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Unraveling Membrane Fouling Induced by Chlorinated Water Versus Surface Water:Biofouling Properties and Microbiological Investigation

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Engineering 2022年第8期8卷 154-164页

作者： Li Zhang Lei Xu Nigel Graham Wenzheng Yu State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Department of Civil and Environmental Engineering Imperial College LondonSouth Kensington CampusLondon SW72AZUK

Chlorine is usually applied in the urban water treatment process to deactivate pathogens and prevent waterborne diseases.As a pre-treatment,it remains unclear whether chlorinated water can effectively alleviate membrane fouling during ultrafiltration(UF).In this study,tap water was investigated for its effect on biofilm formation and biofouling in a gravity-driven membrane(GDM)filtration system.For comparison,biofilm/biofouling with untreated surface(lake)water was studied in parallel.It was found that more severe membrane fouling occurred with the filtration of tap water than lake water,and larger quantities of polysaccharide and extracellular DNA(eDNA)were present in the tap-water biofilm than in the lake-water biofilm.The tap-water biofilm had a densely compact morphology.In contrast,a porous,spider-like structure was observed for the lake-water biofilm,which was assumed to be associated with the bacteria in the biofilm.This hypothesis was verified by 16S ribosomal RNA(rRNA)sequencing,which demonstrated that Xanthobacter was the dominant taxon in the tap-water biofilm.Additionally,membrane hydrophobicity/hydrophilicity played a minor role in affecting the membrane fouling properties and microbial community.This study revealed the significant role of chlorine-resistant bacteria in biofouling formation and provides a deeper understanding of membrane fouling,which can potentially aid in searching for effective ways of controlling membrane fouling.

关键词： Membrane fouling Biofilm GDM filtration technology ultrafiltration Chlorine-resistant bacteria Hydrophilicity

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Membrane Fouling Alleviation by Chemically Enhanced Backwashing in Treating Algae-Containing Surface Water: From Bench-Scale to Full-Scale Application

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Engineering 2022年第12期19卷 40-49页

作者： Xiaobin Tang Tiecheng Guo Haiqing Chang Xiao Yue Jinlong Wang Haikuan Yu Binghan Xie Xuewu Zhu Guibai Li Heng Liang State Key Laboratory of Urban Water Resource and Environment(SKLUWRE) School of EnvironmentHarbin Institute of TechnologyHarbin 150090China College of Architecture and Environment Sichuan UniversityChengdu 610207China College of Architecture and Civil Engineering Beijing University of TechnologyBeijing 100124China School of Marine Science and Technology Harbin Institute of Technology at WeihaiWeihai 264209China

ultrafiltration(UF)has been increasingly implemented in drinking water treatment plants;however,algae and their secretions can cause severe membrane fouling and pose great challenges to UF in practice.In this study,a simple and practical chemically enhanced backwashing(CEB)process was developed to address such issues using various cleaning reagents,including sodium hypochlorite(NaClO),sodium chloride(NaCl),sodium hydroxide(NaOH),sodium citrate,and their combinations.The results indicate that the type of chemical played a fundamental role in alleviating the hydraulically irreversible membrane fouling(HIMF),with NaClO as the best-performing reagent,followed by NaCl.Furthermore,a CEB process using a combination of NaClO with NaCl,NaOH,or sodium citrate delivered little improvement in the alleviation of membrane fouling compared with NaClO alone.The optimized dosage and dosing frequency of NaClO were 10 mg·L^(-1) two times per day.Long-term pilot-scale and full-scale experiments further verified the feasibility of the CEB process in relieving algae-derived membrane fouling.Compared with the conventional hydraulic backwashing without chemical involvement,the CEB process can effectively remove the organic foulants including biopolymers,humic substances,and proteinlike substances by means of oxidization,thereby weakening the cohesive forces between the organic foulants and the membrane surface.Therefore,the CEB process can efficiently alleviate the algae-related membrane fouling with lower chemical consumption,and is proposed as an alternative to control membrane fouling in treating the algae-containing surface water.

