The Electrochemical Remediation of Pb-Contaminated Soils

The electro-remediation for soils contaminated by heavy metals has been investigated in this study. The deasibility of applying an electric field with a constant or voltage across the soil specimen for removing Pb has been examined. As the electrolytic treatment is proceeded, H⁺ and OH^- are generated at the anode and cathode, respectively, and a non-uniform pH distribution would be formed. Experimental results showed that the efficiencies of electro-treatments without buffering at the cathodic compartment were not high enough due to the pH variation across the soil specimen and the precipitation near the cathode. In order to control the pH distribution and improve the heavy-metal removal efficiency, a buffer solution was employed in the cathodic compartment. The Pb removal efficiency could attain about 85% after 32-day treatment.