超滤膜直接过滤地表水试验

采用截留相对分子质量为50000的国产聚丙烯腈中空纤维超滤膜,进行地表水直接过滤试验。采用浊度为5 NTU和15NTU的原水进行试验,当膜的特性通量趋于稳定时,其值分别下降到初始值的40%和42%,结果表明在相同操作条件下,浊度的高低与膜污染程度的轻重正相关,已污染的膜经水力清洗和化学清洗后膜的特性通量恢复率达到98%,清洗效果比较理想。     

陶瓷超滤膜处理煤矿矿井水的中试研究

为解决煤矿矿井水水量和水质波动大而导致浸没式超滤膜产水量低,易污堵和难清洗的问题,开展了陶瓷超滤膜在煤矿矿井水处理系统中的中试研究。结果表明,在超滤进水投加13~15 mg/L聚合氯化铝的条件下,即使进水浊度在数小时内跃升至100 NTU,陶瓷超滤膜均可在260 L/(m2·h)的目标运行通量和315 L/(m2·h)的挑战运行通量下稳定运行。产水浊度稳定<0.1 NTU,优于后续纳滤系统进水要求。     

Preparation of soluble polyimides and ultrafiltration membrane performances

Various soluble polyimides with bis[4‐(3‐aminophenoxy)phenyl]sulfone and three kinds of dianhydrides were prepared in a polar N‐methyl‐2‐pyrrolidone solvent by the traditional chemical two‐step method. All the polymers synthesized had good solubilities in polar solvents and excellent thermal properties. Wide‐angle X‐ray diffraction studies showed that all polyimides were amorphous. Polyimide ultrafiltration asymmetric membranes were successfully prepared by the traditional phase‐inversion method. The cross sections of the polyimide ultrafiltration membranes showed a very thin surface layer and a porous sublayer. The pure water flux was very high and the solute rejection rate at poly(ethylene glycol) of MW 20,000 was above 90%. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1–9, 2000     

Synthesis and characterization of soluble polyimides and its ultrafiltration membrane performances

Soluble polyimides were synthesized and characterized from two diamines and four dianhydrides by the two- and the one-step method. Most of the polyimides could be soluble by one-step method except α,α′-bis(4-aminophenyl)-1,4-diisopropyl benzene/3,3′,4,4′-benzophenonetetracarboxylic dianhydride system in limited organic solvents. Glass transition temperatures ranged from 186 to 233°C and crystalline melt temperatures were not observed. All the soluble polyimides showed good thermal, mechanical, and electrical properties. The polyimides did not have crystalline structure and limited solubilities. The effective solvent had a medium dispersion component associated with weak polar and hydrogen components. The polymer from one-step polymerization had a narrower molecular weight distribution than the two-step method. Polyimide synthesized with 4,4′-oxydiphthalic anhydride and bis[4-(3-aminophenoxy)phenyl]sulfone by two-step method could only be prepared by the typical phase inversion method. Other membranes except this polyimide membrane could not be prepared by the typical phase-inversion method because of poor solubility about polar solvents. The flux of this ultrafiltration membrane was very high, and this membrane could especially retain polymer having a molecular weight 20,000 to above 90%. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 907–918, 1999     

金属-聚乙烯醇-二醋酸纤维素共混复合亲水超滤膜的制备

在大孔径金属纤维毡上制备了金属-聚乙烯醇-二醋酸纤维素(金属-PVA-CA)共混复合超滤膜及金属-NaCl改性PVA-CA共混复合超滤膜。该复合超滤膜在操作压力为0.25-0.45 MPa,处理质量浓度为1000 mg/L的含油乳化液,可获得40-70 L／(m2·h)的透液通量,COD截留在90％以上。研究还表明金属-NaCl改性PVA-CA共混复合超滤膜的综合性能略优于金属-PVA-CA共混复合超滤膜。     

用浸没式超滤膜深度回用污水

通过中试试验,研究了ZeeWeed(R) 500d浸没式超滤膜的反洗条件对跨膜压差的影响,确定了最佳反洗时间及水量,考察了ZeeWeed(R) 500d浸没式超滤膜对浊度、有机物的去除效果.     

自来水深度处理超滤膜的选择

试验设计、运行了聚砜中空纤维超滤(UF)膜,直接将未经预处理的某自来水管网输出水,处理成优质供水。结果表明,随着UF膜的切割分子量从0.6万增大到5万,产水量提高,对主要水质指标的去除率下降,净化水的水质优良,即使原水的水质突然恶化,UF膜能有效地将被严重污染的高浊度和色度的异常自来水转化成为符合饮用水水质指标的卫生洁净水。     

