength and immersion persistence of the solidified body are poor when the fly ash is

solidified by cement or lime. Blocking on the heavy metals is only due to its strong

alkaline effect. In addition, the long-term fixation effect of heavy metals is poor and

dioxins are difficult to be eliminated or stabilized. Therefore, the Japanese related

research focused on high-temperature treatment, especially the melting vitrification.

From the 1980s onwards, the government started to lead the development program of

melting technology, now Japan has become one of the most extensive countries in the

application of melting method to treat incineration fly ash. Although the high-

temperature treatment is high-cost, because of its high degree of stability and even

quality, and harmless, stable and resource-based goals, it is drawing more and more


237

attention.

566. The main process route is that under certain conditions, the fly ash is mixed

with the secondary raw materials (coal, bentonite, etc.), and the mixture is pulverized,

made into particles and then dried to enter the cement kiln for calcination. The calcined

material is a lightweight aggregate and can be used as a building ceramsite. One part

of the exhaust gas and secondary fly ash produced during the calcination process can

be returned to the cement kiln for re-burning and the other part will be sent into the

dust collection device. And through bag collector and wet treatment, Zinc, Lead,

Cadmium and other heavy metals can be recovered. Finally, the gas is washed through

the scrubber and adsorbed and discharged by the activated charcoal.

567. At the same time, the Japanese industrial specifications JIS A5031 and JIS

A5032 also made the provisions on quality, test methods, inspection, labeling,

reporting and application range of concrete aggregates and roadbed materials

prepared by municipal solid waste and its incineration sediments.

7.1.2 USA

568. In the USA, since the federal government does not disclose the laws and

regulations on the definition of incineration sediments, each state set their own relevant

regulatory standards, so that there are different requirements of storage, collection and

disposal across the USA. In storage and collection, some states require slag and fly

ash of incineration sediments to be separated for storage and mixture of them is

forbidden, but for most of the states, this requirement is not mandatory. In the middle

treatment, for most of the states, the incineration sediments are transported to the

landfill without treatment, only some states treat the sediments with the cement

solidification, chemical stabilization and other intermediate treatments before the final

landfill. In the final disposal, the requirements of the states also vary with each other;

some states allow the mixture landfill of incineration sediments and other waste while

some states require incineration sediments must be separately buried; and for landfill

facilities, some states require only a single natural or synthetic impermeable layers

while some states require a two-layer or three-layer impermeable barrier.

569. In addition, since 1979, after passing the RCRA, there was a dispute on the

definition of the incineration sediments between the US Environmental Protection

Department and operators of the resource recycling plants. In May 1994, the United

States Supreme Court defined that incinerated ash was a hazardous waste suitable

for use of Subtitle C of RCRA and that TCLP dissolution tests had to be carried out. If

the results didn’t comply with the relevant standards, it would be considered as hazardous waste subject to the provisions of Subtitle C for treatment and disposal. In

January 1995 The United States Environmental Protection Agency stipulated that

before incineration sediments were transported away from the waste recycling plant,

the dissolution test should be carried out to determine whether it was hazardous waste.

The US Environmental Protection Agency did not enforce that fly ash and slag must


238

be collected separately, but in order to avoid that fly ash with high heavy metal content

was identified as hazardous waste, causing additional treatment and disposal costs,

operators of resource recycling plant often collected and stored fly ash mixed with the

slag with low content of heavy metals, and diluted the mixture to reduce the content of

heavy metals in incineration sediments, so as to reach the standards of dissolution test.

7.1.3 EU

570. In the late 1980s and early 1990s, Europe built a number of melting facilities

for simultaneous treatment of fly ash and slag, but none of these facilities were

currently in operation. This is mainly due to the high energy consumption of the melting

method, one ton of sediments with energy consumption up to 1 MWh (incineration

sediments of each ton cost about 30 to 60 US dollars).

571. Germany defines fly ash as hazardous waste and regulates that the fly ash

shall not be mixed with the slag and be disposed of by the landfill method. German law

stipulates that if the economy permits, all sediments must be recovered. For the slag

treatment, as with other European countries, about 60% of the slag is used for road

pavement and other similar use, but before its resource utilization, it needs to be stored

for three months before use, and the burning reduction shall be below 5% and moisture

content below 2%. Fly ash is mainly disposed of by means of deep mine storage. Deep

mine storage refers to placing the fly ash in the container that will be stored for a long

term storage in the deep mine space formed after mining and isolated from the

biosphere, thus the long-term geological stability is required, and there should be no

groundwater and with a multi-layer impermeable barrier, and the depth should be over

400 meters beneath the ground surface, the preferred mine is a rock salt mine; the

deep mine storage is considered to be the safest disposal of hazardous solid waste

with high toxicity. The technology is mainly popular in Germany, a country with the

extremely strict environmental requirements. In 2002, the German government issued

a special Waste Underground Landfill Regulation to regulate and promote the

development and application of the disposal technology. In 2005, Germany's

production capacity of incineration fly ash was about 350,000 tons, of which about 57%

was recycled, 30,000 tons was stored in deep waste mine, the rest was put into the

innocent treatment, of which part was processed with solidification.

572. Swiss watch has been a world leader in the industry; in recent years, due to

a substantial increase in export and continuously rising price of international metals of

raw materials, the metal demand and cost in Switzerland followed with a sharp rise,

which, coupled with the original shortage of domestic mineral resources, makes that

the metal recycling in the sediments after waste incineration has been a concern. By

2013, Switzerland has 28 domestic stove-based incineration facilities, processing 3.55

million tons of waste per year and producing about 80 million tons of slag and 80,000

tons of fly ash. 97% of the slag is recovered with Fe, Cu, Al and precious metals after

electromagnetic separation and melting, and treated residues is sent for landfill; the

above treatment has become a usual practice in the country. About 40% of the fly ash


239

after acidic treating will be recycled with electrochemical technology for recovery of

heavy metals (Cu, Pb, Zn and Cd, etc.), which, however, has not yet been fully a usual

practice; and the main technical processes in it are: washing of fly ash (FLUWA,

Flugaschenheasche) and the latest fly ash recycling (FLUREC, Flugas-chenrecycling).

Among them, FLUWA has been adopted by 13 incineration enterprises, with a

recovery rate of high-purity zinc up to 1 800t / year.

573. Denmark is more lenient to incineration sediments in the relevant laws and

regulations; if the incineration sediments are in compliance with the relevant regulatory

requirements, such as heavy metal content: Pb <300mg / kg, Cd <10mg / kg, Hg

<0.5mg / kg, etc., it can be recycled as roadbed material, aggregate, casing, etc., if not

meet the requirements, it will be disposed of with coastal management and other

means under the principle of not polluting the underground water sources. Because

heavy metal content of fly ash is high, so when the recycle of ash sediments are taken

into account, the fly ash and slag shall be separately collected. In the relevant

application engineering, the slag is a good substitute for gravel; it can reduce the

burden of landfill and processing costs of landfill. Fly ash is classified as a hazardous

waste; flue gas collected in dry or semi-dry purification system is classified as

dangerous waste and is typically packed in a polyethylene bag and transported to a

dedicated landfill for separate landfill; these landfill sites contain leachate collection

systems and linings and impermeable layers; and the fly ash from wet scrubbers is

usually either buried separately or mixed with flue dust. However, the above-mentioned

methods are temporary disposal measures before the viable methods are found. After

treatment, the fly ash can be buried in a landfill to build a new habitat.

7.1.4 China

574. At present, China's main technologies of treatment and disposal of waste

incineration sediments and resource utilization include cement solidification, chemical

stabilization, building materials utilization technology (co-processing technology in

cement kiln), melting and solidification (sintered ceramsite technology) and so on. As

China's research on disposal of waste incineration fly ash and technology of resource

utilization was carried out lately, so now there is no applicable and fixed processing

technology for the treatment and disposal of the fly ash with the high chlorine content.

Some commonly used processing technologies are also often with technical

bottlenecks, for example, cement solidification is low in strength of solidified body of

cement and high in leaching rate of heavy metals after cement solidification, and the

consumption of cement is high under the same conditions; chemical stabilization has

the problem of high-dosage adding of the same type of chemical agents in production

process of organic chelation under the same effect; melting and solidification is only in

the experimental stage, far from the stage of application.


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7.2 Technical Challenge

575. Fly ash is the purification product of incineration flue gas; because the waste

compositions are various, and the incineration processes and flue gas purification

processes for kinds of wastes are also different, so it results that compositions of the

fly ash vary greatly, which, coupled with huge production, complex characteristics,

interference and high content of volatile elements, makes its subsequent utilization is

difficult to predict. On the Basis of the nature and treatment characteristics of fly ash

in China's MSW incineration, the treatment and utilization of fly ash must be taken into

account in terms of resource utilization and environmental impact. It is necessary not

only to consider the feasibility of resource utilization of fly ash to find the best balance

between economic cost and environment protection, but also to have the

environmental characteristics of processed products of fly ash reach the limited

standards.

576. The risk of fly ash is mainly from heavy metals and dioxins, and the treatment

of fly ash is to minimize it. Risk will be reduced in the follow-up treatment when dioxins

are removed by degradation. Since heavy metals can’t be degraded, it is difficult to achieve the source abatement; solidification or extraction for recovery of heavy metals

can help to achieve the goal of controlling environmental risks. With good stability,

melting and solidification can firmly confine the heavy metals in the molten vitreous

body, so as to effectively control the leaching of heavy metals. But the implementation

of melting and solidification is difficult, and in the treatment the total amount of heavy

metals can’t be reduced, so the effect of discharge reduction is not significant. The recovery technology of heavy metals can radically realize the innocent treatment of the

fly ash, not only transforming waste into resources, reducing environmental pollution,

but also converting fly ash from hazardous waste into inert solid waste.

577. The existing recovery technologies of heavy metals mainly include

conventional hydrometallurgical method and electrochemical method. Acidic leaching

can highly leach out heavy metals, but since a large amount of chloride and sulphate

is also leached, the chemical properties of the system is very complex, selective

separation for a variety of heavy metals can’t be easily achieved; alkali leaching can selectively leach out amphoteric metals of Pb and Zn, but with a low leaching rate,

resulting in that a large amount of heavy metals still remain in the residue, the product

still needs to be solidified or stabilized as a hazardous waste; the method of ammonia

complex leaches Pb, Cu and Zn in the form of complex simultaneously, avoiding

interference of ions of Fe, Al, Mg, Ca and other metals, but complexes of Cd, Cr, Mn,

Mo, V and other heavy metals will be leached out at the same time, so it is difficult to

separate them selectively; electrochemical technology theoretically can control the

reduction potential of ions of the metals, realizing selective separation of Pb, Cu and

Zn, but because of the existence of cross-regions between the reduction potential of

other metal ions and the ions of target metal, a mixture of various metals is often

obtained on the electrodes. It can be seen that a single extraction method can’t


241

effectively separate and recover heavy metals, it is necessary to adopt a combined

process to selectively extract heavy metals. How to achieve the recovery of heavy

metals at the same time of efficiently processing the fly ash is a new opportunity and

a challenge for the development of China's ash treatment and disposal technology.

7.2.1 Cement Solidification

578. For cement solidification, the main constraints in the practical application are

mainly heavy metal control and poor stability of cement solidified body. The effect of

heavy metal control is directly related to the final effect of cement solidification. The

failure of heavy metal control will directly lead to the failure and collapse of treatment

process of hazardous waste. Therefore, how to further improve the stability and

leaching safety of heavy metals in cement solidified body is worthy of further research.

In addition, the research on how to effectively control and eliminate the decline of

treatment effect on incineration fly ash from MSW caused by the poor stability of

cement solidified body still needs to be further promoted and improved.

7.2.2 Chemical Stabilization

579. The main technical challenges for chemical stabilization treating incineration

fly ash from MSW include the following two aspects: on the one hand, the stability

effect on the complex state of heavy metals is still pending further study. However,

when the PH is strongly acidic and alkaline, the rise of content of the heavy metal ions

is significant. How to further improve the environmental tolerance and chemical stability

of heavy metal complexes will be an important challenge for the treatment of chemical

stabilization. On the other hand, the price of chemical agents, especially organic

chemicals, is relatively high, which are mainly determined by the complexity of the

process and high cost of raw materials, and in China, due to the late launching

compared to overseas, the above problem is more prominent; under the same

processing capacity and treatment effect, the high expense of solidification agents has

become an important obstacle for the practice of chemical stabilization.

7.2.3 High Temperature Heat Treatment and Solidification Technology

580. High temperature heat treatment and solidification technology includes

cement kiln co-disposal, high temperature sintering ceramsite and high-temperature

melting glass technology. At present, the high-temperature heating treatment and

solidification technology requires large energy consumption, which, together with the

follow-up strict flue gas treatment for Pb, Cd, Zn and other volatile heavy metals,

results in high cost of treatment; at present, how to effectively control the volatile heavy

metals and develop the post-treatment process for the flue gas has become an urgent

problem to improve the melting and solidification technology. In addition, melting and

solidification requires a large amount of material to be heated above the melting point,

which requires a considerable amount of energy and expense, whether the electricity

or other fuels is or are consumed. Generally, the melting process for fly ash requires a


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complex processing system, so development of high-temperature melting system and

manufacturing of the corresponding ancillary equipment has also been confronted with

considerable technical difficulties and challenges.

7.2.4 Safe Landfill Disposal

581. Safe landfill disposal refers to a way that the incineration fly ash form MSW is

sent into the safe landfill after an immediately simple treatment in the field, which is

currently one of the safest and most reliable treatment means for the incineration fly

ash. But the costs of construction and operation of the safe landfill remain so high that

waste incineration plant is difficult to bear in present practical practice; in addition, the

method also can’t help to achieve the purpose of volume reduction and resource utilization, so in the future there will be a gradual decline in application of this method.

7.3 Policies and Regulations Challenge

7.3.1 Problems in the Solid Waste Law

582. The construction of solid waste management system of China began in

1995,when the government promulgated and implemented the "People's Republic of

China Solid Waste Pollution Prevention Law." So far, this law has undergone a revision

and three amendments. As the Solid Waste Management continues to deepen, the

Solid Waste Law shows that it can not meet the actual needs. For MSWI fly ash, there

are several main problems.

1) Unclear Management Properties of MSWI Fly Ash

583. The Solid Waste Law clearly defines that "domestic waste refers to solid waste

generated in daily life or activities that provide services for daily life and solid wastes

that are required by laws and administrative regulations to be treated as domestic

waste." Therefore, according to this definition, as MSWI fly ash from domestic waste

disposal, it should also belong to the category of "domestic waste." At the same time,

the Solid Waste Law stipulates that "the administrative department of environmental

sanitation of the local people's government at or above the county level shall organize

the cleaning, collection, transportation and disposal of municipal solid waste."

According to these regulations, the treatment and disposal of municipal solid waste

incineration fly ash should be organized and implemented by environmental

sanitation department.

584. However, whether in working practice or in the specific provisions of the Solid

Waste Law, "domestic waste" managed by environmental sanitation authorities mainly

refers to domestic solid waste generated by households and similar types of office

waste, commercial waste , street sweeping waste and so on. Other wastes including

incineration fly ash (such as e-waste, food waste, water-treatment sludge, etc.) are not

legally specified as "domestic waste". Therefore, in the specific operation process, the

responsible units for the disposal of fly ash are often unclear. In many places, the


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municipal solid waste incineration plant takes the responsibility and is managed

according to the management concept of "industrial solid waste." In some places, the

department in charge of environmental protection is responsible , often witching the

phenomenon. The main body of management responsibility is unclear, which has

become one of the major obstacles in the reasonable disposal of fly ash.

2) Unclear Main Body Responsible for the Disposal of MSWI Fly Ash

585. The Solid Waste Law stipulates that "the state shall implement the principle

of responsible polluters according to law for the prevention and co ntrol of

environmental pollution by solid wastes" and "the producers, sellers, importers and

users of the products shall bear the responsibility of prevention and control of pollution

according to law" . According to these regulations, it is not possible to judge the main

body responsible for the harmless management of incineration fly ash. According to

the internationally accepted "producer responsibility system", MSWI fly ash disposal

should pay for by the producer of domestic waste. However, China did not establish

this system, so the cost of incineration fly ash treatment and disposal has become an

impossible step.

