laboratory type textile etp plant by israfil alam rana

Israfil Alam… [email protected] (+88 01717123339)

Designing, Construction and Validation

of

Laboratory Type

Textile Effluent Treatment Plant


Designing, Construction and Validation

of Laboratory Type Textile Effluent

Treatment Plant

Prepared by:

Mohammad Israfil Alam

Pre-registration no.: 1299

TTH ID: SEU-04

Department of Textile Engineering

SOUTHEAST UNIVERSITY

Mobile: +88 01717123339

Email: [email protected]

Supervisor:

Dr. Arun Kanti Guha

Assistant Professor

Department of Textile Engineering

SOUTHEAST UNIVERSITY

Mobile: +88 01718833461

Email: [email protected]

mailto:[email protected]

mailto:[email protected]


Approval

This is to Certify that Mr. Mohammad Israfil Alam has completed a study under

my supervision entitled “Designing, Construction and Validation of Laboratory

Type Textile Effluent Treatment Plant” to submit an assignment to the authority of

Textile Talent Hunt Competition, 2010.


Table of Contents

Abstract ...................................................................................................................................... I

1. Introduction .........................................................................................................................1

1.1 Pollution by Textiles .....................................................................................................1

1.2 Characterization of Textile Wastewater of Different Areas of Bangladesh .....................3

1.3 Necessity of Laboratory Type Textile ETP ....................................................................4

2. Construction of Laboratory Type Textile ETP ......................................................................5

2.1 List of costs of accessories ............................................................................................6

2.2 Plant Layout: Drawing Design ......................................................................................7

2.3 Plant Layout: Image .....................................................................................................8

2.4 Capacity of Different Tank ............................................................................................9

2.5 Devices Used in ETP Model ....................................................................................... 10

3. Experimental ...................................................................................................................... 11

3.1 ETP Flow Chart .............................................................................................................. 12

3.2 Treatment Processes ....................................................................................................... 13

3.2.1 Screening ................................................................................................................ 13

3.2.2 Equalization ............................................................................................................ 13

3.2.3 Primary Clarifier: .................................................................................................... 14

3.2.4 Oxidation ................................................................................................................ 15

3.2.5 Decoloring unit ........................................................................................................ 15

3.2.6 Secondary Clarifier .................................................................................................. 16

3.2.7 Sludge Processing Unit ............................................................................................ 16

3.2.8 Discharge ................................................................................................................. 16

3.2.9 Experiment Results: Sample 01 ............................................................................... 17



4. Results & Discussion ......................................................................................................... 20

5. Conclusion ......................................................................................................................... 23

6. Acknowledgements ............................................................................................................ 24

7. References ......................................................................................................................... 25


Abstract:

The rapid growth of textile industries creates environmental pollution, mainly water pollution.

The reason of water pollution is lack of appropriate environmental management in textiles in

Bangladesh.[1] Wastewater is the major environmental issue of the textile industries besides other

minor issues like solid waste, residual waste etc. In Bangladesh most of the industrial units are

located along the banks of the rivers and they do not use Effluent Treatment Plant (ETP) for

wastewater. As a consequence, industrial units drain effluent directly into the rivers without

consideration of the environment. Department of Environment (DoE) has visited 466 factories

that produce harmful liquid wastes. Only 104 of them were found to have installed ETPs.

However, only 56 ETPs were found to be in use by the owners. The rest of the ETPs were either

closed to save operating cost or were out of order. Setup an effluent treatment plant is mandatory

for a factory today. But due to its high construction cost many factories directly discharge

effluent into the drain. In that case it is essential to know about textile wastewater management

from the beginning of our engineering life. To this view point a laboratory type textile effluent

treatment plant is constructed. We treat our laboratory wastewater in this ETP. Three samples

were collected from dyeing laboratory. Before treatment pH was 11, 10, and 9 and after

treatment pH is 7, 7 & 7 respectively. Before treatment color was deep blue, deep red & deep

yellow and after treatment color is pale blue, pale red & pale yellow respectively. BOD, COD,

TDS, TSS etc values could not be analyzed in laboratory due to unavailability of instruments.

