Chemical and physical aspects of cleaning of organic-fouled reverse osmosis membranes
Chemical and physical aspects of cleaning of organic-fouled reverse osmosis membranes
复制标题
DOI：
10.1016/j.memsci.2005.07.035
复制
发表时间：
2006-03-15
影响因子：
9.5
通讯作者：
Elimelech, M
中科院分区：
文献类型：
--
作者：
Ang, WS;Lee, SY;Elimelech, M
系统地研究了化学和物理相互作用在清洗有机污染反渗透（RO）膜中的作用。使用实验室规模的横流测试装置，用有机污染物（海藻酸盐和天然有机物）模拟出水有机物（EfOM）和选定的清洁剂进行污染和清洁实验。在二价钙离子加速有机污染运行之后，在不同的化学和物理条件下进行了清洁实验。结果表明，金属螯合剂（EDTA）和阴离子表面活性剂（SDS）通过优化清洗过程中的化学（剂量和pH）和物理（时间、横流速度和温度）条件，能够有效地清洗污染的反渗透膜。然而，当用NaOH （pH 11）清洗时，渗透通量恢复得很差。界面力测量（AFM）进一步证实了清洗结果，证明了清洗剂对降低污垢粘附力的影响。结果表明，EDTA和SDS清洗明显降低了钙-垢相互作用引起的附着力，而NaOH清洗仍有较大的附着力。提出了两种重要的清洗机理，即清洗剂与污垢层的化学反应，以及化学剂（从本体相到污垢层）和污垢（从污垢层到本体相）的传质，可以选择高效的清洗剂和良好的清洗条件。(c) 2005 Elsevier B.V.版权所有
The role of chemical and physical interactions in cleaning of organic-fouled reverse osmosis (RO) membranes is systematically investigated. Fouling and cleaning experiments were performed with organic foulants (alginate and natural organic matter) that simulate effluent organic matter (EfOM) and selected cleaning agents using a laboratory-scale crossflow test unit. Following accelerated organic fouling runs with divalent calcium ions, cleaning experiments were performed at various chemical and physical conditions. The results showed that a metal chelating agent (EDTA) and an anionic surfactant (SDS) were able to clean the fouled RO membrane effectively by optimizing chemical (dose and pH) and physical (time, crossflow velocity, and temperature) conditions during cleaning. The permeate flux was, however, poorly recovered when cleaning was performed with NaOH (pH 11). Interfacial force measurements (by AFM) further confirmed the cleaning results, demonstrating the influence of cleaning agents on reducing the foulant-foulant adhesion force. The results showed that the adhesion force caused by calcium-induced foulant-foulant interaction was reduced significantly with EDTA and SDS cleaning, while substantial adhesion force still remained following NaOH cleaning. It is proposed that an efficient cleaning agent and favorable cleaning conditions could be selected by considering two important mechanisms: chemical reaction between cleaning agents and foulants in the fouling layer, and mass transfer of chemical agents (from the bulk phase to the fouling layer) and foulants (from the fouling layer to the bulk phase). (c) 2005 Elsevier B.V. All rights reserved.