3) Not Established Classification Management System for Hazardous Wastes

586. As a hazardous waste, fly ash management process requires the

implementation of the various hazardous waste management systems, including

hazardous waste management plan system, hazardous waste transfer system,

hazardous waste operating permit system. However, all these systems are designed

for industrial hazardous wastes. As mentioned above, MSWI fly ash generated in the

processing of domestic waste, which should belong to domestic waste, Its

responsibility for the harmless disposal should be borne by the producers of domestic

waste, generally by the local government to exercise this responsibility, that is

responsible for the environmental sanitation department. As a result, implementers

and supervisors of hazardous waste management systems for incineration fly ash

became the two government-owned units. From this it can be seen that the absence

of management systems for hazardous wastes in domestic wastes has caused this

irrational phenomenon.

587. MEP is aware of this and MSW fly ash in the "Hazardous Waste Exemption

Management Inventory" was promulgated in June 2016 to specify that if incineration

fly ash is disposed of in landfills or cement kilns for collaborative disposal. both

processes "do not follow hazardous waste management", which shows that living

landfills or cement kilns do not need to apply for a hazardous waste permit. To some

extent, this remedy this flaw.

4) No Clear Technology Route for Solid Waste Management

588. The Solid Waste Law stipulates the basic principle of solid waste management,

that is, "the State shall implement the principle of reducing generation and harm of


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solid waste, making full and rational use of solid waste and decontaminating solid

waste for prevention and control of environmental pollution caused by solid waste to

promote cleaner production and the development of circular economy. "This is the so-

called" three principles "(ie, reduction, recycling, decontamination).

589. First, this principle does not give priority to the various management

techniques. At present, the principle of prioritization of "avoid or reduce, material

regeneration, heat regeneration and proper disposal" is widely adopted in the world.

However, this principle is not adopted by China's Solid Waste Law. In the absence of

a prioritized choice of technology, different regions of the country choose different

technologies to emphasize the importance of different technologies when choosing to

dispose of fly ash. There are large differences that hinder the orderly development of

incineration fly ash management.

590. Second, this principle only emphasizes "harmless disposal" without

mentioning "sound management of the whole process" and does not provide sound

management principles for the regeneration process of incineration fly ash resources.

Due to the lack of the principle of "sound management of the entire process", or the

disorderly development of regenerative technologies for incineration fly ash, or the

over-emphasis of "harmless disposal", the development of renewable technologies will

be blocked.

7.3.2 Unsound Standards, Norms

591. At present, the key factor restricting the harmless management of fly ash is

the imperfection of technical standards and technical specifications. The implementers,

organizers and supervisors of incineration fly ash disposal often fail to unify opinions

when they choose to dispose of incineration fly ash because of the lack of technical

documents such as corresponding standards or specifications, thus putting the

innocuous management of incineration fly ash at an impasse. Technical researchers

often because of the lack of the necessary evaluation criteria can not promote the

application in the development of incineration fly ash treatment and disposal

technologies and resource regeneration technology. Therefore, it is urgent to establish

a perfect and flexible standard system of pollution control technology for the

characteristics of incineration fly ash.

592. As mentioned before, the main disposal methods for incineration fly ash at

present are landfills (including hazardous waste landfills and domestic waste landfills),

while the main means are resource regeneration for the production of building

materials (including cement and concrete aggregates , Concrete, roadbed materials,

bricks and building materials, etc.). Therefore, the technical standards or technical

specifications for incineration fly ash pollution control should also be formulated for

these technologies, and should be able to make timely adjustments and revisions

based on technological developments and actual needs.


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593. So far, the pollution control standards and technical specifications related to

incineration fly ash disposal and resource regeneration mainly include:

❖ “standard for pollution control on the security landfill site for hazardous wastes

(GB18598 - 2001)"

❖ "Standard for Pollution Control on the Landfill Site of Municipal Solid Waste

(GB16889 -2008)"

❖ "Standard for pollution control on co-processing of solid wastes in Cement kiln

(GB30485 - 2013)"

❖ "Environmental protection technical specification for co-processing of Solid wastes

in cement kiln (HJ662-2013)"

❖ "Standard for Pollution Control on Co-processing of Solid Waste in Cement Kiln

(GB30760-2014)"

594. From this it can be seen that landfill of incineration fly ash and co-processing

in cement kilns (synergistic regeneration) have no technical barriers to management.

At the same time, the "Hazardous Waste Exemption Management Inventory"

promulgated by MEP in June 2016 also exempts landfill of incineration fly ash in

domestic waste landfill and co-processing in cement kiln, and therefore, there is no

obstacle on permit management fly ash landfill disposal and cement kiln co-disposal.

595. However, due to the widespread occurrence of incineration fly ash, the

extremely uneven degree of economic and social development in various regions, the

demand for incineration fly ash treatment technology is also extremely extensive.

Therefore, the existing pollution control technical standards and technical norms can

not meet the different needs of various regions, but also need to supplement the

existing incineration fly ash pollution control technical standards or technical

specifications. At present, there are two main technical standards or technical

specifications that need to be formulated for incineration fly ash.

(1) Pollution Control Technical Specifications of Incineration Fly Ash Packaging,

Transport And Storage

596. According to the Solid Waste Law, "Transport of hazardous wastes must take

measures to prevent environmental pollution and comply with the state's regulations

on the transport of dangerous goods." Meanwhile, the transport units that require

hazardous wastes are required to obtain the qualification for the transport of dangerous

goods. However, due to the lack of special facilities and qualifications for the transport

of dangerous goods for the characteristics of incineration fly ash, and the harmful

characteristics of incineration fly ash do not match those of dangerous goods, the

technical and management of incineration fly ash has great difficulties. The solution to

this problem could be to exempt countries from applying for hazardous waste


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incineration fly ash transportation, provided that pollution control specifications for

packaging, transporting and storing incinerated fly ash should be established as a

prerequisite for exemption.

(2) Pollution Control Standards by Producing Building Materials with Fly Ash

597. At present, the Ministry of Environmental Protection is formulating the General

Standard for Identification of Solid Waste. In the standard draft for approval there are

the following provisions:

"The use of solid waste as a substitute for the production of products that meet the

following conditions at the same time, not as a solid waste management, in accordance

with the corresponding product management:

a) In line with national, local development or industry prevalence product quality

standards of alternative raw materials;

b) Meet the relevant national standards for pollution control or technical

specifications, including the production of harmful substances in the production

process to the environment and the content of harmful substances in the product

content standards;

598. In the absence of national pollution control standards or technical

specifications, the content of harmful components contained in the product is not

higher than the content of harmful components in the products produced using the

replaced raw materials, and the harmful substances discharged into the environment

during the production of the product concentration is not higher than the concentration

of harmful substances released into the environment during the production of products

using the replaced raw materials.

c) A stable and reasonable market demand.

599. This standard has been approved by the MEP's executive meeting and will be

released soon.

600. According to this standard, the key management requirement for the use of

incineration fly ash to produce building materials is to comply with pollution control

standards or specifications for incineration fly ash production building materials. At

present, the relevant content of the existing Standard for Pollution Control on Co-

processing of Solid Wastes in Cement Kiln (GB30485 - 2013)", Environmental

Protection Technical Specification for Co-processing of Solid Wastes in Cement Kiln

(HJ662-2013)" and "Standard for Pollution Control on Co-processing of Solid Waste in

Cement Kiln (GB30760-2014)" can be used for incineration fly ash production of

cement, that is, the use of incineration fly ash production of cement, as long as the

above three criteria to meet the technical legality requirements.


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601. However, if building materials other than cement are produced using

incineration fly ash, there is no documented pollution control standard or specification.

Failure to address this issue requires the development of pollution control

specifications for incinerating fly ash production building materials.

7.4 Summary

602. Internationally, the main disposal of fly ash is landfill, but with the maturity of

application, a variety of technologies are flourishing, such as resource utilization or

heavy metal recycling in Japan, Switzerland and other countries, underground salt

storage technology in German and so on.

603. China's technological research and development of fly ash treatment and

disposal started relatively late, so first it is necessary to sum up the lessons of the

international existing landfill technologies, improving our own landfill technology and

developing the efficient stabilization agents of heavy metals; it is also urgent to

strengthen the supervision on fly ash treatment process and landfill operation,

improving the quality of fly ash landfill and ensuring high environmental friendliness

under the premise of meeting the processing capacity and cost control. It needs further

study in the technical application on how to solve the problem of heavy metal control

and poor stability. The amount of chemical agents is higher than the same type of

foreign products under the same treatment effect. In the future, it is also a must to

focus on the development of chemical stabilization technology with simple process,

good stability and relatively little investment. In addition, the high-temperature

vitrification technology has a high rate of volume reduction, with advantages such as

stabile properties of sediments and no heavy metals. However, how to reduce the

content of volatile heavy metals, and at the same time develop post-treatment process

of flue gas has become a key issue in improving the melting method.

604. As for resource utilization of the fly ash, it is viable to learn or introduce the

melting and solidification technology and heavy metal recovery technology from Japan

and Switzerland, and through absorption and re-innovation, to develop the fly ash

disposal technology and heavy metal recovery technology suitable for China's current

national conditions.

605. Draw lessons from the standardization system of fly ash disposal in developed

countries and perfect the standard system of China's incineration fly ash treatment,

disposal and resource utilization combined with the actual demand in China.

TA-8963 PRC Final Report Chapter VIII

248

CHAPTER 8 ASSESSMENT OF TREATMENT

/DISPOSAL TECHNOLOGIES FOR MSWI FLY ASH

606. In view of the characteristics and basic properties of the above-mentioned

MSW incineration fly ash, the research on its safe disposal and potential resource

utilization has become a common concern of domestic and foreign scholars. The

treatment and disposal of MSWI fly ash is essentially a risk management that aims to

keep the environmental and human health risks of pollutants within acceptable limits.

There are mainly two ways to control the risks. One is to destroy the pollutants by

sources, that is, to reduce the sources of pollution; second, to reduce the migration of

pollutants, that is, to cut off the ways of exposure. The risk of fly ash mainly comes

from the heavy metals and dioxins that are enriched in it. Dioxins, of which toxicity is

strong, have little content in fly ash and very low water solubility, so it is relatively easy

to control the migration of dioxins. However, the content of heavy metals in fly ash is

high, risk control of the most important.

607. At present, common domestic and foreign MSW incineration fly ash treatment

and disposal technologies are mainly divided into two aspects of land disposal and

building materials utilization, based on which the subdivision areas include cement

curing/stabilizing, chelating agent curing/stabilizing, high temperature melt

solidification, underground Storage, cement kiln co-processing, construction and

utilization as lightweight aggregates and more. In selecting a fly ash treatment /

disposal technique, a suitable technical assessment should be carried out. This

chapter mainly focuses on the technical evaluation of existing domestic and foreign fly

ash treatment technologies.

8.1 Qualitative Evaluation of Different Treatment Options

608. MSW incineration essentially concentrates pollutants dispersed in the

environment to be burned, removed and separated and concentrated, while fly ash is

the end product of pollutant separation and concentration. The above sections provide

a brief description of the different disposal technologies for fly ash. However, the

products of different schemes have their own unique physical and chemical

characteristics and their special environment and potential risks for storage. The

technical comparison as shown in Table 8-1.

609. At present, due to the advantages of low processing and investment cost, the


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addition of organic, inorganic or complex curing / stabilizing agents supplemented with

cement lime as a solidified substrate can improve the product strength, and the

stabilized product can meet the requirements of GB16889-2008 admission

requirements, followed by landfills in accordance with the specification of landfill, which

is the mainstream of MSWI fly ash disposal. In view of the adoption of different

chemical agents and curing processes, fly ash, which is solidified by using the

chelating agent in the manner of shot solidification, is a problem that needs attention

in the future. In addition, the landfill regulation pond leachate generated complex and

volatile water quality, the follow-up leachate treatment will undoubtedly increase the

difficulty.

610. Cement kiln co-disposal of incineration fly ash curing than the pharmaceutical

/ stabilization has some advanced technology, but also in line with the basic idea of

waste resources. However, this technology has a long path, high investment and

operating costs, and exposure to more risks in the technical aspects. The pretreatment

of water washing needs to consume a part of fresh water resources, and the generated

wastewater needs to be treated and reused or discharged to meet the standards. So

far, the popularization and application are still challenged by experts and scholars from

the field of environment and cement production. In particular, choosing a reasonable

and appropriate way to dispose of the kiln ash has a great impact on the harmless

effect of the fly ash. Take the construction experience of Japanese ecological cement

plant as an example, the construction cost of co-processing cement kiln is 3 to 4 times

that of normal cement production. There are sti ll further optimization necessary for

cement kiln co-processing incineration fly ash process, especially in the use of carbon

dioxide to regulate water quality, to reduce pretreatment wastewater treatment dosage,

potassium and sodium separation, to increase product added value, bypass ventilation

desalination, stable kiln conditions, which are necessary for technical optimization and

improvement, so as to further reduce disposal costs.

611. Relative to the above process, the harmless / building technology based on

melting and solidification of fly ash has few engineering practice in China and is still in

the pilot and demonstration stage. The relevant examples are mainly the melting and

curing aspects of nuclear waste and other difficult to deal with hazardous waste. In

contrast, the technology is more common in countries such as Japan. In Japan, for

example, there were 102 fly ash melting furnaces nationwide in 2014 with a capacity

of 320,000 tons/year. This means that almost all incineration ash is treated by melting

technology. According to statistics, the cost of Japan ash melting treatment is about

1000-1500 yuan/ton (according to the price of electricity have changed), while the

furnace mainly include resistance melting furnace, plasma melting furnace and burner


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melting furnace three. China’s MSW incineration fly ash contains high levels of alkali metals, chlorine and sulfur, which is not suitable for direct melt-solidification treatment

(requires chlorine content <2%), and requires some degree of pre-treatment or other

low-chlorine waste co-processing, which will increase the operating costs of the

process and process instability. Second, the fly ash melting needs to be heated to

above 1200 ℃, equipment investment and operation of high energy consumption.

Again, the high temperature process is likely to cause low-boiling heavy metal

volatilization. Based on the above constraints, how to improve the solidification rate of

heavy metals in the melting process, increase the thermal efficiency, reduce the energy

consumption and achieve low-temperature melt-solidification through additives, and

use the products produced in the melting process to manufacture high value-added

products(such as glass- grading purification of heavy metals in the tail gas) to control

costs will be the key link of melting process technology to deal with fly ash

breakthrough.


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Table8-1 Comparison and Selection of Different Fly Ash Disposal Schemes

Technical Solutions

Cement Solidification Chelator Solidification

Melting Solidification Cement Kiln Co-disposal Underground Storage

Auxiliary Materials Costs

Ordinary cement and auxiliary materials cost

are low

Chelating agent itself are high cost, and

dosage vary with the nature of fly ash

Waste glass can be used as a glass

additive, low cost

As a raw material for cement production, do not need additional materials

Do not need additional materials

Auxiliary Material

Consumption

Incineration fly ash and the quality of the

cement consumed in is about 2: 1

Chelating agent dosage is about 1%-3% of fly ash quality

The amount of supplies is determined by the degree of vitrification

required

Not needed Not needed

Preprocessing or Not

Not needed Not needed Need to minimize the content of chlorine in fly

ash

Washing pretreatment, into the kiln material chlorine

and fluorine content should not exceed 0.04% and

0.5%; required fresh water is 0.7-10 t/t fly ash

Not needed

Fly Ash Physical Statue

Changed Changed Changed Changed Not changed

Effect Ordinary solidification effect, long term stability issues

Good solidification of heavy metals, limited effect of dioxin control

Highly stable vitreous formed, completely destroyed dioxins

Dioxin substances are destroyed; part of the

heavy metals are fixed

The safest way, long term stability is

guaranteed

Equipment Requirements

Mechanical equipment costs low

High cost of machinery and equipment

Need special equipment, high cost

Pre-treatment investments costs high

Special geological conditions

Operational Requirements

Operation and management is simple,

General operation and management, safety is

Need professional operators to manage,

Need professional operators to manage, good

Need professional operators to


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good security good safety in general safety manage, good safety

Investment Low investment Relatively high investment

High investment Investment is 3-4 times of normal cement production; tail gas treatment facilities need to be improved and

strengthened

High investment

Operating Costs Relative low Low operating costs Consume a lot of energy, high operating

costs

Energy consumption comes mainly from the

cement

Low operating costs

Environmental Risk

The solidification of heavy metals, such as Cd and Zn, in fly ash

are hard. The increase of salt content will

damage the solidified body, reduce the

strength, increase the permeability

The stabilizing effect on dioxin is small, dioxins

enter the landfill

Need some pretreatment process, and supported flue gas

purification device; relatively high material

requirements, some heavy metals and alkali salts into the secondary

fly ash

Need to supported flue gas purification device; kiln ash

handling more complex, need attention (accounting for 20-50% of the original

heavy metals); water treatment stage mud cake also need to back to the

kiln

No engineering demonstration in china. It is mostly

used for the isolation disposal of high-level nuclear

waste

TA-8963 PRC Final Report Chapter IV

253

8.2 Quantitative Comparison and Selection of Different

Treatment Options

612. In order to better reveal the treatment effect and risk control effect of the above

technologies on MSW fly ash, the content of this section uses the method of multi -

dimensional indicators, from the expansion coefficient of the product after treatment,

the environmental risk of the treatment process, the total heavy metal leaching

Quantitative control efficiency and the economic value of material recovery and other

aspects of the various treatment / disposal technology advantages and disadvantages

of quantitative comparison, with a view to screening for different technologies to

provide more intuitive data support.