多通道TiO_2超滤膜的制备及其在印染废水中的应用

以多通道α-Al2O3陶瓷微滤膜为支撑体,采用溶胶凝胶法制备完整TiO2超滤膜。通过扫描电镜(SEM)表征膜的形貌,采用错流过滤方式考察膜的纯水通量、截留相对分子质量及分离性能。结果表明:制备的多通道TiO2超滤膜,其膜层表面完整,无裂缝、针孔等缺陷且厚度均匀,纯水通量为1.08×10-3L/(m2.h.Pa),截留相对分子质量为9 000。对直接黑OB染料及退浆废水中聚乙烯醇(PVA)的截留率均达到99%以上,截留效果显著。     

水中天然有机物对超滤膜污染研究

对超滤膜受天然有机物污染的特性进行研究,同时考查无机矿物质成分对污染的协同影响。采用PES平板膜进行膜污染试验,模拟地表水研究腐殖酸以及钙离子的影响并进行了化学清洗试验。研究结果表明,在pH值为7.8,腐殖酸质量浓度为15 mg/L,操作压力0.1 MPa下,当钙离子浓度为4 mmol/L时,膜污染最为严重,10 min后膜通量降到起始膜通量的60%以下。先用0.1 mol/L的NaOH,再用0.5%的盐酸清洗后,膜通量可恢复至起始膜通量的98%。     

超滤膜技术概述

当今社会,超滤作为一种新型膜分离技术,应用的领域十分广泛,而且也获得了良好的效果。本文首先介绍了超滤技术的原理、四大有机高分子膜材料和相转化制膜中常用的浸没沉淀法和溶剂蒸发法,然后简述了超滤膜的优点、四大领域的应用、三大污染物质及防治措施,并把超滤膜技术多年后的研究方向和未来前景总结出来。指出超滤膜具有在水处理净化、食品提纯和中药分离等方面的诸多优势,接下来在广泛总结颗粒物、有机物和微生物污染的基础上,通过针对性的污染类别,遴选出高效的处理措施,并且能够显著提升超滤膜的抗菌抗污染性能,从而为超滤膜发展和实践运用提供可能。文中提出：今后研究的重点将是制备高性能、低成本、绿色化的超滤膜,并与其他膜分离技术协同作用于生产生活。     

聚砜/聚苯胺-嵌段式聚醚Pluronic F127复合超滤膜的制备及性能

选用具有不同改性机理的嵌段式聚醚Pluronic F127与聚苯胺(PANI)纳米纤维共同作为添加剂共混改性聚砜(PSf)超滤膜,利用浸没沉淀相转化法制备出PSf/PANI-F127复合超滤膜。考察、比较并分析两种改性材料同时存在对膜结构和膜性能的影响。膜结构通过傅里叶衰减全反射红外(ATR-FTIR)、X射线光电子能谱(XPS)、X射线能量色散谱(EDS)、扫描电镜(SEM)和接触角等测试表征。膜性能通过纯水通量、截留率、抗污染性能以及添加剂稳定性结果进行评价。实验结果表明,Pluronic F127的加入可以更有效地提高膜表面亲水性,而PANI纳米纤维的加入则可以使膜孔隙率增大、表面孔径尺寸降低、皮层变薄。实验进一步发现,两种添加剂在改善膜结构与性能上起协同作用。PANI-F127一方面提高了膜纯水通量与抗污染性能,另一方面克服了单独使用Pluronic F127时添加量大、截留率低、添加剂易流失的缺点。     

温敏性PVDF/PGS-g-PNIPAM纳米复合超滤膜的制备和性能

通过化学接枝法将聚(N-异丙基丙烯酰胺)(PNIPAM)接枝聚合在凹凸棒石(PGS)纳米纤维表面,制备了系列接枝率的温敏性PGS-g-PNIPAM纳米颗粒,将其与聚偏氟乙烯(PVDF)共混制备温敏性纳米复合超滤膜,深入研究PNIPAM接枝率对膜结构和性能的影响。结果表明,凹凸棒石表面PNIPAM接枝率随溶液中NIPAM单体浓度增大而增加;PGS-g-PNIPAM使复合膜中PVDF晶核变小,数目增多,膜更为疏松多孔,PVDF/PGS-g-PNIPAM膜的平均孔径在20 nm左右,膜的平均孔径和最大孔径均随凹凸棒石表面PNIPAM接枝率的增加而增大;PVDF/PGS-g-PNIPAM膜具有温敏性,温敏开关系数随PNIPAM接枝率的增加先增强后减弱,当接枝率为21.33%时膜温敏开关系数最大,达到1.51,膜渗透通量也最大,对牛血清白蛋白具有良好的截留和抗污染性能。     

原位合成法制备高通量聚砜超滤膜及其性能研究

以聚砜（PSF）为原料,N,N‐二甲基甲酰胺（DMF）为溶剂,4,4'-二氨基二苯砜（DDS）和均苯四甲酸二酐（PMDA）为添加物,在聚砜铸膜液中“原位合成”聚酰胺酸（PAA）,采用浸没沉淀相转化法制备高水通量PSF超滤膜。使用傅里叶变换红外光谱仪（ATR-FTIR）和X射线光电子能谱分析（XPS）对膜表面化学组成进行分析,结果表明成功在膜表面引入PAA。膜的荷电性、水接触角、保湿性和水通量等性能测试表明,改性膜具有良好的保湿性和水渗透性。在0.1 MPa的运行压力下,改性膜的纯水通量和牛血清白蛋白（BSA）截留率均高于纯PSF超滤膜,纯水通量从221.39 L/(m²·h)增加至406.57 L/(m²·h),截留率从75.75%增加到96.14%;在0.01~0.1 MPa的运行压力范围内,改性膜水通量均高于纯PSF超滤膜。。     

Preparation and characterization of PVDF-PFSA flat sheet ultrafiltration membranes

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 (M_w = 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 141.7 L/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%).     

