Efficacy of EDTA Enhanced Electrokinetic Technique on Metal Spiked Soil

There are many remediation techniques in the current scenario which facilitate the removal of contaminants from soil and groundwater. However, techniques such as bioremediation, soil vapor extraction, soil flushing, phytoremediation, vitrification, and others have proven incapable of transporting organic and inorganic contaminants in low permeable soils. Electrokinetic treatment (EKT) is one technique that can overcome this limitation. This paper illustrates EKT studies conducted to observe the effectiveness of EDTA solution (purging solution) in different concentrations for removing heavy metals from high plastic clayey soil. The EKT was conducted on soil spiked with copper and lead ions at 500 and 1000 mg/kg concentrations. Using two perforated iron electrodes, an electric gradient of 1 V/cm was applied to the soil specimens. The EDTA as a purging solution was used at the catholyte at varying molar concentrations of 0.05, 0.1 and 1 M. EDTA as a purging solution increased the Cu2+ and Pb2+ removal efficiency by EKT in high plastic clayey soil. It was observed that 1 M EDTA solution enhanced the Cu2+ removal efficiency by 41 and 48% from the 1000 and 500 mg/kg loaded soils. Whereas higher removal efficiency of 46 and 36% was observed for Pb2+ contaminated soil for load ratios of 1000 and 500 mg/kg at 0.1 M EDTA. This study proves the effectiveness of EDTA as a purging solution in decontaminating the high plastic clayey soil spiked with Cu2+ and Pb2+ using EKT.