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Frontiers of Chemical Science and Engineering 2010年第3期4卷 360-366页

作者： Jianxian ZENG Junfeng LIU Niandong HUANG College of Chemistry and Chemical Engineering Hunan University of Science and TechnologyXiangtan 411201China

The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid)sodium salt(PAASS).Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process.The kinetics of complexation reaction was studied for PAASS with Co^(2+).Results showed that,under a large excess of PAASS,it takes 65,55 and 40 min at pH 5,6 and 7,respectively,to get the equilibrium of complexation.The reaction kinetics can be described by a pseudo-first-order equation.Then,the effects of various parameters on the extraction of Co^(2+)were examined in detail.Results indicated that loading ratio,pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R.Furthermore,a concentration experiment was carried out at pH 7.With increasing volume concentration factor,membrane flux declines slowly,and R value is always about 1.The concentrated retentate was used further for a decomplexation experiment.The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%.After the decomplexation step,a diafiltration experiment was performed at pH 2.5.Cobalt ions can be extracted satisfactorily from the retentate,and a purified PAASS is obtained.

关键词： cobaltion poly(acrylic acid)sodium salt complexation ultrafiltration extraction

Dissolved Air Flotation in Combination with ultrafiltration Membrane Modules in Surface Water Treatment

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Journal of Harbin Institute of Technology(New Series) 2017年第3期24卷 23-30页

作者： Yulong Shi Jun Ma Daoji Wu Qin Pan National Engineering Research Center of Urban Water Resources Harbin Institute of Technology Harbin 150090 China State Key Lab of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090 China School of Municipal and Environmental Engineering Shandong Jianzhu University Jinan 250010 China Huainan Capital Water Co. Ltd. Huainan 232003 Anhui China

The primary purpose of this research is to evaluate the feasibility of dissolved air flotation(DAF) as pretreatment process for membrane modules in river water treatment.The performances of DAF in combination with an up-flow membrane biofilter(MBF) and a hollow-fiber ultrafiltration membrane(UFM) were investigated respectively.Removal efficiency of ultraviolet absorbance at 254 nm(UV254),ammonia nitrogen(NH3-N),particle counts and microbial index were measured for both systems.Results showed that DAF was a robust pretreatment process for floc particles separation despite of raw water quality fluctuations.For DAFUFM system,the monitoring data indicated bacteria breeding,nitrite accumulation in membrane vessel and the ammonia concentration of permeate water even exceeded regulatory limits.By contrast,DAF-MBF system was established via the introduction of multilayer filter media between DAF and curtain type ultrafiltration membrane.In MBF,the matured biological activated carbon(BAC) and zeolite particles guaranteed the efficient removal of both organic matters and ammonia.Moreover,the high dissolved oxygen levels in DAF effluent significantly improved bio-adsorption and degradation of pollutants in MBF.The retention of microorganisms by the membrane not only ensured a high concentration of biomass,but also eliminated the risk of microbes leaking out from MBF.In addition,compared with UFM,the curtain membrane exhibited obviously slower fouling development.These results suggested that the DAF-MBF system was more suitable for purifying raw waters seriously polluted by dissolved contaminants.

关键词： dissolved air flotation ultrafiltration particle activated carbon zeolite membrane biofouling

PROTEIN SEPARATION USING ultrafiltration-AN EXAMPLE OF MULTI-SCALE COMPLEX SYSTEMS

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China Particuology 2005年第6期3卷 343-348页

作者： Zhanfeng Cui Department of Engineering Science University of Oxford Parks Road Oxford OX1 3P J UK

In this mini-review, the complexity of protein fractionation using ultrafiltration is discussed. The coupling of the system hydrodynamics, boundary Layer transport, membrane permeation, electrostatic and hydrophobic interactions and its effects on protein transmission and membrane selectivity are analysed. Although ultrafiltration is promising for larger scale protein purification and also with outstanding advantages both technically and economically, much needs to be done to derive the general guidance for membrane selection, process design and system operation. With fine tuning of operational and physiochemical conditions, the process can be greatly improved in terms of process productivity and protein purity. A coupled multi-scale approach might provide a way forward to analyse this complex system and improve the confidence in applying such a promising technology and predictability of the outcome.

关键词： protein purification protein fractionation ultrafiltration membrane separation multi-scale analysis

Electrochemical reduction of Cr(Ⅵ)in the presence of sodium alginate and its application in water purification

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Journal of Environmental Sciences 2021年第3期33卷 304-312页

作者： Bryan Butter Paola Santander Guadalupe del CPizarro Diego POyarzún Federico Tasca Julio Sánchez Facultad de Química y Biología Universidad de Santiago de ChileUSACHCasilla 40Correo 33SantiagoChile Departamento de Química Universidad Tecnológica MetropolitanaJ.P.Alessandri 1242SantiagoChile Laboratorio de Nanotecnología Recursos Naturales y Sistemas ComplejosFacultad de Ciencias NaturalesUniversidad de AtacamaCopayapu 485CopiapóChile

