Removal of Arsenic and Sulfates from an Abandoned Mine Drainage by Electrocoagulation. Influence of Hydrodynamic and Current Density

Abstract

This paper presents a study of arsenic and sulfate removal from an abandoned mine drainage in Guanajuato Mexico (As 24 p.g L-1, SO42- 3567 mg L-1, pH 7 and conductivity 3.56 mS cm-1) by electrocoagulation (EC) using aluminum as the sacrificial anode in a continuous filter press reactor. The concentration of arsenic decreased from 24 p.g L-1 to 1.8 and 2 p.g L-1 at current density of 4 and 6 mA cm-2, respectively, at mean linear flow velocity of 1.82 cm s-1, enabling to reach the standard of the World Health Organization for arsenic in water (CAs < 10 p.g L-1). Sulfate was also partially removed during the EC from 3567 to 1686 mg L-1 at 4 mA cm-2 and 1.82 cm s-1.