Removal of chromium from aqueous solutions and plating bath rinse by an electrochemical method

Abstract

In this work, a bipolar packed bed electrolytic cell having steel Raschig rings behaving as electrodes has been used to remove chromium in the form of Cr(VI) from aqueous solutions and a sample of plating bath rinse. Fe2+ions generated at the anode side of the electrodes have reacted with OH-ions generated at the cathode side forming Fe(OH)2 in this electrolytic cell.Cr(VI) have coprecipitated as Cr(OH)3 with Fe(OH)3 forming after the redox reaction between Fe(OH)2 and Cr(VI). Meanwhile other impurities have also removed besides Cr(VI) using this process. Removal rate of 100% for Cr(VI) has been achieved in the experiments done with different initial Cr(VI) concentration, duration of electrolysis and applied potential. Fully removal of Cr(VI) has also been achieved from the sample of plating bath rinse