These tests required high cost and could not manage. This ETP model can be used as practical

class for undergraduate textile students. The laboratory type ETP is essential in all laboratory of

textile engineering department of all universities. This will help to know how to treat textile

wastewater practically which is difficult to learn in factory.


1. Introduction:

In this industrialized age, environmental pollution is a matter of great concern. Surface water

pollution is one of the elements of environmental pollution. Chemical processing industries

especially textile processing industries are claimed to produce huge effluent to discharge in our

rivers. A complex mixture of hazardous chemicals both organic and inorganic is discharged into

the water bodies from all these industries, usually without treatment. It is well known that textile

mills consume large volume of water for various processes such as sizing, desizing, scouring,

bleaching, mercerizing, dyeing, printing, finishing and washing. Due to the nature of various

chemical processing of textiles, large volume of wastewater with numerous pollutants are

discharged everyday.

1.1 Pollution by Textiles:

Especially the chemical processing industries of textile like dyeing, printing, finishing &

washing are mainly responsible for water pollution whereas the spinning, weaving, knitting,

nonwoven, garment manufacturing etc have little or no contribution in water pollution.

A flow chart of textile manufacturing:

Figure 1. Textile Manufacturing Processes[2]


22 26

6996

0

20

40

60

80

100

120

Green Orange-A Orange-B Red

Table1. Volume of Effluent produced by different processing of textiles.[2]

Department of Environment issues the Environmental Clearance Certificate to the various

industries classified in categories of Green, Orange-A, Orange-B & Red in consideration of their

site and impact on the environment. As per The Environment Conservation Rules 1997, number

of categorized industries listed below:[2]

Textile wet processes are logically in red category. They have strong rules of these types of

industries including the preset up of Effluent Treatment Plant (ETP) plant in giving time period

to get the Environmental Clearance Certificate which is obvious to get utility connection like

gas, water etc.

Process Name Production per Day Amount of Effluent

produced per day (m3)

Weaving preparation 4.14 million meters/day 1118

Yarn dyeing 150 tones/day 16,500

Knit processing 1430 tones/day 1,28,700

Woven processing 3.84 million meters/day 84,500

Garment washing & dyeing 500000 pcs/day 8500

Category

Fact

ory

Figure 02. A column diagram of a plot of factory Vs. category reported by DoE, Bangladesh.


3226

498 538

2808 2676

0

500

1000

1500

2000

2500

3000

3500

Savar Ashulia Dhamrai Gazipur Narshandi

10.7

7.2 6.9

9.8

14

0

2

4

6

8

10

12

14

16

Savar Ashulia Dhamrai Gazipur Narshandi

1.2 Characterization of Textile Wastewater of Different Areas of

Bangladesh:[3]

We have to know pollution levels of different textile industrial zones. Textile wastewater

collected from different areas are analyzed in laboratory and found high pH and Total Dissolved

Solids (TDS) values in almost all areas. Maximum values of pH and TDS of different areas are

given below in column diagrams.

TDS

mg/

L

Figure 3. A column diagram of maximum values of TDS (mg/L) of wastewater of different areas

pH

p

H

Figure 4. A column diagram of maximum values of pH of wastewater of different areas


