Effect of coagulation mechanism on membrane permeability in coagulation-assisted microfiltration for spent filter backwash water recycling
Effect of coagulation mechanism on membrane permeability in coagulation-assisted microfiltration for spent filter backwash water recycling
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DOI：
10.1016/j.colsurfa.2011.01.054
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发表时间：
2011-03-20
影响因子：
5.2
通讯作者：
Zhao, Bingqing
中科院分区：
文献类型：
--
作者：
Huang, Chihpin;Lin, Jr-Lin;Zhao, Bingqing
混凝是膜过滤回用废滤池反冲洗水的一种有效的前处理工艺。为了优化SFBW回用混凝/过滤工艺的运行，了解混凝机理在膜过滤中的关键作用是很重要的。在本研究中，SFBW样品用聚合氯化铝(PACI)混凝，然后进行死端微滤(MF)，测定了平均渗透通量和渗透质量。结果表明，预凝处理改善了膜通量的下降，其改善程度与混凝机理密切相关。沉淀电荷中和(PCN)混凝效果最好，其次是电荷中和和扫絮凝。对滤饼性能的仔细研究表明，滤饼阻力(R-c)的降低是由于不同的混凝机理造成的。PCN诱导的较小的絮体更致密、更坚固，形成的可压缩滤饼较少，有利于膜过滤，而结构较疏松、较弱的较大絮体形成的可压缩滤饼较多，膜过滤速度较慢。混凝机制还控制着SFBW絮体的粒度分布，这与后续的滤饼可压缩性以及膜过滤中的膜透过率密切相关。(C)2011爱思唯尔B.V.保留所有权利。
Coagulation is an effective pre-treatment process in membrane filtration for recycling spent filter backwash water (SFBW). To optimize the operation of the coagulation/filtration process for SFBW recycling, it is important to understand the critical role of coagulation mechanism on membrane filtration. In this study, SFBW samples were coagulated with polyaluminum chloride (PACI), followed by a dead-end micro-filtration (MF), and the mean permeate flux and permeate quality were determined. The results showed that pre-coagulation improved the flux decline and the degree of the improvement was closely related to coagulation mechanisms. The permeate flux was enhanced most effectively by precipitation charge neutralization (PCN) coagulation, followed by charge neutralization and then sweep flocculation. Close examination of cake properties indicated that the reduced cake resistance (R-c) was subjected to the coagulated SFBW flocs in response to different coagulation mechanism. Smaller flocs, induced by PCN, were more compact and stronger, forming less compressible cake, which facilitated membrane filtration, while slower membrane filtration was observed when more compressible cake formed from larger flocs of looser and weaker structure. Coagulation mechanism also governed the size distribution of SFBW floc, which is strongly related to the subsequent cake compressibility as well as membrane permeability in membrane filtration. (C) 2011 Elsevier B.V. All rights reserved.