硫酸盐还原菌包覆矿石控制酸性废水排放及碳源的优选研究

本研究基于实验室筛选、培养的硫酸盐还原菌(Sulfate-reducing bacteria,简称SRB)菌群,分别考察以麦芽糊精、污泥、乙醇、乳酸钠等为碳源时SRB的生长状况,同时模拟野外环境进行柱淋滤实验,分析在不同碳源作用下原位控制酸性矿山废水的效果。结果表明,采用这4种碳源时,SRB还原硫酸盐能力的大小依次为:乙醇麦芽糊精乳酸钠污泥,对SO24-的去除率分别为91.9%、86.9%、83.4%和65.0%。模拟实验结果表明,接种SRB并在初期补充碳源,能有效控制含硫废石的SO24-释放和酸性矿山排水的产生,以乙醇、麦芽糊精、乳酸钠和污泥为碳源对雨水淋溶时SO24-的减排率分别为84.8%、76.2%、69.9%、54.0%。综合考虑经济性和污染控制能力,麦芽糊精是较理想的工程碳源,培养7天后能在矿石表面广泛覆膜,生物膜中优势菌群为Proteobacteria、Firmicutes和Bacteroidetes,能有效控制硫的氧化与酸性排水的产生。

Sulphate-reducing Bacteria Covered Mine Refuse to Control Acid Mine Drainage and the Optimization of Relevant Carbon Sources

The growth of sulfate reducing bacteria (SRB), that obtained by the laboratory screening and culturing, was investigated with maltodextrin, sludge, ethanol, or sodium lactate as carbon source, respectively. The effect of different carbon sources on the in-situ control of acid mine drainage was analyzed by column leaching experiment in simulated field environment. The results showed that the ability of SRB to reduce sulfate was reduced in the order of ethanol > maltodextrin > sodium lactate > sludge in terms of different carbon sources, with sulphate removals of 91.9%, 86.9%, 83.4%, and 65.0%, respectively. Simulation experiments showed that the immediate addition of carbon source after the inoculation of SRB can effectively control sulphate release from sulfur-containing ores and the production of acid mine drainage. When ethanol, maltodextrin, sodium lactate, or sludge was used as the carbon source, the amount of sulphate release by rainwater leaching was reduced by 84.8%, 76.2%, 69.9%, and 54.0%, respectively. Considering the cost and pollution control ability, maltodextrin is an ideal carbon source which forms biofilms on the surface of ores after seven days of culturing. The dominant bacteria in the biofilm, including Proteobacteria, Firmicutes, and Bacteroidetes, can effectively control the oxidation of sulfur and the generation of acid drainage.