Unraveling flux behavior of superhydrophilic loose nanofiltration membranes during textile wastewater treatment
Unraveling flux behavior of superhydrophilic loose nanofiltration membranes during textile wastewater treatment
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DOI：
10.1016/j.memsci.2015.07.018
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发表时间：
2015-11-01
影响因子：
9.5
通讯作者：
Van der Bruggen, Bart
中科院分区：
文献类型：
--
作者：
Lin, Jiuyang;Tang, Chuyang Y.;Van der Bruggen, Bart
松散纳滤（NF）膜可以有效地处理纺织废水，在高染料保留率和高盐渗透性的前提下，为资源回收（即染料净化和盐回用）提供了一条有吸引力的途径。然而，鉴于膜污染的实际应用，膜污染问题必须得到充分的解决。本研究采用超亲水性松散NF膜（Sepro NF 6和nf2a， culture）处理纺织废水。采用含染料和NaCl的合成溶液作为纳滤装置的进料流，发现饼增强的浓度极化和染料饼层的形成两个因素显著地降低了纳滤膜的通量，并产生协同效应。从实际应用的角度出发，对染料/盐二元混合物的滤除表明，滤饼增强的浓度极化是低膜通量的主要原因。随着滤滤的继续进行，滤饼强化的浓度极化随着饲料中盐浓度的降低而得到缓解。在随后的浓缩后过程中，染料饼层的形成略微损害了膜通量，但由于饲料中残留的盐量很少，因此饼增强浓度极化的负面影响可以忽略不计。(C) 2015 Elsevier B.V.版权所有
Loose nanofiltration (NF) membranes can be used to treat textile wastewater effectively, providing an attracted avenue for resource recovery (i.e., dye purification and salt reuse) at the premise of the integration of high dye retention and salt permeation. However, the issue of membrane fouling has to be adequately addressed in view of its practical application. In this study, superhydrophilic loose NF membranes (Sepro NF 6 and NF 2A, Ultura) were applied for textile wastewater treatment. Synthetic solutions containing dyes and NaCl were used as the feed stream of a NF unit It was found that two factors, namely cake-enhanced concentration polarization and the formation of a dye cake layer, dramatically deteriorated the flux of NF membranes with a synergic effect. In viewpoint of realistic application, diafiltration of a binary dye/salt mixture indicates that cake enhanced concentration polarization plays a dominant role for the low membrane flux. As the diafiltration continued, cake enhanced concentration polarization was alleviated with a decreasing concentration of salt in the feed. At the subsequent post concentration procedure, the formation of a dye cake layer slightly compromised the membrane flux, but the negative impact of cake enhanced concentration polarization was negligible due to the small quantity of salt remained in the feed. (C) 2015 Elsevier B.V. All rights reserved.