Non-equilibrium thermodynamics of electro-osmosis of water through composite clay membranes, 1. The parallel arrangement

• Published in: Journal of hydrology (Amsterdam) Vol. 25; no. 3; pp. 307 - 324
• Main Authors: Srivastava, R.C., Jain, Abhay K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.1975
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/0022-1694(75)90028-1

Electro-osmosis of water through composite clay membranes consisting of kaolinite and bentonite in parallel arrangement has been studied, and the form of the phenomenological relations for the simultaneous transport of water and electricity worked out. The phenomenological relation for the electrical flux has been found to be the usual linear and homogeneous equation, while the relationship between the water flux and the thermodynamic forces has been found to be represented by a non-linear exponential type of relationship. Relationships among the phenomenological coefficients characterizing the parallel arrangement as a whole and its constituent membrane elements have been investigated. The combination rules given by Kedem and Katchalsky have been found to be valid for the phenomenological coefficients representing the streaming current and ordinary electrical conductivity but not in the case of the other two coefficients representing the hydraulic conductivity and the electro-osmotic velocity, for which modifications in the combination rules have been suggested. Study of directional characteristics of the phenomenological coefficients has revealed the isotropic character of the composite parallel clay membrane.