Abstract:Potential contamination of low pH，high SO42- and uranium concentration exists in groundwater after acid in-situ uranium leaching mines decommissioned. For this type of contaminated groundwater, a mixture enrichment, A3m-21ZLL, with dominant of Sulfate-Reducing Bacteria (SRB) which enriched from tailing heap of a uranium mine in southern China, was used to investigate the sulfate reducing capability, main influenced factors and effect of desulfidation to a acidic uranium-laden sulphate groundwater with apple peel fermented products as carbon source. The results show that the mix enrichment A3m-21ZLL is of better utilization for the apple peel fermentation products, the best m(COD)/m(SO42-) value is 7, and the best inoculum amount is 10%. The original concentration of SO42-, Fe2+ and U6+ in decommissioned uranium groundwater is 960.737, 47.6, 1.095 mg/L respectively, and the removal rate reaches 91.8%, 97.2% and 88.6%, respectively, and pH value rises from 3.98 to 5.78 after desulfidation. Among them, concentration of SO42- and Fe2+, and pH value meet the Chinese Groundwater Quality Criteria GB/T 14848—2017, Grade Ⅳ. It is feasible to treat uranium-laden sulfate groundwater by sulfate reducing bacteria with peel fermented solution as carbon source, the treatment effect is good, and the application prospect is very promising.