8.2.1 Volumetric Reduction Efficiency

613. The size of the product to be treated directly affects the footprint and service

life of subsequent waste storage sites (eg, safe landfills). The reduction efficiency of

fly ash was treated as (1 – treated waste volume / raw fly ash volume) * 100%. Fly ash

cement product volume after curing significantly increased, generally considered after

the treatment waste conversion ratio of 1.5 to 2, here based on 1.75 calculation. In

contrast, organic chelating agent for the fly ash volume increases is not obvious,

Whether it is the use of solid chelating agent and liquid chelating agent can achieve

little or no compatibilization of the basic capacity, so that the expansion factor of 1.

One of the advantages of melt-solidification technology is to significantly reduce the

amount of fly ash, the resulting vitreous (waste) Capacity reduction up to 80%. Cement

kiln co-disposal incineration fly ash as a raw material into the cement production, in

theory, for fly ash capacity reduction efficiency is up to 100% (kiln dust back into the

kiln or doped to cement clinker). In addition underground storage does not change the

physical form of the fly ash itself, so it has no effect on the amount of fly ash. The

above discussion of the results of the comparison shown in Figure 1. As can be seen

from Figure10-1, cement kiln co-processing and high-temperature melting have the

best effect on the volume reduction of fly ash, while the cement reduction has the worst

effect.


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Figure8-1 Different Disposal Technologies on the Fly Ash Volume Reduction

Effect

8.2.2 Environmental Risks of Treatment / Disposal

614. At present, cement / chelator solidification / stabilization process + landfill, as

the main technical option for incineration fly ash disposal in China, has more

mechanized equipment and operation and less environmental risk in the whole curing

process. The main environment risks arise from potential fugitive dusts from raw

materials and products (eg fly ash, acceptance and storage of mixing and mixing of

refineries, transfer points, conveyors, transport vehicles, etc.) and dust from landfills of

unformed cured products. In addition, there is a risk of leaching of heavy metals and

leakage of leachate due to the need to add some external water and workshop and

equipment rinse water during the curing operation. However, this part of the production

of sewage generated a very small amount of total can be considered into the landfill

leachate treatment system. The separation of production workshop, control room and

office space also fully guaranteed the occupational health of staff and the dust

generated had less impact on the environment around the factory.

615. The risks of dusting and the risk of heavy metals in flushing water during the

operation of different disposal technologies are similar and will not be repeated here.

In contrast, cement kilns co-processing household waste incineration fly ash and melt

solidification technology route longer, more intermediate links lead to more risk

exposure points, increasing the difficulty of pollution control. The pretreatment of water


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washing is an essential part of co-processing of cement kiln. The whole pretreatment

process involves the storage of fly ash, the washing of fly ash, the solid-liquid

separation system, the drying system, the sewage treatment system (sewage

pretreatment + core processing unit) system. The water-cement ratio in the washing

process is generally 1 to 10: 1, resulting in a relatively large amount of washing waste

liquid. Washed wastewater is mainly composed of alkali chloride, while it also dissolved

some of the heavy metals such as Cd, Cr, Cu, Pb and Zn, according to the different

types of heavy metals content at the level of 0.008-10 mg/L, of which dioxin

concentration is relatively small. Some heavy metals exceed the wastewater discharge

standards and must be treated before they can be recycled or discharged. The

combination of pretreatment and evaporative desalination may effectively recover the

chloride salt from wastewater and allow for full reuse of the evaporative water, but the

energy consumption of this process is roughly equivalent to the electrical energy

generated by the amount of rubbish that this portion of fly ash burns . In addition, flue

gas and cement kiln exhaust gas discharged through the kiln foot bypass contained a

certain amount of heavy metals and dioxins, but the concentration and total amount

were relatively low (0.0003 to 0.03 tons/year for different heavy metals; British at 0.03-

0.04 tons / year). Overall, due to the existence of waste water and waste gas collection

and disposal system during the operation of cement kiln disposal process, the

theoretical discharge of heavy metals and dioxin substances is relatively small and the

environmental risk is low. However, the long process route increases the possibility of

unexpected accidents in the processing sector. In the case of fault operation, the

emission concentration of toxic substances can increase by tens of times and the

environmental risk increases significantly (Figure 8-2).

Figure8-2 Environmental Risk Sources for the Co-processing of Fly Ash and

Cement Kilns


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8.2.3 Control Efficiency of Total Heavy Metal Leaching in Product

616. Due to the different pretreatment process and the addition of auxiliary

materials led to product weight gain ratio is not consistent in fly ash disposal process.

Although the application of different technologies has obvious control effects on the

leaching concentration of heavy metals, the total amount of heavy metals actually

solidified by each technology theoretically still has a certain gap because of the dilution

effect. The heavy metal leaching total amount control efficiency of the product on

behalf of the ability to isolate the environment and heavy metals stabilized by different

technologies, and Reflect the real control ability of different disposal ways of fly ash.

The above expression for assessment can be simplified to (1 – the total amount of

heavy metal leaching products after the original fly ash heavy metal leaching) * 100%.

617. Under the premise of good geological conditions, the probability of the storage

and underground storage methods, in theory, direct contact with the water environment

is very low, and there is no external conditions of heavy metal leaching, so its isolation

of heavy metals and the environment in theory should be 100% . In contrast, the

cement / chelator / melt-stabilization + sanitary landfill approach exposes the product

to leachate, potentially causing heavy metal leaching. The weight gain ratio of lime

curing and chelating agent curing is generally about 1.5 and 1.2, and the leaching

concentration of heavy metal in the solidification body is basically at and below the

level of 0.001 (unit: mg/kg). However, comparing the leaching concentrations of heavy

metals from the original fly ash and fly ash solids, the stabilization efficiency for cement

and chelator hardened solids is only 83% and 90%, respectively. Therefore consider

the dilution effect of raw materials, its actual heavy metal curing efficiency is only 75%

and 88%.

618. With reference to the relevant literature, the leaching concentration of heavy

metals from clinker produced by cement kiln co-processing fly ash is relatively low.

Taking Pb, Cd, Hg and As as examples, the leaching concentration can reach 0.001

level and below, similar with the ordinary cement. Although the dilution ratio is larger

(ash fly dosage 3-10%), but on the whole, the stabilization efficiency of heavy metals

can still reach 98-99% or even more, and harmless effect is more ideal. In addition, it

should also be noted that about 20-50% of heavy metals are volatilized into the kiln

ash according to the types of heavy metals during the co-processing process. This part

of the volatile products are mainly low-boiling heavy metals such as Cd and Pb, Its kiln

ash up to the proportion of the original fly ash content of about 50 to 80%. Therefore,

with the direct addition of kiln dust into the clinker, this part of the highly toxic heavy


257

metals will only be solidified and sealed by subsequent cement hydration, which will

significantly increase the total amount of leaching (to About 13%, for example, the

actual cement curing rate is only about 75%). The analysis of the control effect of the

total amount of heavy metals in the melt-solidified process is similar to that of the

cement kiln co-processing. The leaching risk of the solid product (molten solid) is

negligible (heavy metal leaching concentration <0.0001 mg / kg) of the vitreous itself,

its heavy metal leaching and fixing efficiency of approximately 100%. The safety of the

technology is mainly focused on the secondary fly ash subsequent processing. Data

show that in the melting process, fly ash weight loss as high as 35-40%, volatile heavy

metals mainly in the form of chloride escaping.

619. Based on the above analysis, the results shown in Figure 10-3. It can be seen

from the figure that if the kiln dust in cement kiln process is directly mixed into cement

clinker, the control effect on the total amount of heavy metal leaching drops

significantly. Therefore, the proper disposal of secondary fly ash is the key to improving

the overall effect of cement kiln technology and high-temperature melting technology

on the harmless disposal of fly ash.

Figure 8-3 Effect of Different Fly Ash Disposal Technologies on Total Heavy

Metal Leaching Products

(The blue line indicates the fixing effect of the fly ash cured product itself and the

red line indicates the mixed kiln ash clinker and the high temperature molten

secondary fly ash cement)


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8.2.4 The Economic Value of Resource Recovery

620. Among the above-mentioned several types of fly ash disposal technologies,

only the cement kiln co-disposal process has significant resource effect. However, it

should be pointed out that fly ash must be pretreated with water to pre-treat

dechlorination, sulfur and alkali metals before entering the cement kiln co-processing.

The remaining solid phase material only includes inorganic materials such as silicon,

aluminum, iron, calcium and magnesium Compounds and some heavy metals, without

any flammable substances. Therefore, as an alternative raw material, only some of the

clay for cement ingredients can be saved. There is no possibility of providing a

substitute for combustion energy. However, the price of clay itself is relatively low, and

its use cost is directly related to transportation costs. Therefore, the economic value of

using fly ash as an alternative raw material should include two parts of clay +

transportation, which is very limited. Available data show that in the case of energy

substitution (calorific value), the cost of co-processing of solid waste per tonne of

clinker by cement kilns will increase by 2.88 yuan, indicating that the cost of cement

products brought by the direct co-processing of fly ash will be even more Increase to

a large extent (co-processing part only). It is reported that in 2015, Beijing Jinyu Liulihe

Cement Co., Ltd. Built the first MSWI fly ash disposal line officially passed the

environmental inspection in Beijing, Liulihe Cement Plant annual disposal of 20,000

tons of fly ash into the plant dry chlorine base of 22%. Therefore, the cost of disposal

is very high and the cost is about 1,500 yuan / ton, while the subsidy from Beijing

municipal government is as high as 1,320 yuan per tonne of fly ash. Therefore, the

economy of cement kiln co-processing fly ash is discussed from the viewpoint of waste

utilization value is not appropriate, the high financial subsidies in other citi es and

regions less likely to be realized.

621. On the other hand, the products produced by the melt-solidification of fly ash

have the possibility of further resource utilization. By adding other auxiliary substances

using melt-solidified solid-phase material to produce glass-ceramics or other high

value-added by-products. Meanwhile, in the case of small amount of flue gas, the

separation and recovery of high-grade heavy metals in the exhaust gas are realized

as much as possible so that value will largely subsidize operating costs and achieve

gains. On the other hand, the development of low-temperature melting technology,

through the promotion of flux and catalyst investment to reduce the temperature

required for high-temperature melting, thereby increasing the low-boiling point of heavy

metal solidification rate, lower operating energy consumption and power consumption,

melt stabilization technology to control the overall cost. However, in summary, the


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technology still has the problem of over-running at this stage and is only suitable for

promotion and utilization in developed countries.

622. In summary, the current stage of different disposal methods for the control of

incineration fly ash is mainly reflected in the reduction and harmless aspects, but the

characteristics of the resource utilization of each technology is not obvious, not as a

technical screening starting point discuss.

8.3 Summary

623. MSW incineration essentially concentrates pollutants dispersed in the

environment to be burned, removed and separated and concentrated, while fly ash is

the end product of pollutant separation and concentration. From a risk management

point of view, “zero landfill” runs counter to the basic law of “material balance” and is not practicable in practice and does more harm than good to environmental protection.

Solidifying and stabilizing the landfill according to local conditions (in the long term, we

can consider drawing on German experience to promote underground storage) can

effectively cut off exposure to heavy metals and dioxins to achieve the goal of

minimizing environmental risks. This is also the realistic choice of China’s MSWI fly ash treatment, which contains correct idea, effective scheme, and controllable cost.

624. It is not suitable to discuss cement kiln co-processing incineration fly ash from

the perspective of resource utilization. Complex processes consume large amounts of

energy and materials while creating new uncontrolled wastewater and waste gases. In

the process of domestic waste treatment through multiple links, it pays a great price to

enrich the relatively stable small amount of solid residues in the toxic pollutants

released to water, atmosphere and soil and other environmental media, forming a

“reverse pollution control.” Second, heavy metals, which are characteristic pollutants

of fly ash, can not be eliminated but rather returned to the environment and people in

the form of products (cement), thus facing the problem of “shifting” the problem of handling fly ash generated by contemporary people to the next generation has become

the waste disposal issue that the next generation must face. Based on this, although

the reduction effect is obvious, cement kiln co-processing fly ash does not fully meet

the basic requirements of environmental ethics. If there is no obvious economic

advantage, the process route needs to be further optimized and improved, which is not

enough copy promotion. In particular, kiln dust in cement kilns should be managed in

accordance with hazardous waste and should not be simply mixed back into cement

clinker, which will significantly reduce the effect of this technology on heavy metal


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control.

625. The main hazardous substance of MSW incineration fly ash is heavy metal.

The main objective of fly ash treatment is to control the environmental risks of heavy

metals. Therefore, the utilization of fly ash in the environmental ethics resources must

be separated and recycled simultaneously, otherwise it is the cart before the horse.

Fly ash melting has certain potential for separation and recovery of heavy metals. By

properly handling the secondary fly ash generated in the melting process, fly ash

melting not only improves the overall process control ability of re-contacting heavy

metals and environmental media, but also recycles high value-added products To

subsidize the operating costs of the process, it is the possible development of the

utilization of fly ash resources.

626. Finally, for the control of the environmental risk of domestic MSW fly ash, we

must not take it for granted with rough considerations and prevent the resource

utilization only looking for short-term benefits.


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CHAPTER 9 TECHNICAL SUGGESTIONS ON THE

SUSTAINABLE MANAGEMENT OF MSW

INCINERATION FLY ASH IN CHINA

9.1 Fly Ash Management and Technology Selection Principles

627. The management of hazardous wastes is essentially the management of risks,

which aims at controlling the environmental risks of pollutants within the acceptable

ranges. There are two approaches for the control of environmental risks - one is to

destroy the pollutants from the origins, i.e., to reduce the strength of pollutants’ sources while the other is to reduce the pollutants’ transferability, i.e., to cut off its exposing path. The main risk of fly ash origins from the heavy metals and dioxins collected from

hazardous wastes. Dioxins have strong toxicity, but there are only slight dioxins in fly

ash and they have low water-solubility as well. controlling its transferability is therefore

not that difficult. However, a lot of soluble heavy metals can be found from fly ash,

which should be given the top priority.

628. In accordance with the requirements of sustainable development, the most

ideal approach is to conduct resources utilization absolutely, safely and economically

while dealing with incineration fly ash, as illustrated in Figure 8-1 However, such goal

is unachievable currently. Achieving regulative and scientific sustainable management

of fly ash is a continuously improving progress. The selection of technology and

management of fly ash should stick to the following principles:

❖ Emphasis on Personnel Training: We should also promote the research

discussion, technical communication and cooperation with foreign scholars,

research authorities and enterprises. Furthermore, we need to hold regular forums

and meetings, establish special funds and increase the training and talents as well.

