Recovery of copper from acid mine drainage by an integrated sulphate reducing process

An integrated sulfate reducing process was used to treat Acid Mine Drainage with high concentrations of Cu2+, Fe and SO42-. The water treatment system integrated a sulfidogenic UASB bioreactor with a precipitation reactor which was used to recover copper. Sodium lactate was used as energy source. The effective volume of the UASB reactor was 2 L and the hydraulic retention time was 12.57h. In the sulphate removal reactor, sulphate was removed from 21160 to 195 mg/L with a rate of 4427.8 mg/L/d. Cu2+ and Fe was removed by biologically generated S2- and OH- from 360 and 6520 to 0.049 mg/L and less than 10 mg/L respectively. The average COD, copper and iron removal rate was 2523.2, 15.21 and 274.98 mg/L/d separately. The effluent pH reached 6.0-7.0. The results showed potential usage of this bioreactor in treating Acid Mine Drainage.