超滤膜在饮用水处理中临界通量的影响因素研究

超滤膜在临界通量以下过滤可不产生膜污染或产生极轻的膜污染,针对超滤膜在饮用水处理中的临界通量的影响因素,系统考察曝气、过滤方式和混凝沉淀预处理等对浸没式超滤膜处理松花江水临界通量的影响.结果表明,曝气强度达到10 m3/(m2·h),连续曝气可将超滤膜的临界通量提高5 L/(m2·h),曝气强度达到40 m3/(m2·...     

Polyurethane and carboxylated polysulfone blend ultrafiltration membranes. I. Preparation and characterization

Polysulfone was functionalized by carboxylation and blended with polyurethane (ether type). Blend membranes were prepared in the presence and absence of the additive poly(ethylene glycol) 600 and subjected to ultrafiltration characterizations such as compaction, pure water flux, water content, and hydraulic resistance. Morphological studies of the membranes were performed with scanning electron microscopy. The effects of the polymer composition and additive concentrations on the above parameters were analyzed and the results compared. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1307–1315, 2005     

填充活性炭的壳聚糖复合超滤膜的研究

本文用活性炭填充制备了共混的改性壳聚糖复合超滤膜,考察了活性炭和壳聚糖对酸性红B染料的静态吸附,并研究了成膜材料、活性炭在壳聚糖溶液中的分散方式、交联剂等对膜性能的影响。结果表明,活性炭壳聚糖具有协同脱色效果,在本实验条件下制得的共混膜具有良好的分离性能和干、湿态下的抗张强度。     

Comparative analysis for fouling characteristics of river water,secondary effluent,and humic acid solution in ceramic membrane ultrafiltration

Ceramic membrane ultrafiltration experiments were performed with 7-channel tubular membrane (molecular weight cutoff = 300 kD) at a constant transmembrane pressure and crossflow rate under recirculation mode. In the experiments, the fouling characteristics of river water (RW, dissolved organic carbon (DOC) = 3.4 mg/L) were compared with humic acid solution (HA1, DOC = 3.7 mg/L). Also, the fouling behaviors of secondary effluent (SE, DOC = 7.9 mg/L) were compared with HA2 (DOC = 8.5 mg/L). Fluorescence excitation-emission matrix, modified Hermia’s model, and resistance-in-series model were used to analyze the fouling characteristics. Results demonstrated that RW and SE could cause ceramic membrane fouling more rapidly due to their hydrophilic organic compositions in comparison with hydrophobic HA.     

Cellulose acetate and sulfonated polysulfone blend ultrafiltration membranes. I. Preparation and characterization

Modification of polymeric membrane materials by incorporation of hydrophilicity results in membranes with low fouling behavior and high flux. Hence, Polysulfone was functionalized by sulfonation and ultrafiltration membranes were prepared based on sulfonated polysulfone and cellulose acetate in various blend compositions. Polyethyleneglycol 600 was employed as a nonsolvent additive in various concentrations to the casting solution to improve the ultrafiltration performance of the resulting membranes. The total polymer concentration, cellulose acetate, and sulfonated polysulfone polymer blend composition, additive concentration, and its compatibility with polymer blends were optimized. The membranes prepared were characterized in terms of compaction, pure water flux, membrane resistance, and water content. The compaction takes place within 3–4 h for all the membranes. The pure water flux is determined largely by the composition of sulfonated polysulfone and concentration of additive. Membrane resistance is inversely proportional to pure water flux, and water content is proportional to pure water flux for all the membranes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1749–1761, 2002     

磺甲基化聚砜超滤膜的制备及在脱毛废液中的应用

以羟甲基磺酸钠为磺化剂,对聚砜超滤膜进行磺甲基化亲水化改性,最佳改性配比为n(HOCH2SO3Na)∶n(PSF)=1.5∶1,pH=8.0;在0.085 MPa、25℃下将改性聚砜超滤膜和聚砜膜分别用于工业脱毛废水的分离处理,并对比了废液处理前后的COD、灰分、硫化物、悬浮物、pH和色度等。结果表明,改性膜处理后废水的色度、悬浮物都得到有效去除,对废水中COD、硫化物的截留率分别达到了94%、71%以上。