❖ Emphasis on Developing Innovative Technology: we should encourage and

support the development and application of incineration fly ash’s resources utilization, especially the construction of actual engineering projects.

❖ Emphasis on Whole-process Supervision: The whole process of production,

storage, transportation and final disposal / utilization of incineration fly ash must

be managed. Emphasis should be placed on the source reduction of incineration

fly ash, reducing spilled and spilled fly ash during storage and transportation so as


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to realize the environment harmless disposal and utilization.

❖ Expert Review for Choosing Technology: supervise and urge incineration

plants’ operators to properly treat and dispose incineration fly ash, evaluate its treatment and disposal technologies and organize experts for review.

❖ Choosing Technology Based on Economy: the unit cost of different fly ash

disposal technologies is huge, from hundreds to thousands per ton. Therefore,

when choosing the treatment technology, local economic development level and

affordability must be fully considered.

❖ Choosing Technology according to Location: huge environmental and

economic distinction exits between diverse regions brought by China’s vast territory, so the treatment and disposal of incineration fly ash should be targeted

at diverse regional situations and choose the corresponding fly ash disposal or

resources utilization approaches in the light of local conditions. For instance, the

population density in central area is relatively high while the rainfall amount is

smaller than that in eastern and southern region and the soil quality is better than

that in the eastern part. It therefore costs mush less to build safe landfill plants and

sanitary ones there. Currently, industries like construction materials with mature

fly ash resources utilization is the main source of energy consumption and air

pollution while pollutants in the mountainous central area are hard to be diluted,

so the preferred sanitary landfill plants should be located here.

❖ Choosing Technology Suitable for Infrastructure Construction Status: when

infrastructure construction scale is large and the construction process is rapid,

great amount of construction materials are needed, offering broad market for the

fly ash’s resources utilization products. So in this stage fly ash utilization technologies for construction material is suitable. Along with the acceleration of

the modernization process as well as the improvement of basic infrastructures in

China, the market’s requirements towards construction materials will surely be lowered and this industry’s fly ash treatment amount will be decreased as well. So

alternative technologies for fly ash disposal and resource utilization is needed to

meet the needs for urbanization.

❖ Emphasis on Pretreatment Technologies: diverse hazardous substances can

be found from MSW incineration fly ash, especially volatile components.

Pretreatment has great impact on resource utilization and therefore, great

attention should be paid on the pre-treatment before fly ash’s resources utilization,


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such as pre-washing to remove chloride from fly ash, etc.

Figure 9-1 Flowchart of the Substances and Energy Circulation

629. Analyzing from international fly ash’s disposal experience and actual situations nationwide over years, the maximum fly ash’s resources utilization will be the future goal and trend. MSW incineration fly ash has complicated properties and

causes high-level harms, whose technical route for treatment should be overall

organized, systematically designed, carefully selected to control risks and guarantee

the harmlessness while considering about resources comprehensive utilization.

9.2 Technology Suggestions Suitable for China’s Current

Situation

9.2.1 Solidification and Stabilization – Sanitary Landfill

630. Normative landfill disposal in accordance with the actual conditions after

solidification and stabilization can effectively cut off the exposure pathways of heavy

metals and dioxins so as to realize the goal of minimum environmental risk. When

appropriate operation of a final disposal site is considered, chemical insolubilization

(inorganic or organic chelate) of fly ash is one of the most effective and economical

methods. When standards for the environment of the site after its closure and

decommission is concerned, however, it is necessary to clarify the effect of chelating

agent on the leachate and decomposition products of chelate compounds. To respond

to the above concern, it is desired to set chelating agents use standards that oblige


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new chelating agents to be inspected, assuming standards are set for

decommissioning of final disposal sites. Fly ash melting mixed with slag should not be

recommended in terms of high energy consumption and cost effectiveness. But in

some municipalities where local electric furnace businesses exist, it may be effective

to conduct ash to slag processing and metal recovery in combination with dedicated

reductive dissolution facilities. Actually such businesses in Japan are actively engaged

in incineration residue treatment for the municipalities that do not own final disposal

sites. In any cases, melting treatment of only fly ash should not be recommended.

9.2.2 Sintering Technology

631. The incineration fly ash molded body is heated at a temperature lower than

its melting point, so that the material spontaneously fills the particle gap and densifies,

resulting in an increase in the density and strength of the molding, and becomes a

whole having a certain performance and a geometric shape. The compressive strength

of sintered solidified body satisfies the requirement of coarse aggregate strength in

concrete. Fly ash sintered solidified body can be used as admixture in concrete. And

fly ash in the sintering process effectively curing a variety of heavy metals, sintering

process manufacturing materials more economical and safe. However, the fly ash is

required to be pre-treated by washing, otherwise the fly ash in the sulfate, chloride and

vitreous on the curing process is extremely detrimental.

9.2.3 Cement Kiln Co-treatment

632. Eco-cement making is a recycling method, using silica dioxide, alumina oxide,

iron trioxide and calcium oxide from fly ash while other hazardous substances can still

lay influence upon the environment during the production and using process. It is a

viable option for a municipality where generation density of incineration residue is high.

A cement plant can accept fly ash only as far as it is operated with technology to

remove alkali salts form fly ash. Product quality standards for eco-cement still need to

be established.

9.2.4 High-temperature Melting

633. Adding the mixture of fly ash or fly ash to glass frit to a melting temperature of

1000 to 1200 °C and controlling the atmosphere of the furnace to prevent the

volatilization of heavy metals so that the solid particles in the fly ash undergo a melt

phase change and become liquid slag rapid cooling to form a dense glassy slag, with


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the vitreous dense crystal structure of the fly ash firmly enclosed in the vitreous.

634. The technology has the advantages of weight loss and reduced capacity, and

can generally lose about 2/3. After melting, the heavy metal is firmly bound in the

network structure of SiO2 silicon tetrahedron, and the leaching rate is low, which can

meet the current leaching standard. However, the glassy material obtained by high

temperature melting of fly ash has poor hardness and thermal performance. It can only

be used for roadbed materials, cement concrete mixed materials or re-landfill landfill.

The added value is low, and the melting process will produce A small amount of high

concentration of melting furnace fly ash (the Cd and Pb concentration is 5 to 10 times

before melting); high slag, cement, concrete will cause alkali corrosion; cost is very

high. Base on experiences in Japan, fly ash melting mixed with slag should not be

recommended in terms of high energy consumption and cost effectiveness.

9.2.5 Heavy Metal Recovery

635. Taking note of such fly ash components as alkali salts and metal salts like

zinc, lead etc. it is promising to employ metal recovery method by water-washing

before the smelting process in the municipalities where metal smelter business are

located. In some municipalities where local electric furnace businesses exist, it may be

effective to conduct ash to slag processing and metal recovery in combination with

dedicated reductive dissolution facilities. Actually such businesses in Japan are

actively engaged in incineration residue treatment for the municipalities that do not

own final disposal sites. In any cases, melting treatment of only fly ash should not be

recommended.

9.2.6 Colloidal Filling and Mining Collaborative Resource Utilization

Technology

636. Cemented filling and mining collaborative resource utilization of waste

incineration fly ash technology is suitable for co-processing household waste

incineration fly ash and mining waste of mining, separation, and metallurgical. The core

is the cementitious system of tailing-steel slag-gypsum-waste incineration fly ash as

the cementitious materials of mine filling, the waste of mining, and separation as

aggregate, adding water reducer admixture and water mixing qualified solid waste

cementing filler.

637. Colloidal filling and mining collaborative technology of the waste incineration


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fly ash takes full advantage of the "silicon four-coordinate isomorphic effect" and the

"double-salt effect." Ettringite (Ca6Al2(SO4)3•(OH)12•26H2O) is the most common

double salt mineral in ordinary cement concrete and the most common double salt

mineral in the cementing and filling hardened bodies of most subterranean mining.

Solubility constant of ettringite is 1.1 * 10-40. The results show that the saturated

aluminum ion concentration of ettringite in water is more than 10 times lower than the

saturated aluminum ion concentration of water-quenched blast furnace slag powder in

water. Thus in a system with sufficient supply of Ca2+, OH- and SO42- ions, the

crystallization of ettringite will continue to promote the dissolution of the aluminum oxy

tetrahedra in the water-quenched blast-furnace slag micropowder from the vitreous

network of the slag. The links of the Si-Al-O tetrahedrons, which promote the higher

degree of polymerization in the slag, are destroyed, forming a large number of active

organosilicon tetrahedrons or siloxane tetrahedrons. Slag for the cementitious system

to provide Ca2+, OH- and a small amount of silicon tetrahedron. Mg2+ and Fe2+ of slag

in the gelled system and Ca2+ similar role. A larger amount of gypsum for the system

to provide a steady stream of Ca2 + and SO42-.

638. The main components of MSW fly ash are inorganic substances and heavy

metals produced after MSW incineration. When the flue gas is purified by dry or semi-

dry reaction, some reaction products (such as CaCl2 and CaSO4) and partly incomplete

Reaction of Ca(OH)2 and other substances are contained. It can provide a large

number of Ca2+, OH- and SO42- for the gel system. At the same time, there is a high

content of Cl- in the incineration fly ash, which forms hydrated calcium chloroaluminate

hydrate hydrate in the slag hydration process. Chlorine salt will form alkaline

substances such as NaOH in the slag hydration process, Improve the liquidity alkalinity

and promote the further hydration of slag.

639. Colloidal filling and mining collaborative utilization technology of waste

incineration fly ash solidifies the heavy metals in fly ash of cementitious materials

during the hydration of cementitious materials. The main hydration products of

cementitious materials are ettringite, CSH gel and Zeolite minerals, etc. Several

products contribute to the system's solidification of heavy metals. Heavy metal

elements can be isotropically incorporated into the ettringite lattice and C-S-H gel has

a strong ability to adsorb heavy metals. On the other hand, the Lead-alum double-salt

minerals, such as arsenic-lead alum-alum lead alum-like complex salt (Pb, H+) (Al3+,

Fe3+, Fe2+)3 (SO42-, AsO4

3-)2(OH), can also rapidly consume the Al3+, Fe3+, Fe2+, OH-

and SO42- ions in solution with the participation of arsenic and lead compounds, thus

also promoting the consumption of slag powder, slag powder and gypsum in the

system. Such complex salts in water solubility is extremely low. At higher pH, the


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crystallization of such double salts allows both arsenic and lead concentrations in water

to reach drinking-water standards. Recent studies have also shown that arsenic and

lead can be highly charged into the hydrous aluminosilicate network of the zeolite-like

phase or become highly charged as part of the network backbone. In addition, this

technology cut off the route of its pollution transmission through the method of physical

wrapping. In particular, the solidified system formed by the slag-based cementitious

material-waste incineration fly ash hydration reaction contains a large amount of CSH

gel, and its compact structure can reduce the overall solidified body permeability, which

contains dioxin particles wrapped fixed.

640. Colloidal filling and mining collaborative resource utilization technology of

waste incineration fly ash not only reduces the accumulation of solid waste such as

metallurgical slag, but also reduces the filling costs of filling enterprises in the mine,

but also realized the recycling of heavy metals hazardous waste incineration fly ash

Use, and can save landfill. If the industrialization of colloidal filling and mining

cooperative utilization of waste incineration fly ash technology is realized, the two

industries of fly ash disposal and mine filling can be organically integrated, at the same

time, it will bring about employment in Beijing, Tianjin and Hebei Province.

9.2.7 Fly Ash Source Reduction Technology

641. This method can not be underestimated by reducing the amount of waste

entering the waste incinerator through the waste source classification directly and

significantly reducing the amount of fly ash generated.

642. In addition, improving the solid reagents of flue gas treatment can reduce the

amount of fly ash. According to China's Standard for pollution control on the municipal

solid waste incineration (GB18485-2014), the 24 hour mean limit value of HCl is

reduced from 100 mg/m3 (GB18485-2001) to 50 mg/m3, and the EU 2010 standard

requires the emission limit of HCl value should not exceed 10 mg/m3. In order to ensure

that the flue gas discharge standards, waste incineration enterprises generally adopt

excessive spraying Ca(OH)2 pulp or the original semi-dry method based on the

addition of dry Ca(OH)2 deacidification means. According to the survey data, the ratio

of Ca(OH)2 consumption to fly ash production is as high as 1: 2 on average, ie Ca(OH)2

contributes about 50% of fly ash, which not only leads to flue gas treatment Increasing

costs also lead to an increase in the amount of fly ash and the difficulty of stabilizing

the fly ash. In order to increase the stabilization of heavy metals in fly ash, the use of

chelating agents alone and the processing costs of power plant will be significantly

increased, and it is difficult to ensure that the safe disposal of fly ash 100% pass the


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goal.

643. In the process of removing HCl with Ca(OH)2, the main factors affecting the

deacidification effect are CaO content in Ca(OH)2, CaO activity and digestion rate.

Reference from Japan's successful experience in flue gas treatment, the use of high-

activity calcium hydroxide and sodium bicarbonate as flue gas deacidification practices,

ensure that the stability of waste incineration flue gas standards, and have great

practical significance in reducing the amount of fly ash from the source and the difficulty

of stabilization treatment.

644. The use of high activity calcium hydroxide instead of ordinary calcium

hydroxide deacidification agent for semi-dry system flue gas deacidification, the use of

sodium bicarbonate instead of calcium hydroxide for dry system depth deacidification

from the source control can reduce the amount of fly ash generated, reduce the

fluctuations of the physical and chemical properties of fly ash, and reduce the difficulty

of handling fly ash.

9.2.8 Pollutant Reduction Technology - Waste Classification Technology

645. In recent years, with the increase of urbanization rate, the content of organic

matter in municipal solid waste tends to increase gradually, and the content of

inorganic matter such as muck and soil gradually decreases. The average content of

organic and inorganic substances gradually becomes stable and the composition

changes little. The proportion of recyclable materials such as paper, plastic and rubber

increased greatly, the usable value of rubbish increased, the combustible material

increased and the calorific value increased to a certain extent. With the popularization

and implementation of trash bags in various cities, Rain erosion, coupled with changes

in people's lifestyle, waste moisture content will gradually decline.

646. Change the waste collection method from mixed collection to source

classification and collection. At first, the household waste is divided into "harmful

waste", "recyclable waste", "kitchen waste" and "general waste", then "general waste"

Incineration, waste reduction from source and recycling can be achieved. First, reduce

the amount of domestic waste entering the incineration plant to reduce the amount

of incineration fly ash and ease the disposal pressure of fly ash; the second is to reduce

water content, which increase waste heat value, incineration temperature, and energy

efficiency to reduce the generation of dioxins; third, the reduction of metal content in

the waste can reduce the heavy metal content in fly ash. Therefore, the source

classification can directly reduce the formation of dioxins and destruct the formed


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condition of dioxins in the incineration process. At the same time, waste classification

can help incineration, can play a role of quantity reduction (to reduce waste disposal),

emission reduction (to reduce emissions), improve (improve combustion conditions),

improved efficiency (improve power generation efficiency) and so on.

647. The effect of waste separation on the reduction of fly ash pollutants was

verified by comparing the levels of heavy metals in incineration fly ash from mixed

municipal solid waste collection of China and incineration fly ash from Japan. Table **

gives the contents of heavy metals in fly ash from China and Japan. From the table **

can be seen:

648. China: The contents of heavy metals Cd, Cr and Ni in fly ash are very low

while the contents of Zn, Cu and Pb are generally high. According to Chinese literature

statistics, the contents of heavy metals in fly ash in China are quite different, and the

distribution of heavy metals is large. The difference between maximum and minimum

contents of Cu, Pb, Cd, Cr and Ni are three orders of magnitude, and the maximum

and the minimum of Zn two orders of magnitude. The average content of Zn was

highest of 8159.29 mg/kg, Followed by the average content of Pb and Cd was the

smallest, which was 119.55 mg/kg. The average of six heavy metals followed the rule:

Zn> Pb> Cu> Cr> Ni> Cd.