1.3 Necessity of Laboratory Type Textile ETP:

Laboratory type effluent treatment plant is a new concept in Bangladesh. Generally ETP setup

cost is high. The cost of ETP varies from Tk 1Cr to 5Cr depending upon the volume of

effluent.[2] Similarly, the processing cost of wastewater in ETP varies upon the processing

materials & process type. But a laboratory type ETP is easy & cheap to construct and treatment

cost is also cheap. Not also the textile industries produces wastewater, but also in every

university which have Textile Engineering Department & dyeing lab also produces effluents

during different dyeing practical classes. After practical classes generally the effluents are

discharged into the sewerage line. This effluent mixing with sewerage waste and increases the

pollution rate of drain water. If we use laboratory type ETP, firstly we can treat the effluent

produced from different practical classes and secondly we can easily learn how to operate ETP

as like as industry. We can also learn the total treatment process of ETP that could help our

future industrial job. We can collect effluents from different textile industry and treat it as like a

practical class of Effluent Treatment Plant. Even now Effluent Treatment Plant is mandatory to

setup of any new dyeing industry otherwise they will not get gas & electricity connection that’s

why it is important to know about ETP for future job life. ETP is also a part of textile

undergraduate engineering syllabus. So it is important to know about ETP and in that case a

laboratory type ETP can give all solution. Any research type activities related to wastewater can

be easily done in laboratory. A laboratory ETP construction cost is about Taka 5,000 to 6,000

with chemical cost. Its construction process is easy and operating cost is very low as compared to

industrial ETP.


2. Construction of Laboratory Type Textile ETP:

Construction of laboratory type textile ETP is an innovative work. At the beginning, most

important thing is make a layout plan according to model shape & area. Then calculate the

different tank areas according to its process. And after layout another important thing is

purchasing of construction materials. Construction materials are purchased from three different

places in Dhaka. Pumps and cork sheets are purchased from Kataban area, different plastic boxes

from old Dhaka and remaining materials from Badda area. Chemicals are purchased from

Hatkhola road. After collecting all raw materials, at first frame and boundary of plant was

constructed according to plan layout. After that cork sheets are placed inside the wood frame and

cut it according to different sizes of plastic box. Cork sheets are attached by adhesive & then the

boxes are placed inside the cork sheet. Air flow pipes and bubble creators are attached by joint &

adhesive respectively in different tank. At final stage a thin polyethylene sheet is attached on the

cork sheet as a waterproof surface.

Figure 5. Different steps of Construction of Laboratory Type Textile ETP.


2.1 List of costs of accessories:

Serial Product name Quantity Origin Unit price Amount (BDT)

01 Air pump 1 China 200 200

02 Filter pump 3 China 400 1200

03 Hard board 1 (8’ x 4’) Bangladesh 300 300

04 Ply Wood 5 Bangladesh - 150

05 Board pin 100 gm Bangladesh 15 15

06 Cork sheet 2 (4’ x 8’, 1”)

1 (4’ x 8’, 3/4”) Bangladesh

140

110

180

110

07 Hekso bleed 2 China 15 30

08 Measuring tape 1 China 25 25

09 Adhesive 2 India 60 120

10 Anti cutter 1 China 35 35

11 Polythin sheet 2 Bangladesh 15 30

12 Plastic box 7 Bangladesh - 280

13 Dropper 5 Bangladesh 5 25

14 Multi plug 1 China 300 300

15 Polyester net 1 Bangladesh 5 5

16 PVC pipe 2 (1/2 “ dia) Bangladesh 25 50

17 PVC Pipe joint 10 Bangladesh 5 50

18 Air flow pipe 5 yds China 8 40

19 Key & joint 10 Bangladesh 5 40

20 Air bubble creator 5 China 50 250

21 Making & other cost - - 300

Total 3735

Chemicals Cost/Kg (BDT)

Lime 150 Ferrous sulfate 200 Polyelectrolyte 800 De colorant 16 Hydrochloric acid 25

Table 3. List of Costs of Chemicals

Table 2. List of costs of accessories*

*Prices may be changed as per market value.


