Electrokinetic study on copper contaminated soils

Electrokinetic technology was conducted on three copper contaminated soils to investigate the potential use of this technology for soil remediation. Several variables, such as adsorption capacity of the soils, fractions of copper in the soils, reaction time, pH and injection of conducting solutions into the soils that may affect the removal efficiency of electrokinetic process were studied. The results showed that the electrokinetic process has the potential to remove carbonate and Fe-Mn oxides' copper in contaminated soils, which accounts for 70-85% of copper in the soils. With 8 volts of electrification for 30 days, the highest removal efficiency was found in an acidic clay soil mixed with 0.1 N of HCl conducting solution. This study suggests that the higher adsorption capacity and the lower saturated basic soils produce lower removal efficiency. In order to increase removal efficiency, injection of strong acid into the specimen seems to be a promising solution. Strong acid solutions prevent the precipitation of copper hydroxide in the specimen and support the ion desorbed from the soils, which result in increasing the removal efficiency by 40%.