Abstract:Sulfate pollution to the mining area and its surrounding groundwater was caused by perennial injection of sulfuric acid during acid in-situ leaching. To solve the problem, sulfate-reducing bacteria culture solution was used to simulate mine wastewater, and bioreactor was used to conduct cyclic batch tests and continuous operation tests. Effects of different fillers, circulating upward flow rate, hydraulic retention time (HRT), influent SO42- concentration, and COD/SO42- value on sulfate reduction were discussed. The test results show that the optimum operating conditions include sponge+K3 mixed filler, HRT=12 h, influent SO42- concentration of about 0.8 g/L, and COD/SO42-=2. The long-term operation results show that at 30 ℃, the effluent SO42- concentration can reach 0.10 g/L, and removal rate of SO42- is 87.9%, which meet the standard of groundwater class Ⅳ and above.