Evaluation of Enhanced Electrokinetic Remediation of Arsenic from Cold Filter Cake: Zinc-Leaching Sediment

Abstract

In recent years, mining pollution has become a serious worldwide public health concern. One major issue in this field is concerned with arsenic-contaminated sediment. This paper, therefore, intends to determine the extent to which enhanced electrokinetic (EK) remediation is effective for remedying a case study of arsenic-contaminated sediment. The first section of this paper is devoted to determining the best enhancement agent at various solution concentrations and better discovering soil–metal action and reaction by leaching experiments. The sediment was collected from the zinc processing plant cold filter cake (CFC) in Shams Abad Industrial City, Iran, with a 5,700 mg/kg concentration of arsenic. In the second section of the study, ethylenediaminetetraacetic acid, citric acid, and sodium hydroxide as electrolyte conditioning solutions and sodium hydroxide for pretreatment have been evaluated as enhancement techniques for the remediation of arsenic-contaminated sediment during the electrokinetic method in tests with a duration of 8 days. Also, increasing the voltage gradient from 1 to 1.5 V/cm was assessed as another enhancement technique for improving the electrokinetic removal efficiency of arsenic. Finally, the result of experiments showed no significant increase in arsenic removal efficiency in using pretreatment and increasing the applied voltage; however, interestingly, using citric acid 0.5 M as the catholyte solution enhanced the removal efficiency up to 33.51%.