Electrokinetic Remediation of Electrolytic Manganese Residue Using Solar-Cell and Leachate-Recirculation

Abstract

Electrolytic manganese residue is a kind of acidic waste containing manganese and ammonia nitrogen produced in the process of hydrometallurgical of manganese metal smelting with manganese ore. It is primarily land ll treatment, occupying land resources and threatening human health. Through research of the leaching toxicity changes of electrolytic manganese residue and the leachate added, the feasibility of leachate recirculation and electrokinetic remediation of electrolytic manganese residue powered by solar-cell has been proved by experiments. The reaction mechanism was presumed by studying the changes of leaching toxicity, crystal formation and morphology of manganese residue during electrokinetic remediation. The results revealed that the removal rates of manganese and ammonia nitrogen in manganese residue were 99.49% and 99.70%, respectively, and ammonia nitrogen can be reduced to 2.26 mg/L and manganese concentration to 6.15 mg/L, when leachate was recirculated as electrolyte and a solar-cell provided the electrical energy for the remediation after 72 h. The focal mechanism of manganese and ammonia nitrogen conversion was electromigration and electrochemical oxidation.