The effects of operational parameters on the electrochemical removal of cadmium ion from dilute aqueous solutions

The electrochemical removal of cadmium ion from dilute aqueous solutions was studied in a rectangular spouted bed reactor by monitoring of cadmium ion concentration, instantaneous current efficiency and pH of catholyte and anolyte. A theoretical model was then developed for the electrochemical removal of metal ions on three-dimensional electrodes which was validated by gained experimental data. The effects of variation of operational parameters including initial concentration of cadmium ion, concentration of sodium sulfate electrolyte, applied electrical current density and catholyte initial pH were also investigated. It was observed that the initial concentration of cadmium ion had negligible effect on the removal efficiency of cadmium ion especially for the lower concentrations of cadmium ion, but affected the specific energy consumption significantly. A rise in the applied electrical current density increased the removal efficiency of cadmium ion and the specific energy consumption. The effect of electrolyte concentration on the electrochemical removal of cadmium ion was insignificant. The initial pH of the catholyte also did not affect the overall electrochemical process.