Simultaneous Application of Electrokinetic and Washing Solvents for the Decontamination of Zn and Pb from tailings of Angouran lead and Zinc Mine

Mining activities have led to the accumulation of large quantities of mineral tailings containing potentially hazardous metals, contaminating the surrounding soil. This study investigated the effectiveness of electrokinetic remediation combined with washing solvents for the decontamination of zinc and lead from mine tailings. Samples were collected from various locations within the Angouran mine in Zanjan, Iran, and analyzed for total metal concentration using the standard ICP method. Electrokinetic tests were conducted using different washing solutions-hydrochloric acid, nitric acid, acetic acid, and sulfuric acid-each at a concentration of 0.1 M and mixed with soil in a 1:2 solution-to-solid ratio. A voltage of 1.5 V/cm was applied throughout the experiments. To mitigate heavy metal precipitation near the cathode, the same chemical solutions were used in the cathode chamber. The results demonstrated that distilled water resulted in the lowest removal efficiency for zinc (16%) and lead (11.5%), while hydrochloric acid showed the highest removal efficiencies of 64% for zinc and 45% for lead. These findings indicated that electrokinetic remediation, particularly when using hydrochloric acid as a complexing agent, was an effective method for removing significant quantities of zinc and lead from contaminated soil.