ENHANCING ELECTROKINETIC REMEDIATION OF NICKEL-CONTAMINATED SOILS UTILIZING THE APPROACHING ANODES TECHNIQUE

The soils contaminated by Ni near an electroplating factory were remedied via an enhancing electrokinetical method utilizing approaching anodes (AAs). The variations of the removal efficiency and the soil pH as a function of the treatment time were determined. The maximum Ni removal efficiency was found to be as high as 67.2% under a voltage gradient of 1 V/cm for 48 hours; in contrast to 31.5% when the conventional electrokinetic remediation with one fixed anode (FA) was employed. Several anodes were inserted as AAs in the treated soils. They were switched from the anode towards the cathode allowing for high fr ions concentrations and high redox potentials to migrate fast towards the cathode. As a result, the soil remediation is accelerated. The mechanism of Ni electromigration behavior in soils during an enhanced EK method is described as the elution in an electrokinetically driven chromatogram.