649. Japan: The contents of heavy metals Cd and Ni in fly ash are very low, while

the contents of Zn, Cu, Pb and Cr are relatively high, which is slightly different from the

distribution of heavy metals in fly ash. Japanese literature data also show that there is

also a large difference in the content of heavy metals and the content distribution range

in Japanese fly ash, in which the maximum and minimum content of Cu, Pb, Cd, Cr

and Ni differ by two orders of magnitude, and the maximum difference of Zn between

the maximum and the minimum by three orders of magnitude, which is similar to our

inland areas. Among them, Zn had the highest average content of 6856.34 mg / kg,

followed by Pb and Cd with the lowest average content of 67.35 mg / kg, followed by

Zn> Pb> Cu> Cr> Ni > Cd, with the same distribution of heavy metal content in China's

fly ash.


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Table 9-1 Basic Situation of Heavy Metal Content in Fly Ash from China and Japan

Nation Element Zn Cu Pb Cd Cr Ni

China

Content

Range(mg/kg) 300-71628 12-16404 31-21701 0.21-832 1.19-5116 1.23-2520

Average

Content(mg/kg) 8159.29 1321.52 3192.02 119.55 564.91 226.46

Japan

Content

Range(mg/kg) 82.01-24900 57-3650 12-4590 9-185 12.65-2055 1-977

Average

Content(mg/kg) 6856.34 1137.93 1877.56 67.35 264.34 147.85

650. By comparing the data in Table 8-1, it can be found that both heavy metals

highest content and average content of fly ash from China are much higher than that

from Japan. In order to clarify the differences between heavy metals in fly ash from

China and Japan, the average heavy metal content in fly ash in China and Japan is

compared and analyzed. The results are shown in Figure 8-2. As can be seen from

Figure 8-2, the average levels of six heavy metals in Japan fly ash are lower than those

in China. The main reason for this phenomenon is related to the waste collection

management. China's waste management system is not rigorous, and the waste mixed

collection, making heavy metals in a high content in the mixed waste, which directly

lead to high levels of heavy metals in fly ash. Japan's strict waste management, better

source classification, less mixed heavy metals in the waste incineration, make fly ash

in the lower content of heavy metals. It can be seen that the classification of waste on

the heavy metal content of fly ash have a great impact.

Zn Cu Pb Cd Cr Ni0

1000

2000

3000

6000

7000

8000

9000

Ave

rag

e C

once

ntr

atio

n(m

g/k

g)

Heavy Metal Element

China

Japan

Figure 9-2 Comparison of Average Heavy Metal Content in Fly Ash from

China and Japan


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651. Therefore, it is recommended to refer to the Japanese classification model.

Currently, the classification of waste in China can be divided into four categories:

"harmful waste", "recyclable waste", "kitchen waste" and "general waste", and "general

waste" can treat throgh incineration. This will not only greatly reduce the amount of

waste incineration, but also minimize the heavy metal content of incineration fly ash,

but also indirectly reduce the generation of dioxin in fly ash.

9.3 Prediction on the Environmental Impact

9.3.1 Mitigation Measures on Environmental Pollutions Caused by Poor

Management

652. The management of hazardous wastes is essentially the management of risks,

which aims at controlling the environmental risks of pollutants within the acceptable

ranges. There are two approaches for the control of environmental risks - one is to

destroy the pollutants from the origins, i.e., to reduce the strength of pollutants’ sources while the other is to reduce the pollutants’ transferability, i.e., to cut off its exposing

path. The main risk of fly ash origins from the heavy metals and dioxins collected from

hazardous wastes. Dioxins have strong toxicity, but there are only slight dioxins in fly

ash and they have low water-solubility as well. controlling its transferability is therefore

not that difficult. However, a lot of soluble heavy metals can be found from fly ash,

which should be given the top priority.

653. There are three disposal approaches with professional standards and

specifications related to MSW incineration fly ash in China: firstly, it should satisfy the

requirements stipulated by Pollution Control Standards for Hazardous Wastes Landfill

(GB 18598-2001) after solidification and then be sent to the hazardous wastes landfill

plants; secondly, it should satisfy relevant requirements stipulated by Pollution Control

Standards of MSW Landfill Plants (GB16889-2008) after treatment and then be sent

to MSW landfill plants for landfilling disposal; thirdly, in accordance with the stipulations

of Pollution Control Standards for Hazardous Wastes Landfill (GB 18598-2001),

Landfill Pollution Control Standards of Municipal Solid Wastes (GB16889-2008), Solid

Wastes Pollution Control Standards for Cement Kiln Co-processing (GB 30485-2013),

Solid Wastes Technical Specifications for Cement Kiln Co-processing (GB 30760-

2014) and Solid Wastes Environmental Protection Technical Specifications for Cement

Kiln Co-processing (HJ/T 662-2013), cement kiln co-processing should be adopted to

dispose fly ash; another resources utilization approach is the sintered ceramsite


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technology for fly ash. Relevant details can be found from Pollution Control Standards

for Hazardous Wastes Incineration (GB18484-2014) and Engineering and

Construction Technical Specifications for the Centralized Incineration Disposal of

Hazardous Wastes (HJ /T 176-2005).

654. The most reliable disposal approach is to send hazardous wastes into the safe

landfill plants after solidification. However, the production amount of fly ash is quite

huge. Even all storage capacities of established safe landfill plants for hazardous

wastes to dispose the newly-added fly ash will be easily filled up within one year.

Meanwhile, the investment cost of safe landfill plants for hazardous wastes is rather

high. No matter in respect of capacity or economy, sending solidified fly ash into the

safe landfill plants for hazardous wastes is impracticable.

655. At present, it’s a general approach to dispose fly ash via sending it into the MSW landfill plants, but this approach has many loopholes during the implementation

process. In one hand, the national laws and administrative regulations haven’t clarified the regular supervision subject, test frequency and time limitation of the fly ash chelate

that can be sent into the MSW landfill plants. Therefore, the corporates conduct such

test themselves instead of regular supervision and relevant government management

departments and wastes landfill plants responsible for receiving fly ash don’t effectively supervise the fly ash test report provided by the incineration plants on the condition of

lacking effective daily supervision and adopt the fly ash landfill’s examination and approval process while certain test indicators are missing. On the other, some heavy

metals are unstable and can hardly meet the landfill plants’ standards. Meanwhile, its solidification mainly relies on organic or inorganic chelate and the long-term

solidification effect is uncertain to some extent.

656. Construction Plan for the National Urban MSW’s Harmless Treatment Facilities during the 13th Five-year Plan (draft for comment) points out that to

accelerate the treatment facilities’ construction and reduce the raw wastes’ landfill, incineration treatment technology is preferred to reduce the landfill amount of raw

wastes and achieve raw wastes’ “zero” landfill. Wastes landfill plants are mainly used for landfilling incineration sediments and other emergency situations. It can be seen

that landfill can be an emergency approach for the treatment of fly ash in incineration

plants, though some regions are not qualified for landfill. Fly ash’s resources utilization is a beneficial supplementation of landfill that can dispose fly ash.

657. The volatile elements content in fly ash, such as chlorine, sulphur, potassium,

sodium, etc. Water-washing pre-treatment approach must be adopted before sending


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them to the cement kiln to remove volatile elements, especially chlorine. However,

such approach will surely generate water-washing wastes with great chloride content

and there are no stable, effective and economical treatment approaches currently. The

latest edition of National Catalogue of Hazardous Wastes (2016 Edition) was carried

out on August 1, 2016 and Exemption and Management List for Hazardous Wastes is

newly-added, which allows MSW landfill plants and cement plants to accept fly ash

without applying any business license for hazardous wastes. The exemption only

involves fly ash’s specific disposal processes except the transfer process and it also clarifies the exempt disposal processes: fly ash entering to MSW landfill plants must

satisfy the MSW landfill standards and satisfy the cement kiln co-processing standards

if it should be sent to the cement kiln. The exemption controls the direction of fly ash

and clearly stipulates the treatment approaches and standards, which further

constrains the environmental influence brought by fly ash. The admittance barrier of

pollution-controlling corporates is lowered and the treatment market is enlarged as well.

Corporates can make full use of current technologies to comprehensively utilize fly ash

to reduce its harm. However, relevant controlling standards should be carried out by

the government urgently.

658. However, the applicability of hazardous wastes’ centralized technical specifications consulted by sintered ceramsite technology is relatively broad currently

and hasn’t defined the type of applicable kilns, corresponding facilities requirements and operative techniques. Besides, the requirements towards pollutants discharging

indicators and products’ pollution control indicators are rather loose. Such situation

makes the production and management of current fly ash’s treatment and disposal corporates lack normative guidance and standard limitation; makes the MSW

incineration power plants lack the foundation on which it is based while appointing the

treatment and disposal as well as inspection and acceptance of fly ash; makes the

government’s environmental protection departments lack professional supervision and regulatory foundation targeted at the treatment and disposal of fly ash. Meanwhile, it

is also not conducive to the technology’s promotion and application.

659. Mitigation measures: enact and improve relevant policies and regulations;

strengthen the supervision of wastes incineration, establish particular regulatory

authorities, adopts periodic inspection and aperiodic inspections to strictly inspect the

wastes incineration power plants’ operation, inspection and supervision data after

they’re put into operation, disclose the regulatory results regularly to accept the public

supervision; improve the fly ash treatment techniques; guarantee the environment

protection and promotion, etc.


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660. In Japan, the fly ash is landfilled in control-type final disposal sites after

detoxification treatment. When the final disposal site is to be decommissioned, it has

to comply with Decommission Standards, which stipulate the use of site after the

closure. If the closure site is to be used for general purposes, notification of character

change has to be submitted to the authority. Generally municipalities in urban areas in

Japan, where it is difficult to procure land to construct a final disposal site, hand over

slag and fly ash to private disposal companies to dispose of by landfilling based on

contract. There were cases where such private businesses were not able to comply

the Landfilling Standards and caused groundwater contamination as a result of

inappropriate management. In such pollution cases, if the private subcontractor goes

bankrupt and has no financially capable of restoring to its original state, the National

Government takes measures to restore to it for the time being and imposes the

business contractor or local government to pay the equivalent cost afterwards.

9.3.2 The Environmental Impact of MSWI Fly Ash Storage / Treatment and

Disposal Process

9.3.2.1 Risk of Particle Escaping in Disposal Process

661. Fly ash particles are very small, containing a large amount of fine particles of

PM10 or even PM2.5. Fly ash in the co-processing or landfill disposal process, prone to

particle escape, resulting in other carcinogenic or non-carcinogenic risk to staff and

even surrounding residents due to eating, inhalation, skin contact.

662. The study found that non-carcinogenic risk of original ash is mainly caused by

Pb and dioxin, and the average of non-carcinogenic hazard caused by other heavy

metals is within acceptable range. Taking into account the synergistic additive effect

of each pollutant, the cumulative non-carcinogenic harm exceeds the acceptable level.

The carcinogenic risk of original ash is mainly caused by Cr and dioxin. The

carcinogenic risks of other heavy metals are acceptable. However, the cumulative

carcinogenic risk exceeds acceptable levels.

663. Compared to the original ash, a large number of soluble chlorine salts were

removed from the washed fly ash. However, a large number of pollutants such as

heavy metals and insoluble dioxins are enriched, resulting in higher non-carcinogenic

and carcinogenic risks of washed fly ash than the original ash.

664. The non-carcinogenic risk of washed fly ash decreased by about 50% on

average after dioxin detoxification treatment, the carcinogenic risk decreased by an


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average of about 30%. It can be seen that the main reason for the risk reduction is the

sharp drop in the concentration of dioxins after detoxification.

9.3.2.2 Leaching Risk of Fly Ash in Storage/Stacking Process

665. If the coverage is not timely during fly ash storage process, it is easy to cause

pollution of groundwater. In the process of the original ash stacking, single pollutants

were analyzed, and non-carcinogenic damage caused by Pb, Cd and Cr was greater.

non-carcinogenic harm caused by Zn, Cu, Ni, Hg is relatively small.

666. The washed fly ash in the storage process, the non-carcinogenic harm caused

by Pb, Cd and Cr is relatively great. Non-carcinogenic harm caused by Zn, Cu, Ni, Hg

is relatively small. After washing pretreatment, the non-carcinogenic harm caused by

heavy metals is reduced to some extent. After the fly ash was pretreated by washing,

the non-carcinogenic harm caused by groundwater under its storage scenario

decreased obviously, but it was still unacceptable.

667. In addition to the original ash, deposition leaching of washed fly ash, the

stabilized fly ash may also be stacked deposition leaching situation. Non-carcinogenic

hazards of stabilized fly ash with inorganic stabilizers during storage/stacking are

mainly caused by Pb and Cr. The cumulative non-carcinogenic hazards of inorganic

chelating agents to stabilize cured fly ash are far below acceptable levels. After the fly

ash has been cured with an inorganic stabilizer, its health risk due to groundwater

leaching is much lower than that of raw and washed ash, and the risk is acceptable.

Non-carcinogenic leaching by leaching and solidification of organic chelating agent

stabilized fly ash during storage/stacking is mainly caused by Pb and Cr. The

cumulative non-carcinogenicity of all contaminants is well below acceptable levels. The

cement-stabilized fly ash shows greater non-carcinogenicity caused by Pb and Cr

during leaching during storage/stacking. The cumulative non-carcinogenic hazard in

most samples exceeds acceptable levels

9.3.3 MSW Incineration Fly Ash Products’ Environmental Influence

668. Fly ash can be sent to the MSW landfill plants for landfilling after stabilization.

However, the stabilization mainly adopts organic or inorganic chelates, which has

slight effect upon the heavy metals’ uncertain long-term stability and the treatment of

organic pollutants such as dioxins.

669. Cement generated via cement kiln co-processing has certain environmental


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influence. The content of heavy metals with high toxicity such as lead, cadmium,

mercury, etc. in fly ash is two or three magnitude level high than that in cement raw

materials while co-processing can increase the heavy metals content in the cement;

most of heavy metals with high toxicity such as lead, cadmium, mercury, etc. generated

during the cement calcination process will be volatilised and enter to fuel gas, then be

captured to the kiln. After that, the kiln dust will be re-calcined back to the kiln or be

directly blended with cement clinkers to be part of the cement products, which

essentially dilutes heavy metals into the cement products; cement products have

certain longevity in the environment and will turn into construction wastes once their

service is up. Currently, plenty of heavy metals brought by fly ash’s co-processing will

become a heavy burden for the future construction wastes’ treatment and application

undoubtedly. The application of fly ash-asphalt concrete mixed products as pavement

materials, fly ash-cement concrete mixed products as pavement materials and fly ash

as admixture added soil as road base material are the three main directions of

application, and the risks posed by rainwater leaching leading to contaminants entering

the groundwater should be assessed.

670. Sintered ceramsite technology for fly ash meanwhile achieves the

harmlessness and quantity-reducing treatment of wastes incineration fly ash with

dioxins, etc. substances from the fly ash absolutely dissolved during the ceramsite’s high-temperature stage and volatile heavy metals volatilised into the fly ash for a

second time under the impact of chloride. Besides, involatile heavy metals will be

solidified and stabilized in the ceramsite’s mineral crystal lattice after high-temperature

sintering and finally generate ceramsite products with low heavy metals content and

leach solution amount, which improves the products’ long-term stability and

environmental friendliness. Such products can be high-quality raw materials that act

as subgrade materials, road brick aggregate and landfill plants’ covering soil.

671. There was a case of environment pollution where a private business was

commissioned by a local government to composting by mixing organics with

incineration ashes accepted from the local government, and they failed to store the

compost products appropriately and caused contamination of the surrounding

environment. In another case, a private company sold baked granules recycled from

fly ash as silt, and the products were used as soil amendment and backfill material,

afterwards the used sites were found to contain soil contaminated with hexavalent

chromium, which cost huge amount of money to restore to its original state.


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9.4 Expectations on the Economic Benefits of the Optimal

Practicable Technology’s Application

672. Fly ash’s safe disposal approaches include cement solidification, chemical agent solidification, acid solvent extraction and melting solidification, etc., while the

most desirable one adopted by environmental departments in developed countries

such as America, Germany and Japan is melting solidification. It’s because this technology can reduce over two thirds of ash residues and alleviate the burden of

landfill sites; besides, it can also recycle the valuable metals in the slags, dissolve

harmful substance such as dioxins. Therefore, the melting solidification technology

dealing with MSW incineration fly ash can dominate the treatment and disposal of fly

ash in the future.

