An Approach to Electrokinetic Removal of Cr(VI) from Soil and Kaolin Samples

The present study examines electroremediation's efficiency on Cr(VI) contaminated samples. Electrokinetic experiments were performed applying a DC voltage of 30 V to a cylindrical sample of 30 cm length and 4 cm diameter, using Na2SO4 as background electrolyte solution. The first two experiments, one with kaolin and one with soil, were carried out without applying any pH adjustment in the anode or the cathode compartment, using 0.01 M Na2SO4. Further experiments were carried out increasing the electrolyte's concentration and using Mg(OH)2 to neutralize the generated acidity in the anode. The decrease in Cr(VI) concentration in the soil samples is partly taking place because of its reduction, most likely due to the presence of organic matter. This is indicated by the mass balance calculations which were based on the analyses of treated solid samples and electrolyte solutions. İn the kaolin samples electromigration is the main factor resulting in the accumulation of Cr(VI) in the anodic solution.