Copper Removal from Kaolinite Using Enhanced Electrokinetic Soil Processing

Abstract

ABSTRACT Recently electrokinetic soil remediation has become one of the most promising soil decontamination process that has high removal efficiencies and time-effectiveness in low-permeability soils such as clay. It is a method that can remove not only ionic contaminants by electromigration but also non-polar organics by electroosmosis. The purposes of this study were to investigate the effects of pH on transport phenomena in soil while removing copper from kaolinite by electrokinetic remediation, and to examine the removal efficiencies under various experimental conditions. The results showed that electrokinetic soil remediation lead to high removal efficiency. Under a direct current density of 1.24 mA/cm2 for 4 days, 87.5% of copper was removed from kaolinite where the pH of the anode electrolyte solution was controlled at 2.5. At a higher pH of anode electrolyte solution, the removal efficiency decreased significantly. The results indicated that the copper removal efficiency was dependent on the amount of hydronium ions transported through soil, and the maximum electroosmotic flow was observed to be 6.79 cm/day. It was concluded that both electromigration and electroosmosis affected the removal efficiency of copper in soils.