反洗水组分对超滤膜污染的影响  

Effect of Backwash Water Composition on UF Membrane Fouling

作　　者：陈婷婷 赵学辉[1,2] 王捷 张宏伟[1,2] CHEN Ting-ting;ZHAO Xue-hui;WANG Jie;ZHANG Hong-wei(School of Environmental and Chemical Engineering, Tianfin Polytechnic University, Tianjin 300387, China;State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387, China)

机构地区：[1]天津工业大学环境与化学工程学院,天津300387 [2]天津工业大学省部共建分离膜与膜过程国家重点实验室,天津300387

出　　处：《中国给水排水》2018年第9期85-89,共5页China Water & Wastewater

基　　金：国家自然科学基金面上资助项目(51578374);天津市高等学校科技发展基金计划项目(20140517)

摘　　要：超滤反洗如同短时间的"死端过滤",反洗水组分对超滤膜污染进程有重要影响,以腐殖酸(HA)、Na^+和Ca^(2+)模拟反洗水中的小分子有机物、一价和二价金属阳离子,将海藻酸钠(SA)作为典型污染物,通过死端过滤的方式分析了反洗水中的不同组分对PVDF超滤膜污染的影响。同时借助质量守恒定律对膜的反洗效率和反洗后污染物的去除情况进行了定量分析。结果表明,反洗水中单独存在的小分子有机物对膜污染的影响并不显著,但小分子有机物协同金属阳离子对膜污染产生了较为明显的不利影响;一方面Ca^(2+)、Na^+等阳离子能够与带负电的HA小分子吸附结合,形成尺寸较大的聚集体,导致膜内壁污染以及反洗膜孔的堵塞,从而降低反洗效率,加剧膜面污染物的积累;另一方面,通过Ca^(2+)、Na^+等阳离子的"架桥作用"与电荷屏蔽效应,强化了膜表面污染物与膜壁之间的静电吸附作用,导致了更为严重的不可逆污染。UF backwash is similar to a short-time ＂dead-end filtration＂. The composition of the backwashing water has important influences on the process of UF membrane fouling. Humic acid （ HA）, Na ＋ and Ca2＋ were applied to simulate low-molecular-weight organics, monovalent and bivalent mental cations, respectively. Sodium alginate was performed under dead-end filtration （SA） was selected as the typical contaminant. The experiment mode to investigate the effect of different backwash water composition on the PVDF UF membrane fouling. Backwash efficiency and the foulant removal after backwash were quantitatively analyzed according to the mass balance. The results showed that the effect of low-molecular-weight organics in backwash solution alone on membrane fouling were insignificant. However, subsequently reduced backwash efficiency and increased the accumulation of foulant on the membrane surface. Moreover, through the ＂bridging effect＂ and the charge shielding effect of Ca2＋ and Na＋ ions,the electrostatic interaction between the foulant and the membrane surface was enhanced, which resulted in serious irreversible fouling.

关 键 词：超滤 膜污染 反洗水组分 反洗效率 海藻酸钠 

分 类 号：TU991[建筑科学—市政工程]