Chromium(Cr)is used in many manufacturing processes,and its release into natural waters is a major environmental problem today.Low concentrations of Cr(Ⅵ)are toxic to human health and living organisms due to the carcinogenic and mutagenic nature of this mineral.This work examined the conversion of Cr(Ⅵ)to Cr(Ⅲ)via electrochemical reduction using gold electrode in an acidic sodium alginate(SA)solution and subsequent removal of the produced Cr(Ⅲ)-SA by the polymer-enhanced ultrafiltration(PEUF)technique.A solution of SA in nitric acid was used both as an electrolytic medium during the voltammetric measurements and bulk electrolysis and as an extracting agent during the PEUF technique.The electroanalysis of Cr(Ⅵ)was performed by linear sweep voltammetry in the presence of acidic SA solution to study its voltammetric behavior as a function of the Cr(Ⅵ)concentration,pH,presence of Cr(Ⅲ),SA concentration and scan rate.In addition,the quantitative reduction of Cr(Ⅵ)to Cr(Ⅲ)was studied through the bulk electrolysis technique.The results showed efficient reduction with well-defined peaks at approximately 0.3 V vs.Ag/AgCl,using a gold working electrode.As the pH increased,the reduction signal strongly decreased until its disappearance.The optimum SA concentration was 10 mmol/L,and it was observed that the presence of Cr(Ⅲ)did not interfere in the Cr(Ⅵ)electroanalysis.Through the quantitative reduction by bulk electrolysis in the presence of acidic SA solution,it was possible to reduce all Cr(Ⅵ)to Cr(Ⅲ)followed by its removal via PEUF.

关键词： Alginate solution Chromium Electroanalytical chemistry ultrafiltration Water purification

Enrichment and immobilization of macromolecular analytes on a porous membrane utilizing permeation drag

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Journal of Pharmaceutical Analysis 2018年第3期8卷 187-193页

作者： Pedram Madadkar Rahul Sadavarte Raja Ghosh Department of Chemical Engineering Mc Master University

Enrichment and immobilization of analytes by chemical bonding or physical adsorption is typically the first step in many commonly used analytical techniques. In this paper, we discuss a permeation drag based technique as an alternative approach for carrying out location-specific immobilization of macro- molecular analytes. Fluorescein isothiocyanate （FITC） labeled macromolecules and their complexes were enriched near the surface of ultrafiltration membranes and detected by direct visual observation and fluorescence imaging. The level of macromolecule enrichment at the immobilization sites could be controlled by manipulating the filtration rate and thereby the magnitude of permeation drag. Higher enrichment as indicated by higher fluorescence intensity was observed at higher filtration rates. Also, larger macromolecules were more easily enriched. The feasibility of using this technique for detecting immunocomplexes was demonstrated by carrying out experiments with FITC labeled bovine serum al- bumin （FITC-BSA） and its corresponding antibody. This permeation drag based enrichment technique could potentially be developed further to suit a range of analytical applications involving more sophis- ticated detection methods.

关键词： Macromolecule Enrichment Immobilization Concentration polarization Permeation draglmmunoassay Membrane ultrafiltration

Membrane fouling reduction through electrochemically regulating flocs aggregation in an electro-coagulation membrane reactor

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Journal of Environmental Sciences 2019年第9期31卷 144-151页

作者： Kai Zhao Jingqiu Sun Chengzhi Hu Jiuhui Qu State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

Coupling coagulation and applied electric field is an efficient method to regulate cake layer porosity and hydrophilicity for alleviating ultrafiltration membrane(UF) fouling. However,the Al/Fe flocs aggregation behavior are induced from electric field and determine the cake layer structure, which has not been studied comparatively yet. Herein, the anti-fouling performance in an efficient electro-coagulation membrane reactor(ECMR, in which UF membrane modules are placed between electrodes) was investigated with Al/Fe anode and various electrochemical parameters from the viewpoint of regulating flocs aggregation.Both the cake layers formed from Al and Fe flocs under an electric field were more porous and hydrophilic in comparison with that formed without electric fields, resulting in an enhanced water flux under higher electric field strength. Comparing with Fe flocs, Al flocs had a faster growth rate and larger size, facilitating membrane pore block resistant, which was more pronounced in a higher current density. Furthermore, the cake layer formed from Al flocs was more porous than that formed from Fe flocs. Therefore, the anti-fouling performance of ECMR with Al anode was superior to that of ECMR with Fe anode. When the electric field strength increased from 0 to 10 V/cm, the normalized specific flux was improved from 71.2% to 89.4% for ECMR(Al) and from 48.1% to 70.1% for ECMR(Fe) at 30 min.

