基于硫酸盐还原菌的含镉酸性矿山废水的治理及微生物群落特征

Treatment and Microbial Community Characteristics of Cadmium-Containing Acid Mine Wastewater Based on Sulfate-Reducing Bacteria

摘要: 酸性矿山废水(AMD)危害是采矿业面临的最严重的环境问题之一。利用硫酸盐还原菌(SRB)处理AMD是一种低碳、绿色、经济，具有广阔应用前景的技术。本文从煤矿煤层水中富集到一组硫酸盐还原菌群(SRBs)，进行高通量测序后发现具有硫酸盐还原能力的是脱硫弧菌属(Desulfovibrio)、脱硫弯曲孢菌属(Desulfosporosinus)、脱硫生孢菌属(Desulfurispora)。探究了SRBs在不同初始Cd²⁺浓度下的生长、硫酸盐还原和Cd²⁺的去除情况，及在不同重金属浓度的模拟AMD中微生物群落的特征。结果表明，随着Cd²⁺浓度的增加，OD₆₀₀逐渐降低，SO₄^2-和Cd2+的去除率也逐渐降低。当Cd²⁺浓度为5 mg/L时，OD₆₀₀、SO₄^2-和Cd²⁺的去除率均达到最大，分别为0.706、100%和100%。利用高通量测序研究SRBs处理不同重金属浓度的矿山酸性废水中微生物群落特征表明，一定范围内，重金属离子浓度的增加并不会显著改变该SRBs的群落结构，该SRBs具有较好的重金属耐受性。此外，微生物相关性网络分析表明，具有硫酸盐还原能力的菌属脱硫弯曲孢菌属(Desulfosporosinus)、脱硫弧菌属(Desulfovibrio)、脱硫生孢菌属(Desulfurispora)与其他菌属共同促进硫酸盐还原过程的发生。因此，该SRBs具有良好的硫酸盐还原能力和重金属耐受性，可用于含重金属酸性矿山废水的治理。

Abstract: Acid mine drainage (AMD) pollution is one of the most serious environmental problems restricting the development of mining industry. Sulfate-reducing bacteria (SRB) treatment of AMD is a low-carbon, environmentally friendly and economical technology with broad application prospects. In this study, a group of sulfate-reducing bacteria (SRBs) were enriched from coal seam water in coal mines. Desulfovibrio, Desulfosporosinus and Desulfurispora were identified by high-throughput sequencing. The growth, sulfate reduction and Cd²⁺ removal of SRBs at different initial Cd²⁺ concen-trations, and the changes of microbial communities in simulated AMD at different heavy metal concentrations were explored. The results showed that the OD600 gradually decreased with in-creasing Cd²⁺ concentration and the removal rate of and Cd²⁺ also gradually decreased. The reduction rate of SO₄^2- and Cd²⁺ also decreased gradually, and the removal rate of SO₄^2- and Cd could reach 100% when the concentration of Cd²⁺ was 5 mg/L. Using high-throughput sequencing to study the characteristics of microbial communities in SRBs treating mine acid wastewater with different concentrations of heavy metals showed that the increase in the concentration of heavy metal ions within a certain range did not significantly change the community structure of the SRBs. The SRBs have good tolerance to heavy metals. In addition, microbial correlation network analysis showed that the bacterial genera Desulfosporosinus, Desulfovibrio, and Desulfurispora with sul-fate-reducing ability jointly promoted sulfate recovery. Therefore, it has good sulfate reduction ability and heavy metal tolerance, and can be used for the treatment of acid mine wastewater containing heavy metals.