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 SO24 concentration of wastewater was 3,000 mg/L, the SO24 removal efficiency was 51.6% for the SRB system, 76.3% for the Fe þ SRB system, and 92.0% for the Fe/Cu þ SRB system. Moreover, Pb2þ,Cu2þ and Zn2þ ions were completely removed. The results demonstrate that the Fe/Cu þ SRB system had apparent advantages over the SRB system, especially at low pH. This study demonstrates that an Fe/Cu þ SRB system could be a promising technology for treating wastewater containing high concentrations of sulfate and heavy metals.