Laboratory-Scale Bio-Treatment of Real Arsenic-Rich Acid Mine Drainage

Acid mine drainage (AMD) still represents a huge environmental problem. Technical and scientific breakthroughs are needed to decrease damages, treatment cost, waste production associated with AMD. The feasibility of combining continuously fed anaerobic sulfate-reducing bioreactor downstream iron oxidation step was tested, at laboratory scale, two types real arsenic-rich AMD waters from the site Carnoulès (France), that differed in acidity (pH 3.3 4.0), arsenic (As, 18 174 mg.L−1), metal concentrations. Iron remained solution, while up 99% As precipitated as amorphous orpiment bioreactor. Zinc (Zn) precipitation also observed, 99%; however, efficiency Zn less stable than As. presented bacterial community including Desulfosporosinus-related sulfate reducer. When effluents process were treated aerobic bioreactor, oxidized efficiently. efficient bio-precipitation coupled shown, thus opening perspective low-cost combination steps for removal arsenic, zinc, As-rich AMDs.