A study of ultrafiltration membrane fouling by humic acids and flux recovery by backwashing: Experiments and modeling
A study of ultrafiltration membrane fouling by humic acids and flux recovery by backwashing: Experiments and modeling
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DOI：
10.1016/j.memsci.2005.05.009
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发表时间：
2005-12-01
影响因子：
9.5
通讯作者：
Karabelas, AJ
中科院分区：
文献类型：
--
作者：
Katsoufidou, K;Yiantsios, SG;Karabelas, AJ
超滤在水处理中的成功应用的关键问题之一是由于溶解的有机物引起的膜污染，其对生产率、产品质量和工艺成本产生负面影响。本研究的目的是有助于有机物的污染现象的理解和反冲洗技术，这是在实践中应用，以恢复膜通量的效率。污垢实验进行，在一个单一的纤维装置，使用腐殖酸溶液作为模型物质代表天然存在的有机物，他们的目的是在确定不同的污垢机制的意义和它们的可逆性程度。提出了一个新的模型，该模型考虑了所有污垢机理的同时作用，并成功地描述了实验结果。研究中考虑的一个重要参数是钙离子的浓度，它促进腐殖酸聚集并影响通量下降速率、污垢和截留的可逆性。由于内部孔隙吸附，发生相对快速的不可逆结垢，其持续很长时间。同时，随着时间的推移，孔堵塞变得重要，并且在膜上形成污垢饼。后者的影响被部分逆转的反冲洗，但它们的综合影响持续了很长一段时间，从而引起一个长期的通量下降。(c)2005 Elsevier B.V.保留所有权利。
One of the critical issues for the successful application of ultrafiltration in water treatment is membrane fouling due to dissolved organic matter, which negatively affects productivity, product quality, and process costs. The aim of the present study is to contribute to the understanding of fouling phenomena by organic matter and the efficiency of the backwashing technique, which is applied in practice to restore membrane flux. Fouling experiments are carried out, in a single fiber apparatus, using humic acid solutions as model substances representative of naturally occurring organic matter; they are aimed at identifying the significance of distinct fouling mechanisms and their degree of reversibility. A new model is presented which takes into account the simultaneous action of all fouling mechanisms and describes the experimental results successfully. An important parameter considered in the study is the concentration of calcium ions, which promote humic acid aggregation and influence the rate of flux decline, the reversibility of fouling and rejection. A relatively rapid irreversible fouling takes place due to internal pore adsorption, which persists for a long time. In parallel, with time, pore blocking becomes important and a fouling cake develops on the membranes. The effects of the latter are partly reversed by backwashing, but their combined influence persists over a long time giving rise to a prolonged flux decline. (c) 2005 Elsevier B.V. All rights reserved.