2.2 Plant Layout: Drawing Design

A Screening unit B Equalizing unit C Primary clarifier D Oxidizing unit E Decoloring unit F Secondary clarifier G Sludge processing unit H Storage tank I Outlet J Input power plug K Power unit L Air compressor pump

Water Pump

Liquid flow pipe

Overflow pipe

Power cord

Air flow pipe

Bubble creator pipe

Chemical dosing unit

L

A

B

C

D

G

F

E

H

K

J

I


2.3 Plant Layout: Image


5.0 L

2.5

L

7.0 L

1.5 L

0.5 L

0.5

L

105 cm

80 c

m

2.4 Capacity of Different Tank:

Name Capacity

A Screening 1.0 L

B Equalization Tank 5.0 L

C Primary Clarifier 2.5 L

D Oxidation Tank 7.0 L

E Decoloring Unit 1.5 L

F Secondary Clarifier 0.5 L

G Discharge 0.5 L

H Sludge process unit 0.5 L

E

A

B

C D

F

G

H


2.5 Devices Used in ETP Model:

Oxygen pump:[4]

ü Long lasting performance

ü Two speed control system

ü Twin outlet

ü Energy saving design

ü Low noice and big output

Internal filter pump:

ü Long lasting performance

ü Suitable for fresh & salt water

ü Fully submersible

ü Energy saving design

ü Low noice and big output

Country of origin China

Manufacturer company Song Bao Electric Appliance Co. Ltd.

Model no. SB-348A

Input power AC 220-240V 5W

Output 2 x 4L/min

Pressure 0.02 x 2 Mpa

Country of origin China

Manufacturer company Song Bao Electric Appliance Co. Ltd.

Model no. WP-1200F

Input power AC 220-240V 15W

Output flow 880L/Hr (max)

Table 4. Specification of Oxygen Pump

Table 5. Specificaltion of Filter Pump


3. Experimental:

In laboratory, three samples were analyzed. Three samples were tested in three separate days. High

pH obtained in all samples and got standard results after treatment. To avoid contamination the ETP

cleaned properly before treatment of each new sample. pH, color & odor of samples were analyzed.

BOD, COD, TDS, TSS etc values could not be analyzed in laboratory due to unavailability of

instruments. These tests required high cost and could not manage.

Figure 6. Experiment with Laboratory type Textile ETP


3.1 ETP Flow Chart:

Screening Equalization Tank

Primary Clarifier Oxidation

Tank

Decoloring Unit

Secondary Clarifier

Sludge processing

unit

Influent

Discharge


3.2 Treatment Processes:

Total treatment process contains following steps:

3.2.1 Screening:

The raw waste is passed through a manual bar screen to remove floating suspended matters like

polythene bags, rags etc. The bar screen is cleaned manually by hand. In this model collected

wastewater is passed through the screening unit to the equalization tank. Mainly there are no any

coarse particles used in laboratory.

3.2.2 Equalization:

The screened waste is then collected in the equalization tank. In equalization tank the wastewater is

kept 2 hours for cooling. The equalization tank is provided with air grids to keep the suspended solids

in suspension and to ensure proper mixing is achieved. The air grids are provided by bubble creator

connected to air blower.

Figure 7. Screening & Equalization tank


3.2.3 Primary Clarifier:

The equalized effluent is then pumped into the primary clarifier for coagulation, flocculation and pH

correction. The pump situated in the equalization tank & flows wastewater when switch on. In this unit

liquid waste is treated with lime, ferrous sulfate or alumn and polyelectrolyte so that sludge is

separated through coagulation and flocculation. Precipitated sludge is passed to sludge processing unit.

pH can be controlled by adding concentrated hydrochloric acid in between coagulation and

flocculation processes. The pH is kept around from 6.5 to 7.5. This tank is also provided with air grids

to keep the suspended solids in suspension and to ensure proper reaction of coagulation and

flocculation processes. The air grids are provided by bubble creator connected with air blowers. The

total reaction time is taken about 1.5 hours to 2 hours.

