Ion velocity in soil solution during electrokinetic remediation

During the electrodecontamination of soils the pollutants' fluxes control the decontamination time. Application of this technique to real cases necessitates some simple predictive tools to rapidly evaluate the feasibility of the method. The pollutants' fluxes depend on their concentration and their velocity in the soil solution. In this paper our interest focuses on this pore velocity. A simple expression for the velocity of cationic species in the pore solution is proposed, for a wide range of situations where electroosmosis and electromigration an the major contributing ion transport mechanisms (governed by the electrical field applied). An adapted methodology is developed (pH control, steady state conditions) and applied at laboratory scale using kaolinite as a soil model and some cations as model pollutants. Experimental results and theoretical calculations are compared. (C) 1997 Elsevier Science B.V.