ION VELOCITY IN SOIL SOLUTION DURING ELECTROKINETIC REMEDIATION

During the electrodecontamination of soils the pollutants' fluxes cont rol the decontamination time. Application of this technique to real ca ses necessitates some simple predictive tools to rapidly evaluate the feasibility of the method. The pollutants' fluxes depend on their conc entration and their velocity in the soil solution. In this paper our i nterest focuses on this pore velocity. A simple expression for the vel ocity 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 electrica l field applied). An adapted methodology is developed (pH control, ste ady state conditions) and applied at laboratory scale using kaolinite as a soil model and some cations as model pollutants. Experimental res ults and theoretical calculations are compared. (C) 1997 Elsevier Scie nce B.V.