9.4.1 Cost of Technical Application

8.4.1.1 Technology Cost for Fly Ash Disposal in China

673. In recent years, various corporates or units working on the treatment of solid

wastes introduce high-temperature melting or plasma technology for the vitrification of

solid wastes in succession, the environmental stability of whose products achieve

advanced international standards, with no organic pollutants and rather low heavy

metals leachability. The direct operation cost is about RMB 1000 yuan/ton and it greatly

reduces the fly ash’s landfill amount and solves the conflicts brought by shortage of

land resources. However, importing the whole set of equipment costs a lot - the single

set of equipment is about RMB 100 million yuan. The investment cost is relatively high.

But the domestic self-developed mini plasma melting equipment with a low investment

cost has been put into operation successfully. Currently, the research and

development on large-scale plasma melting equipment is underway as well.

1) Sintered Ceramsite Technology:

674. Viewing from construction of the demonstrative production line and operation

condition of Tianjin Yiming Environmental Technology Co., Ltd., the construction

expenses required for a project disposing 5000 tons’ wastes incineration fly ash annually to establish a sintered ceramite production line is about RMB 130 million yuan.

The production line of wastes incineration fly ash’s centralized amount-reducing

disposal mainly incudes solid wastes sintering machine system, fuel gas treatment


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system, second-level water-washing system and supplementary facilities. The direct

treatment expenses of each ton of wastes incineration fly ash is about RMB 800-1000

yuan and the treatment process doesn’t generate any obvious second pollution. Other cost also include the transportation cost of transporting the wastes incineration fly ash

to the plants (RMB 1 yuan/t·km).

2) Cement Kiln Co-processing:

675. Fly ash is co-disposed through the process from Beijing Jinyu Liulihe Cement

Plant with a total investment of about 110 million yuan, a multi -stage technology and

equipment system should be built, including countercurrent rinse, precipitation,

pressure steaming, separation, drying and dehydration, to reduce the content of

volatile elements (chlorine, sulfur, potassium and sodium, etc.) and heavy metals in fly

ash; first, the fly ash should be washed and purified to the acceptable level of cement

kiln so that it can be used as an alternative raw materials entering the kiln and turn into

mature material after calcination. For Beijing Jinyu Liulihe Cement Plant, the direct

incineration fly ash disposal expense is about RMB 1,400-1,700 yuan while the fly ash

in the plant has dry chlorine content of 22% with an annual disposal amount of 20,000

tons. The disposal cost is rather high and the Beijing Municipal Government therefore

subsidizes RMB 1,320 yuan for each ton of fly ash.

676. Sintered ceramsite technology can collect heavy metals and chloride together

in the secondary fly ash and such secondary fly ash can be landfilled. Compared with

direct landfill disposal, sintered ceramsite technology can effectively alleviate the

problems caused by insufficient landfill capacity and create beneficial condition for the

extraction of heavy metals. Though its comprehensive cost is higher than the cost of

landfill, such technology can achieve the amount-reducing and harmfulness as the

same time. While disposing fly ash with the cement kiln co-processing approach, part

of the raw materials can be replaced so as to reduce the discharge amount of CO2.

However pre-treatment before sending fly ash into the kiln should be conducted and

the technical application cost is relatively high while the whole technique can’t separate and recycle heavy metals and the products’ long-term stability and environmental

friendliness still wait to be evaluated.

9.4.1.2 Technology Cost for Fly Ash Disposal in Japan

677. Figure 8-3 shows the structure of fly ash disposal cost in Japan.


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Fig 9-3 Cost Structure for Fly Ash Disposal in Japan

678. The fly ash, which is low quality, small quantity, and dispersed, is very difficult

to recycle. As it would not be sold, the cost for treatment must be paid. As long as the

final disposal cost is around 20,000 yen per ton at local government facilities, the

recycling is difficult to be viable.

679. Shown below is a list of cost effective treatment methods, utilization ways and

recycling technologies:

Chelate Treatment + Final Disposal; 5,000 yen/t + Disposal Cost (10,000 yen to

20,000 yen/t)

Cement Solidification + Final Disposal; 3,000 yen/t + Disposal Cost (10,000 yen

to 20,000 yen /t)

Use as Cement Material + Transportation Cost; 40,000 yen to 50000 yen/ t +

Transportation Cost

Making Eco-Cement + Transportation Cost; 45,000 yen to 50000 yen/ t +

Transportation Cost

Reductive Melting Business + Transportation Cost; 40,000 yen / t +

Transportation Cost

Non-metal Recovery at Smelter + Transportation Cost; 60,000 yen / t +

Transportation Cost

Baking Business + Transportation Cost; 30,000 yen to 40,000/ t +


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Transportation Cost

Melting Treatment by Local Government; 60,000 yen / t

9.4.2 Analysis on Product Value and Market Demand

680. Melting solidification is an effective treatment technology for wastes

incineration fly ash. All the heavy metals’ leaching concentration of leach solution leached from disposed fly ash slags doesn’t exceed the standard limit of leach toxicity

identification and the slags doesn’t have any leach toxicity. Its material is compact and hard with certain intensity and the prerequisite for resources utilization. In accordance

with the human health risks’ assessing result, comparing the disposed fly ash slags

with the undisposed raw fly ash, its hazard is only 0.2% of that of raw fly ash, which

will not cause any potential threats to the environment or human body and can be used

for resources utilization as subgrade materials.

681. The high-temperature sintered sediments generated via sintered ceramsite

technology can be used as high-quality raw materials that act as subgrade materials,

road brick aggregate and landfill plants’ covering soil with a price (ceramsite) of about RMB 100 yuan/ m3. Such income can offset part of the treatment cost. Meanwhile, it

can save the wastes incineration fly ash’s landfill expenses of about RMB 500-600

yuan/ton. The treatment of fly ash differs from the production of other products. It aims

at the social and environmental benefits.

682. The cement production amount in 2015 is about 2.4 billion tons. Cement

occupies a huge market demand, which can promote the fly ash’s co -processing

amount. However, in actual production process, the fly ash adding quantity should be

controlled and the treatment standard should be strictly executed to guarantee the

cement products’ quality. At the same time, the potential environmental hazard caused by fly ash heavy metals in cement products can never be ignored.

683. In Japan, demand for recycled products derived from fly ash in the society is

discussed here.

Normal Cement: In cement plants equipped with water-washing pretreatment

facility, normal cement products complying with JIS are duly manufactured.

Therefore the demand is most promising.

Eco-Cement: As eco-cement has limited scope of utilization because of its

components, certain system should be elaborated to secure its demand. But

once a cement company establishes such a system, certain amount of


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demand can be expected.

Slag and Metal: As slag products are standardized as JIS, demand can be

large once quantity is ensured. To respond to such large demand, storage

facilities are essential.

Recovery of Zinc etc.: Demand does exist for recovered zinc at smelter of

mining companies. The more advantageous, however, is found in the

appropriate treatment of undesired salts.

TA-8963 PRC Final Report Chapter X

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CHAPTER 10 SUSTAINABLE MANAGEMENT

STANDARD AND POLICY SUGGESTIONS OF MSWI

FLY ASH IN CHINA

10.1 Standard Suggestions

684. As mentioned before, the establishment of technical pollution control

specifications during incineration fly ash’s whole-process management is in urgent

need currently, including the technical standards or specifications on the controlling of

pollution that generated during the incineration fly ash’s package, transportation, storage, disposal and resources regeneration process.

685. Currently, Technical Specification for Pollution Control on Municipal Solid

Waste Incineration is under formulation by the Ministry of Environmental Protection.

The project has been established but the subject hasn’t been initiated. As far as we know, the suggestion draft of this technical specification mainly contains the following

contents:

Technical requirements for detoxification and pollution control on pre-

treatment usually include the general requirements, technical requirements

for pollution control on solidification and stabilization pre-treatment, technical

requirements for pollution control on detoxification and pre-treatment of

dioxins, molding pre-treatment, etc.;

Technical requirements for pollution control on co-processing are composed

of general requirements, cement kiln co-processing, high-temperature

sintered co-processing, high-temperature melting co-processing, civil

engineering materials’ productive blending co-processing, etc.;

Technical requirements for pollution control on landfill disposal wastes

Pollution control and supervision on the treated and disposed products as

well as the disposal sites facilities

Administrative policies on the pollution control of the treatment and disposal

686. In the proposal draft of this technical specification, heavy metals content

standards of construction materials generated via the utilization of incineration fly ash

and discharge standards of air pollutants during the production process, as illustrated

in Table 9-1 and Table9-2 respectively.


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Table 10-1 Heavy Metals Quality Standards of Co-processing Outcomes (Product) (mg/L)

Elements Leaching Limits Total Quantity Limits

Cadmium 0.01 150

Plumbum 0.01 150

Hexavalent Chromium 0.05 250

Arsenic 0.01 150

Total Hydrargyrum 0.0005 15

Selenium 0.01 150

Zinc 100 100

Nickel 0.5 40

Copper 40 35

Table 10-2 Standards for Air Pollution Control

No. Pollutants

Limits of Diverse Incineration Capacity

≤300 kg/h 300-2500

kg/h ≥2500 kg/h

1 Particles(mg/m3) 100 80 65

2 Carbon Monoxide(mg/m3) 100 80 80

3 Sulfur Dioxide(mg/m3) 400 300 200

4 Nitrogen Oxides(mg/m3) 500

5

Hydrogen Chloride(mg/m3) 10

6 Hydrogen Fluoride (mg/m3) 1

7

Mercury and its Compounds (calculated with Hg) (mg/m3)

0.05

8

Cadmium and its Compounds (calculated with Cd) (mg/m3)

0.1

9

Thallium, Lead, Arsenic and its Compounds (calculated with

Tl+Pb+As) (mg/m3) 1

10

Beryllium, Chromium, Tin, Antimony, Copper, Manganese, Nickel,

Vanadium and its compounds (calculated with

Be+Cr+Sn+Sb+Cu+Co+Mn+Ni+V)

0.5

11 Dioxins (ng TEQ/m3) 0.1

687. Compared with the above-mentioned results, the proposal draft of this

technical specification doesn’t cover any technical contents related to the pollution control of incineration fly ash’s package, transportation, storage. Therefore, the Ministry of Environmental Protection should be suggested to supplement these

contents in the follow-up work of establishing this technical specification. Meanwhile,

further demonstration on the involved various treatment, disposal and regeneration


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technologies should be considered about as well to guarantee the incineration fly ash’s proper disposal and harmless management.

688. Refer to Japan experiences to improve regulations:

Control Procedure for Fly Ash: It should be reviewed corresponding to development

of treatment technologies. Monitoring of hazardous- substance- contained material is

necessary. Legal framework should be improved for a control system on hazardous

materials based on Basel Convention. Legal provision such as Specially Controlled

Municipal Waste in Japan may be needed.

Needed Standard for Detoxification: The four methods established in Japan can be

referenced. The chemical insolubilization is not sufficient because there is no Standard

on chemical behavior in the environment. Chemical Standards should be established

in consistent with standards on final disposal site and on decommission.

Establishing Recycling Standard for small quantity and individual use is difficult.

There have been cases where a business operator accepts waste in exchange for

cash pretending to recycle it, but actually dumps it illegally or misuses it. It is necessary

that local government have responsibility to confirm appropriateness of the handover

of waste to a business operator in exchange with money.

Manifest System: It is necessary to monitor operation of private businesses that try

to dispose of waste inappropriately pretending that they recycle it. Manifest system

may be needed.

10.2 Technical and Environmental Standards System of MSW


689. Vitrification on solid wastes has been widely applied in developed countries

such as European countries, America and Japan, etc. Toxic materials such as heavy

metals are solidified into the compact three-dimensional glassy structure with a high-

level stability, uneasy to be discharged and the environmental risks is relatively low.

Therefore, such technology acts as the general wastes treatment approach in

European Union, Japan, America, etc. and has improved technical specification and

identification system. The catalogue of hazardous wastes proposed by European

Union clarifies that the glassy slags generated via the disposal of hazardous wastes

are generally solid wastes (Solid Wastes Code: 19 04 01). In 1992, the Environmental


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Protection Agency (EPA) carried out Technical Manual on the Vitrification Engineering

of Hazardous Wastes to guide and encourage the application and promotion of

vitrification of hazardous wastes.

690. At present, many corporates have applied high-temperature melting, plasma

and other approaches to conduct the harmless treatment on solid wastes in China. The

environmental stability of the products produced by such technologies has reached an

international advanced level - with no organic pollutants, low heavy metals leachability

and beneficial social and environmental benefits.

691. National Catalogue of Hazardous Wastes published by the Ministry of

Environmental Protection in 2008 also clearly stipulates that for slags produced by

solid wastes’ incineration, glassy substances disposed via plasma and high-

temperature melting, etc. can’t be classified into hazardous wastes, which is consistent with the policies of developed countries such as European Union, Japan and America,

etc. To explain the above-mentioned terms of National Catalogue of Hazardous

Wastes from a technical prospective, it clarifies the definition of glassy products,

specifies the vitrification treatment technology of solid wastes and promotes the

normalization of solid wastes’ treatment and disposal. Proposed by industrial experts and part of the corporates on the basis of testing and analysing the phase, component,

leaching toxicity of solid wastes’ vitrification products, the National Technical Committee for the Products’ Recycling and Utilization Basis and the Management’s Standardization plans to stipulate basic requirements of solid wastes’ vitrification products and the evaluating indicators and approaches based on the relevant

standards or provisions of developed countries.

692. The content of this standard totally complies with the laws and regulations of

national environment protection work. Meanwhile, this standard also clearly defines

the glassy substances listed in National Catalogue of Hazardous Wastes generated

via plasma, high-temperature melting, etc. from the technical prospective, which

positively supports the vitrification treatment of solid wastes, especially hazardous

wastes and will impressively promote the normalization and standardization of the solid

wastes’ treatment and disposal.

693. Relevant technical and environmental standards are illustrated as follow:

1) Technical indicators for the landfill of wastes incineration fly ash

Fly ash to be sent to the incineration plants should satisfy the requirements

of Pollution Control Standards of MSW Landfill Plants (GB16889-2018).


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2) Technical indicators for cement kiln co-processing fly ash:

❖ Cement kiln co-processing must satisfy the requirements of Solid Wastes

Pollution Control Standards for Cement Kiln Co-processing (GB 30485-

2013).

❖ The leachable heavy metals content of the products generated via

cement kiln co-processing can meet the requirements proposed by

Technical Specifications for the Co-processing of Solid Waste in Cement

Kilns (GB 30760-2014).

❖ Cement kiln co-processing system complies with the technical

requirements of Environmental Protection Technical Specification for Co-

processing of Solid Waste in Cement Kilns (HJ662-2013).

3) Technical indicators for the technical system of wastes incineration fly

ash’s centralized amount-reducing disposal

❖ Cement kiln incineration system complies with the technical requirements

of Pollution Control Standards for Hazardous Wastes Incineration

(GB18484-2014).

❖ Fuel gas advanced purification system complies with the requirements

proposed by Engineering and Construction Technical Specifications for

the Centralized Incineration Disposal of Hazardous Wastes (HJ /T 176-

2005).

❖ Other supplementary equipment can abide by the stipulations of Solid

Wastes Environmental Protection Technical Specifications for Cement

Kiln Co-processing (HJ/T 662-2013).

4) Technical indicators for fly ash ceramsite (high-temperature incineration

sediments)

❖ Fly ash ceramsite can be directly used as landfill plants’ covering soil and it abides by the requirements of Geotechnical Engineering Technical

Specifications for MSW Sanitary Landfill Plants (CJJ 176-2012) and

Technical Specifications for MSW Sanitary Landfill Technology (CJJ17-

2004);

❖ Water-washing and desalinized fly ash ceramsite can meet the

requirements of Technical Specifications for Construction of Highway

Subgrades (JTG F10-2006);

❖ The environmental pollution effect of dioxins from fly ash ceramsite can

meet the secondary standard requirements on residential land proposed


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by Environmental Quality Standard for Soil (draft for comment) (GB

15618-2008);

❖ The leachable heavy metals content of fly ash ceramsite can meet the

requirements of Solid Wastes Technical Specifications for Cement Kiln

Co-processing (GB 30760-2014) (Note: this specification clarifies the

leaching toxicity limits of heavy metals from cement products. Grinding

fly ash ceramsite into powders like cement particles can easily meet the

standards of executing this requirement. Grinding the fly ash ceramsite

into powders for the leaching toxicity test of heavy metals can better

illustrate the ceramsite products’ ecological and environmental safety under harsh circumstances such as mechanical crush, natural

weathering, acid rain attack, etc.

