Fouling of reverse osmosis membranes using electrical impedance spectroscopy: Measurements and simulations
Fouling of reverse osmosis membranes using electrical impedance spectroscopy: Measurements and simulations
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DOI：
10.1016/j.desal.2007.10.066
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发表时间：
2009-01
期刊：
影响因子：
9.9
通讯作者：
J. Kavanagh;S. Hussain;T. Chilcott;H. Coster
中科院分区：
文献类型：
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作者：
J. Kavanagh;S. Hussain;T. Chilcott;H. Coster
在高回收率下使用现代高通量反渗透膜和低盐度进料，使得在实践中通过通量下降来测量结垢变得困难。结垢的早期检测非常重要，因为结垢的发生发生在临界通量时，而这很难先验预测。这里提出了另一种方法，测量膜的电性能。使用 INPHAZE™ 电阻抗分光镜在 10−1 至 105Hz 的频率范围内测量反渗透膜的污垢。当反渗透膜被少量沉淀的二价盐污染时，电导和阻抗都表现出巨大的变化。根据这些实验结果，确定了反渗透膜系统的电特性。本文采用了之前工作中确定的电特性，并对海水淡化过程的第一阶段和第二阶段的电特性进行了建模。在频率低于 100 Hz 时，膜皮层的电导率会随着结垢而显着降低。这种方法对于膜污染的在线测量和膜过滤系统的更有效运行具有巨大的潜力。
The use of modern high flux reverse osmosis membranes with low salinity feeds at high recovery rates, makes the measurement of fouling by flux decline difficult in practice. Early detection of fouling is important, because the onset of fouling occurs at a critical flux which is difficult to predict a priori. An alternative method, measuring the electrical properties of the membrane is proposed here. The fouling of a reverse osmosis membrane was measured with an INPHAZE™ Electrical Impedance Spectroscope from frequencies of 10−1to 105Hz. Both the conductance and impedance showed dramatic changes when the reverse osmosis membrane was fouled by a small amount of precipitated divalent salts. From these experimental results, electrical properties of the reverse osmosis membrane system were determined. This paper takes electrical properties determined in previous work and models the electrical properties of the first and second stages of a sea water desalination process. The decrease in the electrical conductivity of the membrane skin layer, which would accompany fouling, is significant at frequencies below 100 Hz. Such a method has great potential for online measurement of membrane fouling and more effective operation of membrane filtration systems.