Penetration of fresh water into clay saturated by an electrolyte (experiment)

Penetration of distilled water into a clay soil sample saturated by a sodium chloride solution is experimentally studied. Changes in filtration characteristics of soil due to penetration of fresh water and swelling of clay particles, as well as due to the action of an electrical field on the replacement process are quantified. It is demonstrated that electrokinetic processes play a key role at the final stage of replacement of the solution by fresh water. Reasons for the emergence of clay self-polarization potentials owing to violation of electrical equilibrium conditions are studied.