Removal of Chromium and Arsenic by Electrocoagulation in Waters at Neutral pH

Abstract

The objective of the research is to determine the effect of electric current and contact time on the decrease in the concentration of chromium and arsenic in water, for this purpose water sampling was carried out from a stream with concentrations of 11,099 mg/l of Cr and 2.53 mg/L of As, which were subjected to treatment in a reactor with a volume of 1L with stirring using iron electrodes as anode and this was the sacrificial one because it generated the same Fe2+ ions as then changed to Fe+3 which caused the reduction of chromium (VI) to chromium(III) on a graphite cathode. The results for both runs at both 2 and 3A demonstrated the influence of reaction time, electric current and electrodes are decisive in obtaining a removal of 99.99% of hexavalent chromium and 99.47% of As in the water, which is why which we conclude that the application of electric current in the treatment of water contaminated with hexavalent chromium and arsenic is efficient and it is possible to achieve concentrations of 0.016mg/L of Cr and 0.013mg/L of As for a current intensity of 3rd and 15 minutes of contact time which are below the Peruvian laws of both the mining and metallurgical sector regulated by supreme decree No. 010-2010-MINAM that establishes a maximum value of 0.1 mg/L and the supreme decree for discharges to the sewage system No. 010-2019-housing that establishes a value of 0.5 mg/L.