Retention measurements of nanofiltration membranes with electrolyte solutions
Retention measurements of nanofiltration membranes with electrolyte solutions
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DOI：
10.1016/s0376-7388(98)00079-9
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发表时间：
1998-07-08
影响因子：
9.5
通讯作者：
Strathmann, H
中科院分区：
文献类型：
--
作者：
Peeters, JMM;Boom, JP;Strathmann, H
CaCl2、NaCl 和 Na2SO4 单盐溶液的截留测量表明，本研究中研究的商用聚合物纳滤膜的截留机制可分为两类： 1．唐南排斥似乎起着重要作用的膜。2．保留率由唐南排斥和尺寸效应共同决定的膜。在第 1 类中，发现了带正电荷和带负电荷的膜。孔径为 3 nm 的陶瓷 γ-Al2O3 超滤膜表现出与带正电荷的聚合物膜相同类型的盐保留行为。扩展的 Nernst-Planck 方程与 Donnan 平衡相结合 已用于模拟盐溶液的通量保留实验。数值计算与实验数据非常吻合，并且已经确定了固定电荷密度的可接受值。计算出的有效膜厚度高于扫描电镜观察到的有效膜厚度。 (C) 1998 Elsevier Science B.V.
Retention measurements with single salt solutions of CaCl2, NaCl and Na2SO4 revealed that the rejection mechanism of commercial polymeric nanofiltration membranes investigated in this study may be divided into two categories:1. Membranes for which Donnan exclusion seems to play an important role.2. Membranes for which retention is determined by both Donnan exclusion and size effects.In category 1 both positively and negatively charged membranes were found.Ceramic gamma-Al2O3 ultrafiltration membranes with a pore size of 3 nm showed a same type of salt retention behavior as the positively charged polymeric membranes.The extended Nernst-Planck equation in combination with the Donnan equilibrium has been used to model the flux-retention experiments for the salt solutions. The numerical calculations resulted in a good agreement with experimental data and acceptable values for the fixed charge densities have been determined. The effective membrane thicknesses calculated were higher than those observed by scanning electron microscopy. (C) 1998 Elsevier Science B.V.