关键词： ultrafiltration Membrane fouling Hydraulically irreversible membrane fouling Chemically enhanced backwashing(CEB) Algae-containing surface water

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Preparation and properties of metal-PVA composite hydrophilic ultrafiltration membranes

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Journal of Central South University of Technology 2003年第2期10卷 117-121页

作者：邱运仁张启修 College of Chemistry and Chemical Engineering Central South University Metallurgical Separation Science and Technology Laboratory Central South University

Metal-polyvinyl alcohol(PVA) composite ultrafiltration membranes were prepared by coating a certain concentration of PVA solution on metallic fiber sintered membranes. The effects of preparation conditions, such as the coating solution concentration, sequence and times of coating, and heat-treatment on the properties of the composite membranes were studied. The results show that the hole diameter of the composite membrane decreases with the increase of the concentration of PVA, the hole diameter of composite membrane is different when the sequence of coating is different. When the higher concentration of PVA solution is used to coat the metallic membrane for the first time and the other smaller one for the second time, the hole diameter of the composite membrane is relatively small, compared with that of the composite membrane made by the smaller concentration of PVA solution for the first time and the other higher one for the second time. The holes of the composite membrane contract and the stability of the membrane is improved by heat treatment. When metal-PVA composite hydrophilic membranes are used to treat the oil/water emulsion with the concentration of 1 000 mg·L -1 , the retention is from 80% to 90%, and the permeate flux is from 15 L·m -2 ·h -1 to 40 L·m -2 ·h -1 at pressure of 0.2 to 0.3 MPa.

关键词： polyvinyl alcohol composite membrane hydrophilicity ultrafiltration modification

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Characterization of Natural Organic Matter and Disinfection Byproducts Formation Potential in Pilot-Scale Coagulation-ultrafiltration Membrane Combined Process in Winter

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Transactions of Tianjin University 2010年第5期16卷 328-335页

作者：张耀宗王启山何凤华丁莎莎 College of Environmental Science and Engineering Nankai University Tianjin TEDA Water Supply Corporation

A pilot-scale ultrafiltration membrane plant was set up for treating Luanhe River water with flocculating and precipitation process of waterworks.The aim is to investigate the variation and characteristics of natural organic matter and disinfection byproducts formation potential in the whole process in winter.The results show that dissolved organic matter(DOM),UV254,trihalomethanes formation potential(THMsFP) and haloacetic acids formation potential(HAAsFP) of Luanhe River water were mainly distributed in the range of molecular weight(MW) 30 kDa and MW<1 kDa.It is the DOM in water backwashing in up way that made significant contribution to the higher dissolved organic carbon content in membrane backwash water.However,UV254,THMsFP and HAAsFP were mainly distributed in the range of MW<1 kDa.The highest concentrations of specific THMsFP and specific HAAsFP appeared in the MW fraction of 3-10 kDa.CHCl3 was the major THMs species during MBW chlorination and occupied more than 60% of the total THMsFP.Dichloroacetic acid and trichloroacetic acid were the main components in HAAsFP.The concentration of THMsFP and HAAsFP in MBW was influenced by operation period.

关键词： THMsFP HAAsFP UV254 溶解有机物 ultrafiltration

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Apple Pectin Behavior Separated by ultrafiltration

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Agricultural Sciences in China 2009年第10期8卷 1193-1202页

作者： QIU Nong-xue TIAN Yu-xia QIAO Shu-tao DENG Hong College of Food Engineering and Nutrientional Science Shaanxi Normal University Xi＇an 710062 P.R. China College of Mechanical Instrument Engineering Xi ＇an University of Technology Xi＇an 710048 P.R. China

Separation conditions of ultrafiltration for apple pectin, weights and their structures and properties are studied and relations between apple pectin with different relative molecular Five kinds of ultrafiltration membranes with different molecular weight cut-offs are used to separate apple pectin. FT-IR and HPGC are used individually to determine the structures and monosaccharide composition of apple pectin with different relative molecular weights. In the case of transmembrane pressure difference of 0.08 MPa, material concentration of 1 g·L^-1, and temperature of 50℃, 6 kinds of apple pectins with different molecular weights have been obtained. Molecular weight of apple pectin is correspondingly related to its physicochemical properties. The galacturonic acid contents and esterification and gelatination degrees increase relatively with an increase in molecular weight, and the monosaccharide composition relatively increase much more. And at the same time, the ultrafiltration has a better role to play in decoloring apple pectin solution. Accordingly, this research can be used as a new method for in-depth exploration of apple pectin.

