organics based foulants analyses of hollow-fiber uf ...dwl/conference/organics based foulants... ·...

Organics based foulants analyses of hollow-fiber UF membranes in a drinking water treatment plant

Jongkwan Parka, Kangmin Chonb, Eunyoung Kanga, Kyongmi Chona

Heekyong Ohc, and Jaeweon Choa

International Conference on MEMBRANES IN DRINKING AND INDUSTRIAL WATER PRODUCTION

10–12 September 2012 Leeuwarden, The Netherlands

a Gwangju Institute of Science and Technology (GIST) b Eawag, Swiss Federal Institute of Aquatic Science and Technology

c Environmental Technology Research Team, DAEWOO E&C

Preview of study

PS Protein

Lignin PHA

Lipid

Foulants analysis by pyrolysis GC/MS Membrane Autopsy

Study of foulants’ origin Study of membrane characteristics

Membrane fouling

• Membrane fouling is a major constraint in membrane processes.

• It is impossible to block a membrane fouling, but possible to reduce it.

• Understanding of foulants is important.

Types of membrane fouling

Biofouling

Colloidal

fouling

Inorganic

Fouling

(scaling)

Organic

fouling

Colloidal

Fouling

Biofouling

How to reduce membrane fouling

Membrane cleaning

• Physical methods

Forward flushing Backwashing Vibrations

Cleaning agent Alkaline/acidic solutions

• Chemical methods

Backwashing

Alkaline/acidic solutions

Commonly used methods

Objectives

• Characterization of foulants according to the cleaning methods

(backwashing and alkaline/acidic solution)

• Providing information about fouled hollow fiber membrane through a membrane autopsy

Pilot scale system

Duration of operation : 18 months Cleaning in place (CIP) : 1 time Effective flux maintenance (EFM) : 16 times

mixing coagulation sedimentation UF membrane

Sampling

H2L membrane (Korea) Ultrafiltration membrane (0.05 ㎛)

Hollow fiber membrane Polyvinylidene fluoride (PVDF)

Fouled UF membrane

Alkaline solution (NaOH 300mg/L, NaOCl 3,000 mg/L)

Sample 1

Module A

Module B

Sampling

Acidic solution (H2SO4 30,000 mg/L)

H2L membrane (Korea) Ultrafiltration membrane (0.05 ㎛)

Hollow fiber membrane Polyvinylidene fluoride (PVDF)

Sample 1 Sample 2

Module A

Module B

Fouled UF membrane

Curie-point Pyrolysis GC/MS

Curi-point pyrolyzer: JCI-22, JAI GC/MS: 7890A Agilent/ 5975C Agilent Column: DB-5MS Agilent (30m x 0.25 mm x 0.25чm)

Column temp. programming : from 40 ℃ to 300 ℃ at a rate of 7 ℃ /min Py-GC interface temp. : 250 ℃ EI voltage : 70 eV mass range : 40 ~ 500 amu

Curie-point temp. : 590 ℃ Purging gas : He Heating rate : 590 ℃ / 0.16 sec Hold time : 5 sec Sample loading wt. : 0.1~0.5 mg

Alkaline solution Acidic solution

Results of Curie-point Pyrolysis GC/MS

There are two reasons 1. Most of organic matters dissolve in alkaline solution. 2. Amount of salt in injected samples

Sample collecting Concentration Freeze-dry

foulants for pyrolysis

Salt effect - Reduce organic portion

Sample preparation of Pyrolysis GC/MS

Alkaline solution

PS

Protein

Lignin PHA

Lipid

Results of Curie-point Pyrolysis GC/MS

Microbial originated foulants were dominant

25 %

33 %

15 % 22 %

5 %

Polysaccharide (PS) Amino sugar (AS) Polyhydroxy aromatic compounds (PHA)

Microbial originated foulants

Plant originated foulants

Autopsy for specific information

• Membrane surface

• Foulants

• Bacterial community

composition

Membrane Autopsy

Total 6 sections

Section A Section B Section C

Inner A1 B1 C1

Outer A2 B2 C2

Flow direction

A B C

Outer

Inner

Three modules for test

Fiber 1 (F①) : Backwashing

Fiber 2 (F②) : Backwashing + Alkaline cleaning

Fiber 3 (F③) : Backwashing + Alkaline + Acidic cleaning

Number of fibers : 20 Length : 23.5 cm Surface area : 0.015 m2

Lab-scale membrane system

Feed Pump

FM P1

FM P2

FM P3

Ho

llow

fibe

r UF

Concentrated solution

Permeate

The schematic diagram of hollow fiber membrane system

Experimental procedure

Fouled membrane

F①

F②

F③

Back washing

Breaking module

Breaking module

Breaking module

Alkaline cleaning

Acidic cleaning

Membrane surface (Outer)