关键词： Electrocoagulation ultrafiltration Membrane fouling Electric field Cake layer

Removal characteristics of microplastics by Fe-based coagulants during drinking water treatment

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Journal of Environmental Sciences 2019年第4期31卷 267-275页

作者： Baiwen Ma Wenjing Xue Yanyan Ding Chengzhi Hu Huijuan Liu Jiuhui Qu Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of Sciences College of Environment and Safety Engineering Qingdao University of Science and Technology University of Chinese Academy of Sciences School of Environment State Key Joint Laboratory of Environment Simulation and Pollution ControlTsinghua University Research Center for Water Quality and Ecology Tsinghua University

Microplastics have caused great concern worldwide recently due to their ubiquitous presence within the marine environment. Up to now, most attention has been paid to their sources,distributions, measurement methods, and especially their eco-toxicological effects. With microplastics being increasingly detected in freshwater, it is urgently necessary to evaluate their behaviors during coagulation and ultrafiltration(UF) processes. Herein, the removal behavior of polyethylene(PE), which is easily suspended in water and is the main component of microplastics, was investigated with commonly used Fe-based salts. Results showed that although higher removal efficiency was induced for smaller PE particles, low PE removal efficiency(below 15%) was observed using the traditional coagulation process, and was little influenced by water characteristics. In comparison to solution pH, PAM addition played a more important role in increasing the removal efficiency, especially anionic PAM at high dosage(with efficiency up to 90.9%). The main reason was ascribed to the dense floc formation and high adsorption ability because of the positively charged Fe-based flocs under neutral conditions. For ultrafiltration, although PE particles could be completely rejected,slight membrane fouling was caused owing to their large particle size. The membrane flux decreased after coagulation; however, the membrane fouling was less severe than that induced by flocs alone due to the heterogeneous nature of the cake layer caused by PE, even at high dosages of Fe-based salts. Based on the behavior exhibited during coagulation and ultrafiltration, we believe these findings will have potential application in drinking water treatment.

关键词： Microplastics Removal FeCl3·6H2O Coagulation ultrafiltration

Cleaning method of the oil field wastewater treatment by UF process

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Journal of Environmental Sciences 2001年第3期13卷 365-367页

作者： WANG Jing rong, Xu Cheng(Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China) 中科院生态环境研究中心北京 100085

This article introduces experiments and researches of polysulphone ultrafiltration membrane's effect on oil field polluted water and approaches renewing oil field polluted water and approaches renewing of membrane's flux by different detergents and cleaning method. Good result has been achieved by doing experiments and the renewal rate of membrane is over 90%.

关键词： Detergents Membranes Oil fields ultrafiltration Water pollution

Drinking water production by uitrafiltration of Songhuajiang River with PAC adsorption

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Journal of Environmental Sciences 2007年第5期19卷 536-539页

作者： XIA Sheng-ji LIU Ya-nane LI Xing YAO Juan-juan State Key laboratory of Pollution Control and Resources Reuse Tongji University Shanghai 200092 China School of Environmental Science and Engineering Dong Hua UniversityShanghai 201620China School of Architecture and Civil Engineering Beijing University of Technology Bejing 100083 China

In recent years, membrane ultrafiltration （UF） of surface water for drinking water treatment has become a more attractive technology worldwide as a possible alternative treatment to conventional clarification. To evaluate the performance of ultrafiltration membranes for treatment of surface water in North China, a 48-m^2 low pressure hollow fiber membrane ultrafiltration pilot plant was constructed. ultrafiltration was operated in cross-flow and with powdered activated carbon （PAC） adsorption. Turbidity was almost completely removed to less than 0.2 NTU （below Chinese standard 1 NTU）. It was found that PAC addition enhanced organic matter removal. The combined process of PAC/UF allowed to 41% removal of CODMn, 46% removal of DOC and 57% decrease in UV254 absorbance. The elimination of particles, from average 12000/ml in the raw water to approximately 15/ml in the permeated, was observed. When PAC concentration was below 30 mg/L, backwashing could recovery the membrane flux with backwash interval/backwashing duration of 1/30.

关键词： surface water drinking water treatment ultrafiltration powdered activated carbon

Enhancement of Resistance to Protein Fouling of Poly(ether imide) Membrane by Surface Grafting with PEG under Organic Solvent-free Condition

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Chinese Journal of Polymer Science 2018年第10期36卷 1157-1167页

作者： Pattama Phomdum Sana Gassara Andre Deratani Watchanida Chinpa Department of Materials Science and Technology Faculty of Science Prince of Songkla University Hat-Yai Songkhla 90110 Thailand Institut Europeen des Membranes IEM UMR5635 ENSCM CNRS Univ Montpellier Montpellier France

Poly（ether imide）（PEI） membrane with enhanced antifouling property was successfully prepared in a mild and simple procedure. The virgin membrane was firstly functionalized with an aqueous solution of diamino-terminated poly（ethylene oxide） block copolymer （PEG-diamine）. Glutaraldehyde was used in a second step as a linker to chemically attach additional PEG-diamine to the primary amine groups grafted on PEI membrane surface. Immobilization of PEG segments was confirmed using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy. ultrafiltration experiments revealed that the enhancement of a PEG coverage on the membrane surface provided superior anti-protein-fouling property. Cycles of protein filtration also demonstrated that the antifouling surface was stable over time and excellent ultrafiltration performance could be maintained without the need of harsh cleansing operation.

关键词： Poly（ether imide） Surface modification Anti-protein-fouling ultrafiltration Poly（ethylene glycol）