Steps Retention Time Chemicals Dosing

Equalization 2 hours Lime 1 g/L Primary clarifier 1.5 - 2 hours Ferrous sulfate 1 g/L

Oxidation 1 hour Polyelectrolyte 1 g/L De coloring unit 1 hour De colorant 10 ml/L

Secondary clarifier 2 hours Hydrochloric acid 20 ml/L

Figure 8. Primary Clarifier

Table 6. Retention Time & Chemical dosing


3.2.4 Oxidation:

The upper level liquid waste of secondary clarifier is passed to oxidation tank and precipitated sludge

is then separated to sludge processing unit by pump. The biological treatment is designed on extended

aeration principle. The aeration is provided with fixed type surface aerator for providing the required

oxygen for the biological degradation of organic pollutant. In our experiments we could not manage

bacteria & that’s why oxidation process was skipped from our experiments. In this unit the liquid

waste is kept about 1 hour for proper reaction of chemicals.

3.2.5 Decoloring unit:

After biological treatment the liquid waste is passed to the decoloring unit by pump. In this tank

required amount of decoloring agent is dosed to remove the organic color of wastewater. The reaction

time is about 50 to 60 minutes.

Figure 9. Oxidation Tank Figure 10. Decolorant Tank


3.2.6 Secondary Clarifier:

After decoloring unit the liquid waste is passed to the secondary clarifier. In secondary clarifier the

upper layer of the liquid waste remains stationary and liquid waste is passed from the lower level of the

secondary clarifier to the sludge processing unit so that remaining dissolved solids are separated as

sludge.

3.2.7 Sludge Processing Unit:

The sludge underflow from the primary and secondary clarifier is taken into sludge drying beds for

dewatering. The dewatered sludge is scrapped manually and disposed off suitably.

3.2.8 Discharge:

Over flow of liquid from the secondary clarifier is stored in discharge unit. This water is then drain out

to the environment.

Figure 11. Secondary Clarifier

Figure 13. Discharge Unit

Figure 12. Sludge Thickening Unit


3.2.9 Experiment Results: Sample 01

Parameters Before treatment After treatment Remarks

Color Deep Blue Pale Blue Decolorised

pH 11.0 7.0 pH maintained as discharge limit

Odor Odorless Odorless

Figure 15.Before Decolorization & after Decolorization

Figure 14.Before pH 11 & after pH 7.0

Table 7. Validation based on experimental results




Color Deep Red Pale Red Decolorised





Figure 16.Before pH & 11 after pH 7.0




Color Decolorised





Figure 18.Before pH 11 & after: pH 7.0


4. Results & Discussion:

Treatment of effluent from textile dyeing industries is required to meet the national and international

effluent discharge standard. It is required to meet the national standard to abide by the rules set up by

the Government and to meet the international standard to comply with the standard setup by the

buyers. In Bangladesh, Department of Environment is the regulatory body to monitor and control the

pollution from the industrial discharge. It has set up the industrial discharge standards for the

industries.

Table 10. Inland Surface Limits for textile liquid waste according to the National Effluent Quality

Standards (NEQS) guided by DoE of Bangladesh.[5]

Parameters Limits

pH 6.0-9.0

BOD5 (20oC) 50 mg/L

COD 200 mg/L

TSS 100 mg/L

TDS 2100 mg/L

Oil & Grease 10 mg/L

DoE has not set up any color standard for the industries. Although as a health and environmental issue

color is less of a concern than many of the other parameters, it is an issue in dye house effluent because

unlike other pollutants it is so visible. Reducing color is therefore important for the public perception

of a factory.


Our laboratory experiments got standard limits after treatment in each sample. Laboratory treatment

has given result on pH, color, temperature & odor of samples. TDS, TSS, BOD, COD was not found

because of unavailability of instruments.

Table 11. Lab Experiment Result Based on pH.

Sample No. pH

Remarks Before Treatment After Treatment

Sample 01 11.0 7.0 Satisfactory



Table 12. Lab Experiment Result Based on color.

