Isolation And Identification Of A Sulfate Reducing Bacteria And The Application In Uranium-Bearing Mine Wastewater Treatment

After decommissioning of acid in-situ leaching uranium mines,groundwater will cause potential hazards to groundwater due to its low p H and high content of sulfate and U6+.Therefore,the treatment of such wastewater and the restoration of groundwater are extremely important.In this paper,taking the groundwater after the acid leaching of Xinjiang uranium mine was stopped as the research object,a common desulfurizing Vibrio strain（Gn LF21）with uranium removal and desulfurization ability was enriched,separated,purified and identified from a garbage leachate,and used this strain to carry out experimental research on the removal of U（Ⅵ）and sulfate radicals in raw water and diluted raw water,and achieved good results.Mainly the following results were obtained:（1）The Gn LF21 was obtained from the leachate of a landfill in Nanchang,enriched,purified and identified.The purified strain Gn LF21 has a homology of 97.37%with Desulfovibrio vulgaris strain DSM 644,so the strain was tentatively named Desulfovibrio vulgaris strain Gn LF21.Gram identification showed that the strain was a Gram-negative bacteria,and scanning electron microscope identification showed that the bacteria were arc-shaped.（2）The results of the single-factor experimental study on the factors affecting the desulfurization of the Gn LF21 showed that it had a higher desulfurization rate when the temperature was 35°C,the carbon source was sodium lactate,and the p H is 7.0,the desulfurization rate is high,and the desulfurization ability is still in the lower temperature range of 17°C～20°C.（3）The Gn LF21 has a high removal rate of 97.9%when the uranium concentration is≤5 mg/L,while the removal rate is only about 14.0%for the uranium concentration of8～10 mg/L U（Ⅵ）.（4）The Gn LF21 can remove simulated uranium-containing wastewater,the higher the bacterial solution inoculum,the higher the removal rate of U（VI）and SO₄^2-.The initial concentration of U（VI）was 1.8 mg/L,the concentration of SO₄^2-.was 1.2 g/L,the removal rate of U（VI）and SO₄^2-.can reach 80.7%and 92.9%with 20%inoculum in 120h.（5）The uranium removal mechanism of the Gn LF21 was preliminarily explained by SEM-EDS method and analysis of U,Fe,S,P and other elements in the sediment.