Coupled Transport Processes across Clay Membranes

Coupled transport process involving passage of water and aqueous electrolytes across bentonite and kaolinite clay membranes in different cationic forms, as well as a clay humate membrane has been studied, under both isothcimal and non-isothermal conditions. Specially designed osmotic cells have been fabricated for the purpose and used. The experimental data have been fitted to formulations developed on the frame-ork of non-equilibrium thermodynamics to yield the appropriate reflection coefficient and heat of transport values for various membrane transport systems. An attempt has been made to interpret these values in terms of structural modifications in clay-sorbed water, ensuing from the clay-water interactions, as compared to the bulk water state.