微生物胶结砂岩型地浸铀矿山隔水层的抗渗性能试验及机理研究

地浸采铀技术引起溶浸液、U（VI）和重金属离子等污染物通过渗透迁移作用威胁地下水资源，对人类的饮水安全造成巨大的影响，已成为制约地浸采铀技术发展的瓶颈。而微生物胶结技术是一种将化学固定与微生物原位胶结固定相结合的新技术，能有效的控制污染物向采区周围和地下水环境扩散。本项目拟以新疆某砂岩型地浸铀矿山为研究背景，采用现场测试、室内试验、理论分析相结合的研究方法，筛选出具有高效脲酶活性的优势菌株和具有强化微生物诱导碳酸钙沉淀作用的水溶性有机基质蛋白，在地浸采铀环境下，分析微生物胶结地浸铀矿山隔水层的晶体类型、矿化结构、抗渗性能和胶结效果，揭示微生物诱导碳酸钙沉淀胶结隔水层引起的物理性质、化学性质和生物性质等方面的变化规律，建立生物-化学耦合作用力学模型，分析其耦合作用机理，得到最优的工艺参数和技术条件。为控制和减少地下水环境污染，解决地浸采铀技术发展的关键问题，提供重要的理论指导和技术支撑。

The pollutants such as leaching solution, U(VI) and heavy metal produced in the process of in-situ uranium leaching (ISL) can seep through mine-containing aquifers and contaminate the underground water, which causes a great hazardous to the quality of drinking water and restrict the development of ISL. Biocement, a combination of chemical fixation and microbial in-situ cementation, is an emerging technology and can effectively prevent the diffusion of pollutants around the mining area to the groundwater environment. In the research proposal, field measurement, laboratory test, similarity simulation and theoretical analysis are to be used for the research. The dominant strains with high urease activity and water soluble organic matrix proteins which can enhance microbial induced calcium carbonate precipitation are to be selected, and the crystal types, mineralization structure, impermeability and cementation effect of aquifuge in in-situ leaching uranium mine induced by microbial cementation are to be analyzed, and the changes in physical, chemical and biological properties of calcium carbonate precipitate cemented aquifuge induced by microbial are to be investigated, and a bio-chemical coupling mechanical model is to be established, and the coupling mechanism is to be analyzed, and the optimal process parameters and technical conditions is to be obtained. The research results of the project can effectively reduce the groundwater pollution, and provide important theoretical guidance and technical support for solving the key problem of the development of ISL.