Use of citric acid industrial wastewater to enhance electrochemical remediation of cadmium-contaminated natural clay

Citric acid industrial wastewater (CAIW) is a waste by-product generated by the manufacturing process of citric acid. Effective and economical treatment and disposal of the wastewater is an environmental challenge. A research program was launched to investigate the feasibility of using CAIW as an enhancement agent for electrochemical remediation of Cd-contaminated clay of high acid/base buffer capacity, so as to lower the cost of electrochemical remediation and to put a waste byproduct into productive use. The research program included batch experiments to quantify various soil-Cd-CAIW interactions and laboratory bench-scale electrochemical remediation experiments. The results indicate CAIW is a promising replacement for other more expensive synthetic chelating agents in the enhancement of electrochemical remediation. Details of the study are presented in the paper.