蛭石改性PVDF超滤膜的污染行为模型解析  

Exploration on fouling behavior of vermiculite modified PVDF ultrafiltration membrane by membrane fouling models

作　　者：张彤 郑雯佳 王巧英[1] 吴志超[1] ZHANG Tong;ZHENG Wenjia;WANG Qiaoying;WU Zhichao(School of Environmental Science and Engineering,Shanghai Institute of Pollution Control and Ecological Safety,State Key Laboratory of Pollution Control and Resource Reuse,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学环境科学与工程学院,污染控制与资源化研究国家重点实验室,上海200092

出　　处：《环境工程学报》2023年第11期3611-3617,共7页Chinese Journal of Environmental Engineering

基　　金：上海市青年科技启明星计划资助(20QC1400300)。

摘　　要：采用蛭石纳米颗粒(Verm NPs)、盐酸多巴胺(DA)、硅烷偶联剂KH550及三(羟甲基)氨基甲烷盐酸盐对聚偏氟乙烯(PVDF)超滤膜进行表面改性,通过5种膜污染模型对1 g·L^(-1)的牛血清蛋白溶液(BSA)及含蛋白质的实际废水进行抗污染研究。结果表明:改性体系在pH=7.2~7.3的条件下,多巴胺与KH550的聚合交联及蛭石羟基化表面的配位作用可共同将蛭石纳米颗粒稳定黏附在膜表面,蛭石在膜表面的冲刷恰好可以与聚多巴胺网状物形成最优配合,形成克服渗透性和选择性的Trade-off效应的高渗透性高截留的表面改性层。改性膜的BSA污染减轻,5种膜污染模型拟合曲线的R2均从改性前的0.90~0.94降至0.75~0.79,且膜污染的形成主要发生在过滤初期。采用实际含蛋白质废水对膜进行抗污染测试,发现改性后5种膜污染模型拟合曲线的R2均较改性前降低,膜污染得到缓解。由于实际废水的复杂性,污染物在孔内部的不断吸附、在膜表面的沉积及最终形成滤饼层仍然是膜污染形成的重要因素。In this investigation,commercial polyvinylidene fluoride ultrafiltration membrane was modified by vermiculite nanoparticles,dopamine and KH550.The anti-fouling performance had been further explored according to 5 kinds of membrane fouling models by using 1 g·L^(-1)bovine serum albumin(BSA)solution and actual protein-containing wastewater.At pH 7.2~7.3,the polymerization and cross-linking of dopamine and KH550 and the coordination of vermiculite hydroxylated surface jointly stabilized the adhesion of Verm NPs to the membrane surface.Under this condition,the scouring effect of vermiculite on membrane surface exactly coordinated with the formation of polydopamine network,which led to an excellent modified layer with high permeability and rejection rate without trade-off effect.For fouling model fitting,the corresponding R~2 of pristine and modified membrane for BSA was decreased from 0.90~0.94 to 0.75~0.79,indicating the obvious fouling alleviation after modification,and membrane fouling mainly occurred at the early stage of filtration.Additionally,the R~2 of actual wastewater all decreased to a certain extent after modification,showing the significant effect on fouling mitigation.Notably,the unavoidable adsorption and blockage on membrane pores and inner channels by foulants as well as the formation of cake layer became the main factor of membrane fouling due to the complexity of actual wastewater.

关 键 词：蛭石 超滤膜 表面改性 膜污染 膜污染模型 

分 类 号：X703[环境科学与工程—环境工程]