关键词： apple pectin ultrafiltration FT-IR GC

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A Pilot-scale Study on Coal Gasification Wastewater Reclamation Using Pretreatment Alternatives Combined with ultrafiltration and Reverse Osmosis

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Journal of Harbin Institute of Technology(New Series) 2015年第6期22卷 11-20页

作者： Qian Zhao Hongjun Han Fang Fang Peng Xu Kun Li Dexin Wang State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology

Aims to investigate the performance of the pilot-scale reclamation plant for coal gasification wastewater( CGW) using ultrafiltration and reverse osmosis with appropriate pretreatment alternatives,different pre-treatment alternatives- coagulation,adsorption,and ozonation methods were employed to treat the secondary effluent of coal gasification wastewater( SECGW) in a pilot-scale pressurized membrane system. The performance was compared to choose the most suitable pre-treatment alternative for the SECGW reclamation.Ozone reaction achieved highest COD removal efficiency( 79.6%- 91.0%),resulting in the stable normalized parameters of the subsequent ultrafiltration and reverse osmoses. In contrast,the coagulation and adsorption processes achieved only 32. 8%- 45. 7% and 53. 1%- 64. 6% decreases in COD,respectively. The residual organic pollutants in the reverse osmosis feed water led to an increase in normalized pressure drop and a decrease in normalized permeability( or membrane transference coefficient). The hydrophobic fraction was the main constituent( approx. 70% of DOC) in pretreated SECGW, and the hydrophobic-neutral fraction contributed mostly to the UV absorbance( 53%). Fluorescence excitation emission matrices revealed that ozonation removed most of the hydrophobic and aromatic proteins such as tyrosine and tryptophan which dominated in raw wastewater. The recalcitrant compounds such as phenolic compounds, heterocyclic compounds,especially long-chain hydrocarbons,which were easily attached to the membrane surface and contributed to organic fouling,could be oxidized and mineralized by ozone. Among the three pretreatments,ozonation showed highest removal efficiencies of hydrophobic and aromatic proteins,therefore resulting in highest normalized permeability.

关键词： coal gasification wastewater pretreatment ultrafiltration reverse osmosis ozonation

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Fouling of organic fractionation on ultrafiltration membrane for drinking water treatment:a case study

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Journal of Harbin Institute of Technology(New Series) 2010年第6期17卷 819-823页

作者：康华何文杰刘秀红王东 School of Municipal and Environmental Engineering Harbin Institute of Technology Tianjin WaterWorks Group Company Ltd Beijing Drainage Group Co.Ltd Changchun Water Group Co.Ltd

The aim of this study was to obtain a better understanding of the range of organic molecular weight(MW)causing membrane fouling through the comparison between direct UF and in-line coagulation(without settling)/UF process.The experimental results indicated that,when raw water with organics was treated and the MW of more than half of the organics was less than 1 kDa,membrane fouling was rather serious by only UF and coagulation could improve the fouling for the treatment of raw water.Besides,coagulation/UF could remove organics in each region,and organics with MW greater than 30 kDa were the most possible matters causing membrane fouling,while organics with MW less than 1 kDa were impossibly responsible for membrane fouling due to few organics removed.Therefore,organics with MW greater than 30 kDa were the major factor of membrane fouling.

