Dissolved Lead Removal from Soil-washing Process Using Electrocoagulation

Abstract

Soil-washing using ethylenediamine-tetraacetate (EDTA) is an effective method for the remediation of lead (Pb) contaminated land. In practice, it is necessary to manage wastewater from this remediation process. The Electrocoagulation technique is an alternative method to remove Pb from soil-washing wastewater. The primary purpose of this study is to determine optimum conditions for the electrocoagulation process of Pb removal from soil-washing wastewater. This study used an electrochemical batch reactor with a monopolar parallel circuit. Based on the initial research, the Pb concentration in soil-washing wastewater was 3600 mg/L. Several parameters were used to obtain the optimal condition for Pb removal: operational voltage, type of electrode used, and time. The result showed that the optimum condition for Pb removal is on the operational voltage of 7 volt (V), using aluminium electrode pair, at an operating time of 80 min within the Pb removal efficiency of 96%. Furthermore, the kinetics study showed the highest Pb precipitation was 0.041/min following the first-order model. Using these optimal parameters, the Pb precipitation and removal efficiencies for real soil-washing wastewater were 0.0416/min and 96.7%, respectively. The electrocoagulation method is efficient for simultaneously removing lead from polluted effluents.