Electrochemical Oxidation of Cyanide and Simultaneous Cathodic Removal of Cadmium Present in the Plating Rinse Water

Abstract

The electrochemical oxidation of cyanide, with the simultaneous recovery of cadmium present in a typical plating rinse wastewater, was conducted in a bipolar capillary gap disc stack electrochemical reactor under batch recirculation mode. The concentrations of cyanide and cadmium present in the reservoir of the batch recirculation system were measured as a function of electrolysis time at various flow rates, pH values, and applied cell potentials. The objective of this work was to explore the feasibility of using a bipolar disc electrochemical reactor that consisted of graphite as the electrodes to remove cyanide and Cd ions from the plating industry effluent using batch continuous recirculation modes. Experimental results showed that the reactor was able to reduce (from rinse water with a cyanide concentration of 240 mg/L and cadmium concentration of 50 mg/L) the content of toxic species by more than 99%, so that the treated water can be reused for further operations.