关键词： fouling molecular weight distribution organics ultrafiltration

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Cake models applied to evaluate the fouling mechanism in separation of anionic polyacrylamide using modified PVDF ultrafiltration membranes

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Journal of Harbin Institute of Technology(New Series) 2012年第1期19卷 125-128页

作者：衣雪松时文歆于水利孙楠王硕孙力平 State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology State Key Laboratory of Pollution Control and Resources Reuse Tongji University Tianjin Key Laboratory of Aquatic Science and Technology Tianjin Institute of Urban Construction

In the present study,nano-sized TiO2 /Al2O3 modified PVDF membranes (MM) were fabricated and utilized for anionic polyacrylamide ( APAM) separation. The results showed that,compared with PVDF membrane (OM) ,the contact angle of MM decreases from 83. 64° to 67. 42°,which indicates the increase of the hydrophilicity of MM. The relative flux (RF) decline curve of this ultrafiltration of APAM in water with time shows an obvious two stage properties. The cake filtration models were used to predict the performance of different time over the complete range of filtration times. All the four cake models could simulate this UF process to a certain extent,and the suitability of the two kinds of membranes was: cake filtration > intermediate pore blocking > standard pore blocking > complete pore blocking models. However,they became more and more unsuited to this process with time extending. Surface and cross-sectional morphology of membrane was investigated by SEM to make an advanced certificate of this UF mechanism.

关键词： cake models APAM nano-particles Al2O3 /TiO2 PVDF ultrafiltration membranes fouling mechanism

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Preparation and characterization of PVDF-PFSA flat sheet ultrafiltration membranes

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Frontiers of Chemical Science and Engineering 2012年第3期6卷 301-310页

作者： Jiquan MA Junhong ZHAO Zhongbin REN Lei LI School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Sinopec International Petroleum Exploration and Production Corporation Sudan Branch Beijing 100029China

High performance polyvinylidene fluoride （PVDF） flat sheet ultrafiltration （UF） membranes have been prepared by an immersion precipitation phase inversion method using perfluorosulfonic acid （PFSA） as a pore former and as a hydrophilic component of the membranes and polyethylene glycol （Mw = 400）（PEG400） as a pore forming agent. The effects of the presence of PEG and the concentration of the PFSA on the phase separation of the casting solutions and on the morphologies and performance of UF membranes including their porosity, water flux, rejection of bovine serum albumin （BSA） protein, and anti-fouling property were investigated. Phase diagrams, viscosities and the phase separations upon exposure to water vapor showed that both PEG400 and PFSA promoted demixing of the casting solution. Scanning electron microscopy measurements showed that the PVDF-PFSA blend membranes had more macropores and finger-like structures than the native PVDF membranes. The PVDF-PFSA membrane （5 wt-% PEG400 ＋ 5 wt-% PFSA） had a pure water flux of 141.7L/m2.h, a BSA rejection of 90.1% and a relative pure water flux reduction （RFR） of 15.28%. These properties were greatly superior to those of the native PVDF membrane （pure water flux of 5.6 L/m2. h, BSA rejection of 96.3% and RFR of 42.86%）.

关键词： polyvinylidene fluoride perfluorosulfonic acid polyethylene glycol flat sheet membrane ultrafiltration

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Preparation and characterization of asymmetric ultrafiltration membrane for effective recovery of proteases from surimi wash water

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Frontiers of Chemical Science and Engineering 2012年第2期6卷 184-191页

作者： Nora'aini ALI Fadhilati HASSAN Sofiah HAMZAH Department of Engineering Science Faculty of Science and Technology University Malaysia Terengganu 21030 Kuala Terengganu Malaysia

The wash water generated from the surimi processing industry contains a large amount of proteases which are widely used in the food and biotechnology industries. Asymmetric polysulfone and polyethersulfone ultrafiltration （PSf-UF and PES-UF） membranes with three different polymer concentrations were screened for their abilities to recover proteases from surimi wash water. In- house fabricated membranes were prepared via a simple dry/wet phase inversion technique and were characterized in terms of permeability coefficient, membrane morphol- ogy and molecular weight cut-off （MWCO）. The ability of the UF membranes to remove commercial proteases was tested at various pressures （up to 10 bars）. The membrane with the best performance, 15 wt-% PSf-UF, was further tested with actual surimi wash water. The effect of the pH of the feed solution （4 to 8） in the pre-treatment stage was also evaluated to recover the highest amount of proteases. The highest retention of protease was 96% with a flux of 25.6 L/（mZ.h） which was achieved with the 15 wt-% PSf- UF membrane.

关键词： membrane ultrafiltration proteases surimi wash water

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