Sample No. Color

Remarks Before Treatment After Treatment

Sample 01 Deep Blue Pale Blue Satisfactory

Sample 02 Deep Red Pale Red Satisfactory

Sample 03 Deep Yellow Pale Yellow Satisfactory

High pH values were obtained in every sample before treatment in ETP model and after treatment in

this model standard limits were found on each sample. It proves that the treatment process was

correctly done as like factory.

Now a day it is essential to know about textile wastewater management as a textile engineer. To this

view point a laboratory type textile effluent treatment plant can be a good solution to know about

textile wastewater management system. By this ETP model any kinds of wastewater related treatment

can be done.


Practical Classes: By this ETP model practical classes about textile wastewater management can be

taken. It is helpful for a student to know easily how textile wastewater is treating. In fact now a day

textile wastewater management is a part of syllabus of undergraduate student. That’s why every

university which has Textile engineering department is essential to have an ETP model in their

laboratory.

Dyeing wastewater treatment: Wastewater from textile dyeing laboratory is directly discharged on

sewerage line during practical classes. This effluent mixing with sewerage waste increases the

pollution rate of drain water. But this wastewater can be stored in a drum and can treat by this ETP

model in laboratory.

Research on wastewater: Any research type activities related to wastewater can be easily done in

laboratory by using this ETP model. Wastewater collected from different areas can be analyzed by this

model.


5. Conclusion:

In the way of employment-intensive industrialization, textile industries are playing an utmost

important role offering tremendous opportunities for the economy of Bangladesh. But hasty and

unplanned clustered growth of industries leads to adverse environmental consequence in an alarming

way. Large quantity of water associated with the production of a number of dyeing and textile

industries releases toxic wastewater rich in dye and chemicals to the environment that result in sever

water body pollution. For undergraduate studies in Textile Engineering there are several Universities in

public and private sectors launched B.Sc in Textile Engineering program. At the department of Textile

Engineering dyeing laboratory is essential for practical classes in wet processing technology. Effluent

is generated after dyeing lab classes in Universities. It is also essential to treat this effluent. So

laboratory type ETP is mandatory in these universities to treat wastewater generated after practical

classes. This type of ETP designing, construction and validation methods reported in this assignment.

So it would be nice if this type of innovative laboratory type ETP is constructed and used for lab

wastewater treatment.


6. Acknowledgements:

By the name of Allah at first I would like to thank Bangladesh Textile Today for arranging such a

challenging competition. It is a great opportunity for me to participate in this competition.

In this second step of Textile Talent Hunt, my paper design subject is “Designing, Construction and

Validation of Laboratory Type Textile Effluent Treatment Plant”. It is a good subject and

awareness for people who are thinking about the textile wastewater management system. I would like

to give thank my Supervisor Dr. Arun Kanti Guha for his support to make this paper successful.

Without his support it will more difficult to make this paper successful. I am also grateful to Prof.

Fakhrul Hasan Murad, Chairman, Department of Textile Engineering for financial and moral support

to complete this work. After him I would like to give thank our laboratory teacher Mr. Yeamin Sarker.

He helped me a lot to collect wastewater. In this paper I have tried to give my best performance to

make this paper successful.

Again thank to Bangladesh Textile Today for arranging Textile Talent Hunt -2010. I think in future

they will organize more programs which will help us in our future life.


7. References:

1. Arun Kanti Guha, Md. Shariful Islam, “Environmental Management in Textile”, Bangladesh

Textile Today, 2(1), 43-48

2. A.S.M. Tareq Amin, Md. Ershad Khan, “Surface Water Pollution: Contribution of Textile

Sector and Way Out”, Bangladesh Textile Today, 2(3), 16-20.

3. Md. Imdadul Haque, Arun Kanti Guha, “Characterization of Textile Wastewater of Different

Areas of Bangladesh”, Bangladesh Textile Today, 3(1), 28-31.

4. http://www.newsobo.com

5. http://www.doe-bd.com

http://www.newsobo.com/

laboratory type textile etp plant by israfil alam rana

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