Electrolytic Toxic Metal Removal from Effluents using Reticulated Vitreous Carbon

Abstract

SUMMARYWith the discharge of toxic metal laden effluent being a major environmental and economic concern to many metal finishing industries, the process of electrodeposition offers a clean and efficient method of removing and recovering such pollutants. A technique for the electrolytic removal of metal ions from acidified copper sulphate streams using reticulated vitreous carbon (RVC) electrodes is described. The very high specific surface area values (up to 6600 m2/m3) and high porosity (approximately 97%) of this form of carbon coupled with its availability in several grades (related to the foam pore size) made it a potentially attractive electrode material. A laboratory scale rig employing a flow-by electrode cell with an RVC cathode was constructed to allow performance evaluation of batch recycle or continuous modes of operation. Extraction efficiencies of over 80% for continuous operation and 99% for batch recycle operations were achieved using solutions containing 300 ppm copper. Process details and economic estimates for a typical system able to meet current regulatory standards are also discussed.