Treatment of simulation of copper-containing pit wastewater with sulfate-reducing bacteria (SRB) in biofilm reactors

A low-cost, long-term and maintenance-free method was put forward to treat simulation of copper-containing pit wastewater which has caused a widespread environmental problem in Yunnan Province, China. The objective of this work was to investigate the treatment of low concentrations of Cu2+ in the mine pit water with sulfate-reducing bacteria (SRB) using bagasse as both the slow-release carbon source and the carrier in biofilm reactors. Following the long-term trail experiment for 200 days, the Cu2+ concentration decreased from 10 to 0.2 mg/L in the SRB biofilm system. The result showed utilizing the bagasse as both the slow-release carbon source and the carrier in biofilm reactors showed good and stable performance for Cu2+ removal with long-term maintenance-free. Through the analysis of sediment samples indicated that the sediment was basically copper sulfide precipitate, which proved the feasibility of copper recovery in our bioreactors. It revealed the feasibility of bagasse for SRB to remove Cu2+ and provided a potential method to treat mine pit water.