80 x

1000 x

F② F③ After Backwashing

F① After Alkaline cleaning After Acidic cleaning

80 x

1000 x

Membrane surface (Inner)

F① F② F③ After Backwashing After Alkaline cleaning After Acidic cleaning

Amount of foulants onto membranes was too low

Foulants after backwashing

F① F③

Protein

Lignin

PHA Lipid

Protein

Lignin

PHA

Lipid

Protein

Lignin

PHA

Lipid

F②

19 %

43 %

27 % 9 %

24 % 30 %

42 %

21 %

45 %

28 %


PS

Protein

Lignin

PHA

Lipid

Foulants comparison

F③

PS

Protein

Lignin PHA

Lipid

Backwashing Alkaline solution

Alkaline solution can remove the microbial originated foulants

21 %

45 %

28 %

3 %

3 %

33 %

25 %

15 % 22 %

5 %

Microbial originated foulants

Plant originated foulants


0

20

40

60

80

100

Proteobacteria Firmicutes

Per

cen

tage

Rank Taxonomy Name SUM

(Ratio) Sum

(Number)

Phylum Bacteria – Proteobacteria Proteobacteria 78.38 10321

Phylum Bacteria – Firmicutes Firmicutes 21.59 2843

Phylum Bacteria – Actinobacteria Actinobacteria 0.02 3

Phylum Bacteria – Bacteroidetes Bacteroidetes 0.01 1

Taxonomic assignment of 16S rRNA gene sequences retrieved from membrane biofilm

Anaerobic sludge systems Biofouling layers (Gao et al., 2010; Patil et al., 2010)

Bacterial community composition

Pyrosequencing was carried out at ChunLab. (seoul, Korea)

Rank Taxonomy Name SUM

(Ratio) Sum

(Number) Class Bacteria – Proteobacteria – Betaproteobacteria Betaproteobacteria 44.78 5897 Class Bacteria – Proteobacteria – Gammaproteobacteria Gammaproteobacteria 29.76 3919 Class Bacteria – Firmicutes – Bacilli Bacilli 20.45 2693 Class Bacteria – Proteobacteria – Alphaproteobacteria Alphaproteobacteria 3.84 505 Class Bacteria – Firmicutes – Clostridia Clostridia 1.13 149 Class Bacteria – Actinobacteria - Actinobacteria_c Actinobacteria_c 0.02 3 Class Bacteria – Bacteroidetes – Cytophagia Cytophagia 0.01 1 Class Bacteria – Firmicutes - Symbiobacterium_c Symbiobacterium_c 0.01 1

0 20 40 60 80 100

Alphaproteobacteria

Betaproteobacteria

Gammaproteobacteria

Bacilli

Clostridia

Percentage

freshwater environment biofouling development

(Chen et al., 2004; Chon et al., 2009)


Aerobic biosystem

(Yanqin et al., 2011)


0 20 40 60 80 100

Sphingomonas

Tardiphaga

Janthinobacterium

Herbaspirillum

Massilia

Pseudomonas

Tumebacillus

Brevibacillus

Paenibacillaceae_uc

Bacillales_uc_g

Alicyclobacillaceae_uc

Percentage

Alphaproteobacteria

Betaproteobacteria

Gammaproteobacteria

Bacilli



2. Membrane autopsy

• Membrane surfaces were not different from each cleaning step.

• Firmicutes Bacilli ( 20 % ) Proteobacteria Betaproteobacteria ( 44 %) Gammaproteobacteria ( 30 % )

1. Foulants analysis

Summary

• Alkaline cleaning can remove polysaccharide portion.

Microbial originated foulants can be removed.

were dominant. )

Acknowledgement

This research was supported by Korea Ministry of Environment as “The Eco-Innovation Project (Global Top Project)”.

Presenter : Jongkwan park, [email protected] Advisor : Jaeweon cho, [email protected]

organics based foulants analyses of hollow-fiber uf ...dwl/conference/organics based foulants... ·...

Documents