矿浆中和酸性废水系统中硫酸盐还原功能菌群结构与环境响应特征

Community structure and environmental adaptation of sulfate-reducing bacteria in the acid mine drainage treatment system using alkaline slurry

摘要:

背景 碱性矿浆中和酸性矿山废水处理系统中，矿浆所含细菌参与SO₄^2-和金属的协同转化，并受到pH、有机物和悬浮固体浓度等环境因素的影响。目的 该过程中菌群对环境条件的响应特征仍需明晰。方法 本研究对酸性矿山废水、矿浆和废水中和处理系统内细菌菌群结构进行了解析，探讨了环境因素对优势硫酸盐还原菌(sulfate-reducing bacteria, SRB)菌属丰度的影响，阐释了处理系统中菌群间相互影响及代谢促进机制。结果 废水处理系统中微生物多样性较酸性废水和矿浆更为丰富，优势SRB属于脱硫弧菌属(Desulfovibrio)和脱硫杆菌属(Desulfitobacterium)，2种功能菌属总相对丰度达到3.3%-3.8%。混合菌群中包含多种具有利用难降解有机物功能的菌群，以及促进菌胶团形成的功能菌群，能够缓解外界有毒物质对SRB的抑制作用。代谢功能预测结果显示，混合菌群通过加强物质传输、群体感应等代谢功能，促进碳、氮、硫物质的转化活性，进而调控SO₄^2-和金属的转化能力。结论 在矿物颗粒和菌群间的物质交换作用影响下，废水处理系统中硫酸盐功能菌群生长和代谢的稳定性得到提升。本研究为扩展酸性废水生物处理工艺适用范围与保障矿山水环境安全提供了理论支持。

Abstract:

Background In the acid mine drainage (AMD) treatment system using alkaline slurry, sulfate reducing bacteria (SRB) contained in alkaline slurry could be introduced into the system and participate in the transformation of SO₄^2- and metallic substances. This process is susceptible to environmental conditions including pH value, organic substances, and suspended solid (SS) concentration.Objective The bacterial responses to environmental conditions during this process require further clarification.Methods In the current study, the characteristics of bacterial community structures in the wastewater treatment system, AMD, and slurry were analyzed. On the basis of microbial analysis, the influences of environmental factors and microbial interactions on the growth and metabolism of SRB in the AMD treatment system were elucidated.Results The results demonstrated that the microbial diversity in the treatment system was superior to that in AMD and alkaline slurry. The dominant SRB were affiliated to Desulfovibrio and Desulfitobacterium, the total relative abundance of which reached 3.3%-3.8%. The microorganisms with the functions of decomposing refractory organic matter and promoting Zoogloea formation mitigated the inhibitory effects of external toxic substances on SRB. Moreover, the mixed microbial flora promoted the microbial conversion activity of carbon, nitrogen, and sulfur substances by enhancing metabolic functions such as substance transport and quorum sensing, thereby elevating the transformation activity of SO₄^2- and metallic substances.Conclusion The microbial mass exchange and existing of SS enhanced the stable growth and metabolism of SRB. This study provides a theoretical basis for optimizing AMD treatment systems using biological approaches and supporting the protection of mining environments.