5) Fuel Gas Discharge Standards during the Fly Ash’s High-temperature

Incineration

694. Fuel gas generated from the high-temperature incineration process can meet

the requirements of Pollution Control Standards of Hazardous Wastes Incineration (GB

18484-2001) and Solid Wastes Pollution Control Standards for Cement Kiln Co-

processing (GB 30485-2013) after purification.

10.2.1 Standard Draft for MSW Incineration Fly Ash’s Vitrification

1. Scope

This standard stipulates solid wastes vitrification’s terms and definition, basic

requirements of vitrification products as well as its assessment indicators and

approaches, etc.

This standard is applicable to the products’ definition and environmental stability

judgement after the vitrification of general solid wastes and hazardous wastes, but not

applicable to the treatment of radioactive solid wastes.

2. Normative References

The following references are indispensable to the application of this file. For any

references with market-out dates, the only marked-out version is applicable to this file

while the latest version of references with no dates (including all modified lists) is

applicable to this file.

GB 5085 Methods for Identifying and Distinguishing Hazardous Wastes

GB 5086 Leach Approach of Solid Wastes Leach Toxicity

GB 18597 Pollution Control Standards for the Storage of Hazardous Wastes


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GB/T 30904 Analysis on Inorganic Chemical Products’ Crystal Structure - X-ray

Diffraction Method

HJ/T 298 Technical Specifications for the Identification of Hazardous Wastes

HJ 2025 Technical Specifications for the Collection, Storage and Transportation

of Hazardous Wastes

3. Terms and Definitions

The following terms and definitions is applicable to this file.

3.1 Solid Wastes

Solid wastes refer to solidity and semi-solidity generated during the production, life

and other activities but losing its original utilization value or those maintaining the

utilization value but were abandoned or given up as well as gaseous materials,

substances contained in the container, and materials and substances that are listed

into solid wastes management list by the laws and administrative regulations.

3.2 Vitrification

Vitrification is a solid wastes treatment approach that blends solid wastes with

solvent and auxiliary that are easy to form vitrification phase to form homogeneous

melting substances under high temperature and amorphous glassy substances after

cooling down will help with the stabilization of poisonous and harmful substances such

as heavy metals.

3.3 Product of Vitrification

Amorphous and glassy residues generated via the vitrification of solid wastes

4. Technical Requirements of Vitrification Products

4.1 Solid wastes’ vitrification products should satisfy the following indicators.

The mass fraction of glassy components should remain no less than 99%.

The SiO2 content of solid wastes’ vitrification products should be no less than 20%.

Grind solid wastes’ vitrification products and sock them in the solution with a pH

value of 3, 7 and 11 respectively. The leaching concentration of the following elements

shouldn’t exceed the requirements of Table 9-3.

Mechanical properties: vitrification products used as construction materials should

occupy certain compressive strength and Rockwell hardness.

Table 10-3 Leaching Toxicity Limits Requirements of Solid Wastes’ Vitrification Products

Elements Leaching Toxicity Limits (mg/L) As 0.06 Ba 4

Cd 0.02 Cr 0.1 Cu 0.6


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5. Test Approaches

The proportion of glassy components should be tested in accordance with the

approaches stipulated in GB/T 30904.

The content fraction of Si、Al、Ca adopts the test approach of inductive coupling

plasma atomic emission spectroscopy.

Solid wastes’ vitrification products should be grinded with high strength and soaked

in the solution with a pH value of 3, 7 and 11. The leaching toxicity should be tested in

accordance with the stipulated approach in GB 5086.

The Rockwell hardness of solid wastes’ vitrification products should be executed in

terms of JIS Z2245-2005

10.2.2 Technical Specifications for Wastes Incineration Fly Ash’s Safe

Disposal and Technical Specifications for MSW Incineration Fly Ash’s

Stability

695. On June 18, 2014, the project opening discussion conference for Technical

Specifications for Wastes Incineration Fly Ash’s Safe Disposal composed by the Ministry of Environmental Protection under the charge of the team of Professor Qian

Guangren in School of Environmental and Chemical of Shanghai University, convened

by the Department of Science and Technology of the National Ministry of

Environmental Protection in the main campus of Shanghai University. The composing

of this technical specification is not limited within specific disposal technology or

facilities and primarily standardizes the operation technology, pollutants discharge

indicators, disposed products’ properties during the wastes incineration fly ash’s overall disposal process to encourage local governments to disposal the wastes

incineration fly ash within its region in the light of local conditions and promote the rapid

progress of wastes incineration fly ash’s disposal technology. Everything required is that the relevant indicators meet the technical specifications. On September 25, 2016,

a new symposium was convened by the Chinese Research Academy of Environmental

Hg 0.002 Mn 0.2 Ni 0.12 Pb 0.15

Sb 0.1 Se 0.04 Zn 1.2 Cl 450 F 2.5 SO4 1500 PO4 0.3


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Sciences to discuss the technical highlights of this technical specification.

696. “Comprehensive Environment Management Project of MSW in China” is a global environmental fund developed via the cooperation between the Foreign

Economic Cooperation Center of the Ministry of Environmental Protection and the

World Bank. They also formulated Technical Specifications for MSW Incineration Fly

Ash’s Stability in July, 2016 for the engineering design, construction and operation of

MSW incineration fly ash’s stabilization to reduce the leaching dioxins amount in the environment caused by MSW incineration fly ash.

10.3 Policy and Management Recommendations

697. Strengthen the legislation at different levels and introduce adaptable guidance

documents; keep track of social development and technological updates in a timely

manner and speed up the formulation and improvement of relevant standards so as to

guide relevant departments in all regions to promote the disposal and monitoring of fly

ash. The regulatory mechanism, technical guidance and laws and regulations on the

utilization of incineration fly ash resources should also be established and improved so

that resource-based utilization can be followed.

10.3.1 Recent Policy Recommendations

10.3.1.1 Define the properties of MSWI Fly Ash and Confirm the Principal Responsible for MSWI Fly Ash Management

698. According to the definition of "Law of the People's Republic of China on the

Prevention and Control of Environmental Pollution by Solid Waste", household waste

incineration fly ash should belong to the category of "household waste". According to

this law, the main body responsible for the management of household waste is the

"competent environmental administrative department of the local people's government

at or above the county level, whose responsibility is "to organize the cleaning,

collection, transportation and disposal of municipal solid waste." However, in actual

work, the administrative objects of environmental sanitation administration often do not

include MSWI fly ash, but are borne by MSWI facility operators. This is also one of the

fundamental reasons for the difficulty in handling MSWI fly ash.

699. Therefore, it is necessary to clarify the attribute of "municipal solid waste

incineration fly ash" through the explanation of "Law on the Prevention and Control of

Solid Waste Pollution" and appropriate policies and regulations documents so as to


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clarify the liability main body of MSWI fly ash management. Which laid the basic policy

foundation for the completely solution of fly ash pollution.

10.3.1.2 Development of MSWI Fly Ash Pollution Control Technology Policy, Clear Technical Disposal Route Prioritization Order of MSWI Fly Ash

700. China's "Law on the Prevention and Control of Environmental Pollution by

Solid Wastes" does not specify the order of prioritization of technologies for prevention

and control of solid wastes encouraged by the state, which is troublesome to the

management of various types of solid wastes including solid waste incineration fly ash.

Therefore, it is urgent to formulate a " pollution control technology route for MSWI fly

ash pollution", in which the technical priority order of pollution control of MSWI fly ash

should be followed: priority is given to MSWI technology with small amount of

incineration fly ash; MSWI fly ash that has been produced should be used as much as

possible to meet the requirements of the national standard for the production of

construction materials. For unavailable MSWI fly ash, as far as possible in accordance

with the requirements of the "Municipal Solid Waste Landfill Pollution Control

Standards" for disposal.

10.3.1.3 Incineration Fly Ash Transportation and Resource Regeneration Exemption

701. Currently, technology for landfill disposal and co-processing in cement kiln of

incineration fly ash are complete, and corresponding exemption management

authorization has been obtained. Resource regeneration technology other than

technology for transportation of fly ash and production of cement using fly ash,

however, are under certain control or technical restriction. Therefore, it is suggested to

apply for exemption authorization of MSW incineration fly ash transportation and

resource regeneration from the Ministry of Environmental Protection while developing

above-mentioned Technical Specification for the Prevention and Control of Pollution

by Municipal Solid Waste Fly Ash based on corresponding researches.

10.3.2 Future Policy Recommendations

702. Innocent management of incineration fly ash should be carried out under the

framework system of solid waste management. But, the current system of solid waste

management in China is not so complete, so it is difficult to improve the innocent

management and technical level of incineration fly ash. It is necessary, therefore, to

revise the Law of the People’s Republic of China on the Prevention and Control of


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Pollution by Solid Waste so as to solve existing problems and improve solid waste

management system in China. In view of problems of innocent management of

incineration fly ash, the following contents of the Law of the People’s Republic of China on the Prevention and Control of Pollution by Solid Waste are recommended to be

amended.

(1) Specifying the management scope of MSW and confirming MSW properties of fly

ash.

As mentioned above, the definition of MSW in China varies largely from waste types

under actual management, so it is impossible to make sure whether incineration fly

ash belongs to MSW or not, and there is no specific basis for confirming the subject of

liability of innocent management of incineration fly ash.

(2) Establishing a solid waste system that "any entity or individual generating the solid

waste should be responsible for it" so as to confirm the subject of liability of innocent

management of incineration fly ash.

According to the Law of the People’s Republic of China on the Prevention and Control of Pollution by Solid Waste, for the prevention and control of environmental pollution

by solid waste, the State implements the principle that any entity or individual causing

the pollution should be responsible for it. The manufacturers, sellers, importers and

users should be responsible for the prevention and control of solid waste pollution

produced thereby". Based on this regulation, it is impossible to confirm who the polluter

of solid waste is or who should be responsible for it. Generally, innocent management

of incineration fly ash is undertaken by MSW incineration plants all over different

regions, because the subject of liability for such innocent management has not been

specified. In fact, however, MSW incineration plants are incompetent to conduct

effective innocent management of incineration fly ash, because MSW incineration

market is defective in its order and MSW incineration cost is generally low.

A practice internationally accepted is that any entity or individual generating the solid

waste should be mainly responsible for "cradle-to-grave" whole-process innocent

management of the solid waste. Since incineration fly ash is the residue of MSW

disposal, so incineration fly ash should be managed as MSW. MSW is generated by

urban and rural residents (taxpayers), so urban and rural administrators (city

administrators corresponding to cities) should assume this responsibility for urban and

rural residents. Although the Law of the People’s Republic of China on the Prevention and Control of Pollution by Solid Waste stipulates that "the people's governments at or


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above the county level should plan, as a whole, to build facilities for collecting,

transporting and treating urban-rural solid waste", but firstly the Law has not specified

"MSW properties" of the incineration fly ash, and secondly the Law has not declared

who is the subject of liability for construction and operation of facilities for collecting,

transporting and treating MSW (including incineration fly ash).

(3) Setting a national priority sequence (technical route) for choice of solid waste

management technology, explicating basic principles that should be followed to choose

disposal technology of incineration fly ash.

Setting the national priority sequence (technical route) for choice of solid waste

management technology in the Law of the People’s Republic of China on the Prevention and Control of Pollution by Solid Waste that is " avoiding or reducing, in the

first place, generation of solid waste or lowering content of harmful substances in it;

secondly, trying to use residual value (original value in use) of the solid waste; thirdly,

extracting and using desirable substances in the solid waste, fourthly, trying to use

energy of the solid waste or producing outcomes (products) generating energy, and

finally properly disposed of".

703. If such principle is established, development trend of fly ash innocent

management technology will be identified when choosing incineration fly ash disposal

and treatment technology and developing management policies for national

incineration fly ash technology.

10.3.3 Management Framework Recommendations

704. Incineration fly ash is hazardous waste, resulting from the incineration of

domestic waste. The administrative and technical management agencies of fly ash

should be the administrative department of environmental sanitation of cities (the

environmental sanitation administration or municipal administration of city

governments) and the administrative department of environmental protection (City

Government Environmental Protection Agency).

(1) Competent Administrative Departments of Environmental Health

If incineration fly ash is specified as MSW, then urban governments should bear the

responsibility of incineration fly ash innocent management. The Law of the People’s Republic of China on the Prevention and Control of Pollution by Solid Waste stipulates

that " the people's governments at or above the county level should plan, as a whole,


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to build facilities for collecting, transporting and treating urban-rural solid waste";

"competent administrative departments of environmental health of the people's

governments at or above the county level should organize to clear, collect, transport

and treat MSW and may, by the way of bidding, choose qualified entities to engage in

the clearing, collection, transport and treatment of urban consumer waste." Therefore,

competent administrative departments of environmental health should be responsible

for construction and operation facilities for collecting, transporting, storing, disposing

and using incineration fly ash. According to relevant laws and specific situations of

different regions, competent administrative departments of environmental health can

conduct such work voluntarily or entrust a third party which is capable to engage in

businesses of this area. Specific management modes should be adjusted according to

conditions in terms of locality and time, and imposing uniformity in all cases must be

avoided.

(2) Competent Administrative Departments of Environmental Protection

National competent administrative departments of environmental protection should

formulate policy and regulatory documents like control standards, technical

specifications and technical policies and management regulations for pollution by

incineration fly ash; local competent administrative departments of environmental

protection should conduct effective and whole-process management of environmental

protection against collection, transportation, storage, disposal and utilization of

incineration fly ash on the basis of those regulations and other relevant laws and

regulations, including examination and approval of environmental protection

administrative licensing, filing and approval of duplicate forms for transfer as well as

site supervision and management against facilities and organizations for collection,

transportation, storage, disposal and utilization of incineration fly ash.

10.3.4 Recommendations for Regulatory System and Framework

705. Improve the treatment facilities and regulatory system. The environmental

protection department should incorporate the treatment and disposal of incineration fly

ash into the regulatory system of incineration facilities, establish a true and exhaustive

archive record, and register the fly ash disposal process. Strict implementation of

hazardous waste production units to declare the registration, hazardous waste permit

management, hazardous waste transfer single management system, a clear number

of incineration fly ash, flow, storage, and disposal methods and so on should be

clarified. Provinces (autonomous regions) should establish centralized treatment and

disposal center and remote regulatory center, managed by the environmental


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departments via periodic inspection and random sampling. The distinction within a

province (autonomous region) is relatively small, which makes the overall planning

much more convenient; therefore, one or two centralized treatment and disposal center

for hazardous wastes should be built in the province (autonomous region) to dispose

the incineration fly ash all together. The facilities scale effect can effectively reduce the

cost and save the fly ash’s transportation expenses. So far, several provinces have built centralized treatment and disposal centers for hazardous wastes, which can also

supervise the incineration plants’ operation remotely.

706. For the fly ash generated out of Waste Incineration Plant in Japan, four

detoxification methods are provided. And the effect must be confirmed in the elution

test. The test must be conducted at least once a year. In Japan, there have been some

cases reporting lead elution amount exceeds the standard. In such a case of excess

standard, it is necessary to add more volume of chelate agent and check the effect by

conducting more frequent confirmations.

10.3.5 Implementation Plan and Safeguarding Measures

707. Final disposal by landfilling after detoxifying treatment is most economical. But

if the location of final disposal site is very far, it may be better to recycle it even if the

cost is a little high. Also recommended is by making use of smelting process of

already established metal smelting industry, cement industry, and electric furnace

industry, they are recycled into materials like sand and stone, or zinc and lead are

recovered, and afterwards alkali salts are washed and discharged into the sea. Eco-

cement manufacturing technology is recommended as even fly ash containing much

salts can be utilized for the raw materials.

