Impact of electrodialytic parameters on cation migration kinetics and fouling nature of ion-exchange membranes during treatment of solutions with different magnesium/calcium ratios
Impact of electrodialytic parameters on cation migration kinetics and fouling nature of ion-exchange membranes during treatment of solutions with different magnesium/calcium ratios
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DOI：
10.1016/j.memsci.2008.08.023
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发表时间：
2008-12-01
影响因子：
9.5
通讯作者：
Bazinet, Laurent
中科院分区：
文献类型：
--
作者：
Casademont, Christophe;Farias, Monica Araya;Bazinet, Laurent
采用X射线衍射（XRD）和扫描电子显微镜（SEM）对不同Mg/Ca比（R = 0、1/20、1/10、1/5和2/5）和不同pH值（酸性、中性和碱性）的溶液进行电渗析（艾德）处理，对离子交换膜上的污染物进行表征和鉴定。在中性和碱性条件下（R = 1/5和2/5），在阴离子交换膜（AEM）浓缩液侧观察到矿物污染，在碱性条件下，在阳离子交换膜（CEM）浓缩液侧以及稀释液侧观察到矿物污染。本工作的目的是连接的形态表征和识别膜污染的电渗析参数和阳离子迁移动力学。在R >= 1/5的碱性条件下，CEM选择渗透性似乎受到严重影响。这种改变的结果是OH-通过CEM的迁移，稀释液室中的pH值增加和不同的治疗持续时间。对于Mg/Ca：1/5，在AEM浓缩物侧观察到的方解石首先是由于特定的操作条件，例如浓缩物溶液的再循环，以及在AEM界面处达到或未达到的过饱和条件和有利的pH条件。(C)2008 Elsevier B. V.保留所有权利。
During electrodialysis (ED) treatment of solutions with different Mg/Ca ratios (R = 0, 1/20, 1/10, 1/5 and 2/5) and in different pH conditions (acid, neutral and basic), foulings on ion-exchange membranes were previously characterized and identified, by the way of X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. A mineral fouling was observed in neutral and basic conditions (for R = 1/5 and 2/5) on the anion-exchange membrane (AEM) concentrate side and in basic conditions on the cation-exchange membrane (CEM) concentrate side as well as on the diluate side for R = 1/5 and 2/5. The objectives of this present work were to link the morphological characterization and identification of membrane fouling to electrodialytic parameters and cation migration kinetics. It appeared that the CEM permselectivity was severely affected in basic conditions for R >= 1/5. The consequence of this alteration was the migration of OH- through the CEM, a pH increase in the diluate compartment and different treatment durations. The calcite observed on AEM concentrate side for Mg/Ca : 1/5 would be due first to the particular operating conditions such as the recirculation of the concentrate solution, and also to the supersaturated conditions reached or not at the AEM interface and favourable pH conditions. (C) 2008 Elsevier B.V. All rights reserved.