Enhanced biotreatment of acid mine drainage in the presence of zero-valent iron and zero-valent copper

Abstract

Batch laboratorial experiments were conducted to evaluate the potential of Fe0, Cu0 and sulfate-reducing bacteria (SRB) for reduction and removal of sulfate and heavy metals from synthetic acid mine drainage. The variation in solution pH indicates that the Fe0/Cu0 bimetallic system provided favorable conditions for SRB growth and sulfate reduction. When the SO42− concentration of wastewater was 3,000 mg/L, the SO42− removal efficiency was 51.6% for the SRB system, 76.3% for the Fe + SRB system, and 92.0% for the Fe/Cu + SRB system. Moreover, Pb2+, Cu2+ and Zn2+ ions were completely removed. The results demonstrate that the Fe/Cu + SRB system had apparent advantages over the SRB system, especially at low pH. This study demonstrates that an Fe/Cu + SRB system could be a promising technology for treating wastewater containing high concentrations of sulfate and heavy metals.

Keywords

• reduction
• sulfate-reducing bacteria
• sulfide
• zero-valent copper
• zero-valent iron