Influence of PH and time in the removal of hexavalent chromium present in aqueous solutions using electrocoagulation

Abstract

The present investigation consisted in demonstrating the influence of pH and time in the removal of chromium (VI) from an aqueous solution using electrocoagulation. To this end, a reactor of 900 mL of effective capacity was designed, in which 8 aluminum plates were conditioned with 75.6 cm2 of contact surface each (4 anodes and 4 cathodes), fed by a continuous energy source of 4 amps and 5 volts, to which 900 mL of chromium (VI) solution was added at 20.5917 ppm; likewise this solution was also made up of 0.05 M of sodium chloride. On the other hand, the pH level of the solution was varied (3, 5.5 and 8), taking samples of 10 mL at times of 5, 10 and 15 minutes for analysis. The optimum result of the process was found at a pH of 3 and in a time of 15 minutes, with a removal of 20.0652 ppm or 97.44% removal of chromium (VI). Therefore, it was demonstrated that pH and time influence the removal of chromium (VI), in an electrocoagulation treatment with aluminum electrodes.