Electrochemical chromic acid regeneration process with fuel-cell electrode assistance. Part I: Removal of contaminants

This paper presents the results of work carried out on a laboratory cell for regeneration of spent hard chrome plating solution. The electrolysis cell consists of a rectangular tank divided into two compartments with an ion exchange membrane (Nafion-117), and uses a lead anode and a gas diffusion electrode as the cathode. The laboratory scale cell was used as a simulated plating bath containing Cu2+, Fe2+, Ni2+, and Cr3+ as contaminants, for different experimental conditions at room temperature. The separation performance of the process was assessed by operating the cell under three constant current conditions. The cell was also tested under different initial concentrations and catholyte-to-anolyte volume ratios. The results indicate the possibility of decreased energy consumption and better removal rates over traditional methods.