708. Detoxification treatment by using chelate agent in itself is effective. When

future decommission of final disposal site is foreseen, however, the chemical agent to

be used should be carefully examined, as the leachate should include decomposition

substance of chelate agent. In Japan, there is no Standard concerning the use of

chelate agent. It would be desirable to set such Standard.

10.4 Conclusion

709. Fly ash is an end product of concentrated and enriched toxic pollutants. The

more toxic substances in fly ash, the less toxic material released into the environment

is. Therefore, pollution control goal is finally achieved only if fly ash is disposed of


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properly.

710. At present, disposal modes of MSW incineration fly ash in China are mainly:

disposal at the hazardous waste landfill site after solidification treatment, disposal at

the MSW landfill site after stabilization treatment, co-processing in cement kiln and

sintered caramite, etc. Other disposal technology or resources utilization technology

are still at the laboratory research stage, so in order to achieve sustainable

management of fly ash, it is recommended to take acting up to environmental ethics

and regional differences as the basic principle, to carry out more disposal and

resources utilization technology, such as sintering and melting technology, extraction

technology of heavy metals, etc.

711. Recently, in China, there is no sound and perfect system of technical

standards for fly ash treatment and disposal technology, so it is suggested to develop

technical specifications for whole-process management against control of pollution

caused by incineration fly ash, including technical standards or technical specifications

for packaging, transportation, storage, disposal and resource regeneration processes

of incineration fly ash. A specific example is the technical specification for fly ash

sintered caramite technology.

712. It is suggested to apply for exemption authorization of MSW incineration fly

ash transportation and resource regeneration from the Ministry of Environmental

Protection while developing the Technical Specification for the Prevention and Control

of Pollution by Municipal Solid Waste Fly Ash based on corresponding researches.

713. In view of the innocent management problems of incineration fly ash, the

following amendment of the Law of the People’s Republic of China on the Prevention and Control of Pollution by Solid Waste is recommended: specifying the management

scope of MSW, and confirming MSW properties of the incineration fly ash; establishing

the solid waste system that “any entity or individual generating the solid waste should

be responsible for it” so as to confirm the subject of liability of innocent management

of incineration fly ash.

714. It is recommended that administrative and technical management

organizations of incineration fly ash should be urban competent administrative

departments of environmental health and environmental protection.

TA-8963 PRC Final Report Chapter XI

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CHAPTER11 DEVELOPMENT OF MSWIP DATABASE

AND SERVICE PLATFORM

715. With regard to the safe disposal of waste incineration fly ash in China, the

presentation and dissemination of information so far have been undertaken exclusively

by businesses and there has been no relatively professional industry platform available

for public use. The construction and implementation of the present project – the

industry platform of the Tianjin Safe Disposal of Municipal Solid Waste Incineration Fly

Ash Technology Engineering Center – have been made possible through the

leadership of Tianjin Yiming Environment and the support of the Asian Infrastructure

Investment Bank.

716. At present, information about the safe disposal of waste incineration fly safety

that can be found on the domestic network platform is limited to publicity information

on some corporate websites and personal documents. The industry platform of the

“Tianjin Safe Disposal of Municipal Solid Waste Incineration Fly Ash Technology

Engineering Center” will be a specialized, professional and non-profit industry platform

and will be of great help in organizing and searching information.

11.1 Network Platform Environment Both at Home and Abroad

1) The Status of Foreign Network Platform

At present, for domestic solid waste incineration fly ash technology, advanced foreign

technologies are mainly distributed in some regions of Europe, the United States and

Japan, and their network platform information is also relatively rich; many information

are worthy of reference and reference.

2) The Status of Domestic Network Platform

At present, this piece of information on the safe handling of incineration fly ash is

displayed and advertised in the domestic enterprises for the nature of information.

There is not a relatively professional industrial platform for you to browse and review.

Most of the documents are for reference or reproduced from abroad Literature. This

piece of domestic network platform is in urgent need of a wide range of professionals

to participate in and maintenance to establish an industry-specific platform for you to

better understand and pay attention to the harm of MSW incineration and disposal

methods.


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3) Platform Construction Background and Purpose

Based on the above factors, with the full support from the AIIB, led by Yat Ming

Environmental in Tianjin, the successful construction and implementation of the

industrial platform for the existing project “Safety Engineering Technology Center for

Solid Waste Incineration Fly Ash” was completed. Therefore, after the construction of

the industrial platform of “Solid Waste Incineration Fly Ash Safety Disposal Technology

Engineering Center” is completed, there will be a specialized, professional and non-

profit industry platform, which for future information collation and information inquiry

Will have a great help.

11.2 Network Platform Foundation Information Description

11.2.1 Project Implementation Progress Statement

The initial construction of the project is basically completed. The middle phase of the

project has been completed. The project can be accessed through the independent

temporary domain name www.nswaitertest.com; pages display completely without any

bugs; page information can be added and maintained in the background. The functions

are perfect as shown a functional test. For each functional section, information can be

added, deleted or modified in the background. All the functional requirements

discussed regarding the presentation of the functions of the project platform are correct.

There is a relative lack of information and more information is needed to improve the

platform. Project presentation has been improved. Some details and specific pages

need to be adjusted. Meanwhile, materials related to the platform need to be submitted

for recordation, so that the platform can be used through the official domain name as

soon as page modification is complete.

11.2.2 Functional Requirements Project Implementation

Platform navigation: About Us – News – Notices and Announcements – Scientific

and Technological Achievements – Policies and Regulations – Document

Download – Contact Us.

Functional description: The main system function of the platform is the information

presentation system, through which individual pages and the news presentation

system are managed;

Technical description: The platform uses the PHP language and MySQL database


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management functions, making it more extensible.

Host description: At present, the platform uses a virtual host. The hosting space is

1G. Enough space resources are retained for data storage, so that the capacity of

the virtual host can be expanded at any time to accommodate more information

resources.

Database maintenance: For platform applications and database information, the

server itself has a monthly backup function. We will check data and application

platforms from time to time to ensure the normal operation and management of

platform applications.

11.2.3 Project Implementation Basic Safety Instructions

Database Security

The security of the network database mainly refers to protecting the database against

data leakage, changes or damage caused by illegal use. The most common solutions

for the above-mentioned risks associated with the network database include the

following:

11.2.3.1 Network Database Backup and Recovery

Data backup and recovery is an important technology for the safe operation of the

database system. Database system failures are inevitable, such as hacking, virus

infection and other operating system failures. System failures will inevitably result in

damage to important data. The space we recommend is a virtual host. The space is

1G in size, suitable for the Windows or Linux platform. Languages like

ASP/ASP.NET/PHP will be supported later. The database used is a MySQL database,

which has the following security features to give us a better and healthier network

application environment:

Account security: Account is the most simple security measure for MySQL. Each

account consists of a user name, a password and a location (usually the server name,

IP address or wildcard character).Different login paths lead to different login results;

MySQL’s user structure is user name/password/location, which does not include the

database name. User permissions are edited by other means, for example:

The following two commands set SELECT user permissions for database1 and

database2.


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GRANT SELECT ON database1.* to ‘abc’@’server1’ IDENTIFIED BY ‘password1’; GRANT SELECT ON database2.* to ‘abc’@’server1’ IDENTIFIED BY ‘password2’;

The first command sets the password1 user abc uses when connecting to database

database1.

The first command sets the password2 user abc uses when connecting to database

database2.

Therefore, the passwords user abc uses to connect to database1 and database2 are

not the same.

The above settings are very useful. If you just give a user limited access to a database

and no access to other databases, you can set different passwords for the same user

If you do not do so, there will be trouble when the user finds that the user name can

be used to access other databases.

At present, we only grant customers permissions to modify direct information of the

database. Permissions to modify other data tables of the database are used to

guarantee the relative security of the database and not available to customers.

Generally, you can use three different types of security checks in the MySQL database:

(1) Login Authentication

The most commonly used username and password authentication. If you enter the

correct username and password, then authentication succeeds.

(2) Authorization

After a successful login, you will be required to set the user’s specific permissions,

such as whether the user can delete tables in the database.

(3) Access Control

This security type is more specific. It is about what kind of operations the user can

perform on data tables, such as whether the user can edit the database, whether the

user can query data, and so on.

Access control is made up of some privileges which relate to the use and operation of


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data in MySQL. They are all Boolean types, either Permit or Deny. The following is a

list of these privileges:

• SELECT

SELECT is to set whether the user can use SELECT to query data. If a user does not have this privilege, then he can only execute a few simple SELECT commands, such as computational expression (SELECT1+2), date conversion (SELECT Unix_TIMESTAMP (NOW ())),etc. • INSERT

• UPDATE

• INDEX

INDEX determines whether the user can set indexes in tables. If a user does not have this privilege, then he cannot set indexes in tables.

ALTER

• CREATE

• GRANT

If a user has the GRANT privilege, then he can grant his own privileges to other users. In other words, the user can share his privileges with other users. • REFERENCES

With the REFERENCES privilege, a user can use one field in another table as a foreign key constraint to a table.

In addition to the above privileges, MySQL has some privileges that allow operating on the entire MySQL. • Reload

This privilege allows the user to execute various FLUSH commands, such as FLUSH TABLES, FLUSH STATUS, etc. • Shutdown

This privilege allows the user to close MySQL

• Process

With this privilege, a user can execute the SHOW PROCESSLIST and KILL commands. These commands can be used to view the MySQL process. You can view the details of SQL execution in this way. • File

This privilege determines whether the user can execute the LOAD DATA INFILE command. Caution should be exercised when granting a user this privilege, because users who have this privilege can load any file into a table, which is very dangerous to MySQL. • Super This privilege allows the user to terminate any queries (these queries may not be performed by the user). The above privileges are very dangerous and hackers often take advantage of these loopholes, so extra caution should be exercised when granting a user this privilege. The MySQL database shall be adequately protected to ensure that data in the MySQL database is absolutely safe.


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11.2.3.2 User Authentication and Privilege Control

11 User authentication is the first line of defense for the database system. The

primary function of the identity authentication system is to prevent invalid users from

registering to the database to perform illegal access operations and malicious

operations on the database by verifying the user name and password. User privilege

control is to grant certain privileges to the user while limiting his access to the database

and grant the user privileges to perform access operations on database entities while

preventing the user from accessing unauthorized data.

11.2.3.3 Audit Trail and Intrusion Detection

12 Audit trail and intrusion detection is mainly used for departments with high security

requirements and is the last line of defense for the database system. User identity

authentication and privilege control is the most widely used database security system,

but security vulnerabilities and the problem of valid users abusing their privileges exist

in all systems.

11.3 Instructions of Network Platform Front Shows

11.3.1 Instructions of Network Platform Front Designs

11.3.1.1 Platform Navigation

Center Profile – News – Notice – Technology Achievements – Policies and Regulations

– Documents Download – Contact Us

11.3.1.2 Design Concept

For the domestic professional and industrial portal site construction, the main idea is

to design the information to allow users to query and attention in the first time there is

a convenient operation process, through the home page design, making some

important, such as notice Announcements, the latest scientific research, the latest

policies and regulations and so on, information can be displayed on the first page for

the user to understand, with the navigation design, allowing users to find the

information you want to know the first time.


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11.3.2 Web Platform Front Page Description

The front page mainly consists of three kinds of page forms:

(4) two-screen page design

Home page using two-screen design style, some important elements such as

membership login, notice and policies and regulations, will present a comprehensive

display.

(5) single page design

For the “Introduction to the Center Introduction” and “Contacts” above, both of the page

impressions belong to the one page impressions.

(6) news show

“Dynamic work”, “notice”, “scientific and technological achievements”, “policies and

regulations”, “file download” and so on are all done by means of news display.

11.4 Project Facilities Management Platform

11.4.1 Network Platform Background Basic Information Description

11.4.1.1 Backend Administration Notes

Temporary backend URL: www.nswaitertest.com/tj_admin; User name: admin Password: admin320

11.4.2 Network Platform Background Instructions

The backend we use to manage the construction of the platform fully corresponds to the frontend:

For each column on the frontend, a corresponding information processing center can be found on the backend.

http://www.nswaitertest.com/tj_admin


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Home page large image management is done in the background.

11.4.3 Home Page Navigation Management

(1) About Us Management

About Us Management in the background: Content Management - Column Content - Operate on the About Us page:

Work such as Edit Text and Insert Image is performed here. In the background: Content Management - Column Content - Add and maintain on the Work List page:

(2)Notices and Announcements Management

In the background: Content Management - Column Management - Operate on the List of Notices and Announcements page:


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(3)Scientific and Technological Achievements Management

In the background: Content Management - Column Management - Manage on the List of Scientific and Technological Achievements page:

(4) Policies and Regulations Management

In the background: Content Management - Column Management - Manage on the List of Policies and Regulations page:

Click on the corresponding column to add, modify or maintain the corresponding content.

(5)Document Download Management

In the background: Content Management - Column Management - Manage on the List of Documents Available for Download page:


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Click on the corresponding column to add, modify or maintain the corresponding content.

(6) Contact Us Management

In the background: Content Management - Column Management - Add, modify and maintain content on the Contact Us page

(7) Links Are Separately Managed Here in the Background

(8)Home Navigation Sub-sections to Maintain Changes

TA-8963 PRC Final Report Chapter XII

313

❖ Second, in the process of development, it is also a need to develop special

technology appropriate for fly ash treatment in waste incineration plants in

China by actively drawing lessons from foreign advanced experience and

combining with China's actual conditions so as to realize independent

intellectual property rights, industrialization of treatment technology of fly ash

and full economic and social benefits;

❖ Third, with the development of technology, it is hopeful to realize fly ash re-

utilization. Main chemical composition of fly ash is almost the same as that of

blast furnace slag, pulverized fuel ash, etc., so incineration fly ash has a

certain utilization value. Technically, it can be developed into a kind of

auxiliary cementitious material, further enhancing fly ash treatment work.

Thus, resource re-utilization can be realized, efficiency improved,

environmental pollution reduced and cost saved. Therefore, re-utilization is

the development trend of fly ash treatment work in the future.

(3) Unveiling specifications. To overcome operation difficulties during the stabilization,

resources utilization and disposal process of incineration fly ash, on the basis of

reviewing existing laws and regulations, it is recommended that specifications for

resources utilization technology, treatment and disposal modes, as well as prevention

and control on environmental pollution, product requirements, innocent degree and

other respects of fly ash in different regions and of different sources against non-

standard treatment, disposal and resources utilization by some enterprises without any

treatment in advance or after simple cement solidification, which will easily trigger new

environmental pollution and so on.

12.2.4 Strengthening Source Reduction

727. Fly ash in China is under complicated conditions, and front-end extensive

lifestyle caused by indiscriminate collection and extensive management of the front-

end waste is bound to lead to problems in the back end. Content of certain substances

in waste incineration fly ash is high because content of those substances in the waste

is high. For example, incineration of food waste mixed with plastic waste finally leads

to high content of inorganic chlorine and organochlorine in the fly ash. In the country

that waste classification is carried out soundly, the content of chlorine is much lower

than that in China and the content of heavy metals in fly ash is very low. Most of the

hazardous substances in the fly ash are caused by poor front-end classification, from

which we can see the significance for China to promote waste classification.

TA-8963 PRC Final Report Chapter XII

314

728. It is recommend to use clean energy and raw materials, reduce excessive use

of packaging materials, introduce minimally processed vegetables and clean

agricultural and sideline products to the city, carry out resources comprehensive

utilization, promote scientific waste classification, thus reduce MSW amount during the

process of product production, circulation and consumption; realize source reduction

for fly ash generated from waste incineration disposal.

TA-8963 PRC Final Report References

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TA-8963 PRC Final Report Appendices

321

Appendices

Appendix 1 Summary of Workshops

Appendix 2 Summary of Surveys

Appendix 3 Summary of International Study Tour

Appendix 4 Draft Technical Specification and Policy for Municipal Solid

Waste Incineration Fly Ash

Appendix 4.1 Pollution Control Technical Specification for Municipal Solid Waste Incineration Fly Ash

Appendix 4.2 Pollution Control Technical Policy for Municipal Solid Waste Incineration Fly Ash

Appendix 5 The Engineering Manager System of Waste Processing Plant

and Personnel Training in Japan