Electrochemical remediation of metal-bearing wastewaters Part I: Copper removal from simulated mine drainage waters

Abstract

A bench-scale electrochemical cell for plating heavy metals, such as copper from dilute wastewaters, was designed and tested. Optimization tests were performed on simulated mine-drainage water (pH 2.6, 0.1 M Na₂SO₄, 0.02 Ω⁻¹ cm⁻¹, 150 mg L⁻¹ Cu²⁺) using a vertically oriented, flow-through cell containing a carbon felt cathode. Results obtained for optimized conditions of applied potential and volume flow rate demonstrated greater than 99.9% recovery of copper metal from feed solutions at an ohmic corrected potential of −0.70 V vs Ag/AgCl and flow rates approaching the design maximum of about 0.30 mL s⁻¹. The effluent concentration of copper under conditions of optimum potential and flow rate could be routinely reduced to a target level of 50 μg L⁻¹.