基于微生物诱导碳酸钙沉淀固化重金属污染土的微观机理与耐久性研究

Microbial induced calcite precipitation (MICP) is available for remediation of heavy metal contaminated soils because its highlighted advantages such as environmental friendly, quick and efficient, strong applicability and so on. The project aims at studying the mechanism and durability of the artificially prepared heavy metal contaminated silt treated by MICP. Firstly, researching the main factors affected MICP, revealing the interactions between heavy metal ions and MICP, as well as the mechanism. Secondly, investigating the engineering properties of MICP stabilized contaminated soils, and proposing the preliminary scheme of remediation. Thirdly, biochemistry mechanism of the MICP stabilized contaminated soils will be revealed based on the analysis of microstructure, mineral compositions and chemical components etc. Finally, researching the stability of MICP stabilized contaminated soils under different environmental conditions, such as cyclic wetting and drying, acid rain penetration, cyclic freezing and thawing. Revealing the mechanism of the variation of the engineering properties. Subsequently, coming up with the optimized designing scheme of MICP stabilized contaminated soils based on durability, which offers the theory and technique support to the practical engineering applications of MICP. This project will promote the development and improvement of the theory and technique of the MICP treated heavy metal contaminated soils. It has a broad application prospect, and can be applied to the other fields, such as saline soils and the environmental pollution in mines.

微生物诱导碳酸钙沉淀（MICP）具有绿色环保、快速高效、适用性强等突出优点，可用于重金属污染土修复。以人工制备的重金属污染粉土为研究对象，着重研究MICP修复重金属污染土机理与耐久性。首先，掌握影响MICP的主要因素，获取重金属离子与MICP的相互作用规律，揭示其作用机理；其次，研究MICP固化污染土的工程性质，提出优化设计初步方案；第三，进行MICP固化污染土的微观结构、矿物成分与化学成分分析，结合生化反应研究，揭示MICP修复重金属污染土生化作用机理；第四，研究MICP固化污染土分别在干湿循环、酸雨入渗、冻融循环作用下的稳定性，揭示其工程性质变化微观机理，进一步提出基于耐久性的MICP固化污染土优化设计方法，为MICP实际工程应用提供理论与技术支撑。本课题将推动MICP修复重金属污染土理论与技术的发展和完善，可拓展应用于盐渍土、矿山环境污染治理等领域，具有广阔的应用前景。

微生物诱导碳酸钙沉淀（MICP）是一种将化学固化与微生物修复结合的地基加固新技术，具有绿色环保、快速高效、适用性强等突出优点，可用于重金属污染土修复。本项目以人工制备的重金属污染粉土为研究对象，阐明了MICP修复重金属污染土机理与耐久性。. 首先，揭示了菌液浓度、钙离子浓度、尿素浓度、温度及初始Ph值等MICP的主要影响因素，阐明了重金属离子与MICP的相互作用规律和机理。. 其次，明晰了MICP固化污染土的强度、变形、渗透特性及环境效应，提出了MICP固化重金属污染土优化设计初步方案。. 第三，通过MICP固化污染土的微观结构、矿物成分与化学成分分析，结合生化反应研究，揭示了MICP修复重金属污染土生化反应过程和微观机理，建立了MICP固化重金属污染土生化作用模型。. 第四，开展了MICP固化污染土分别在干湿循环、酸雨入渗、冻融循环作用下的稳定性模拟，揭示了复杂环境下MICP固化污染土的工程性质演化规律，并进一步提出基于耐久性的MICP固化污染土优化设计方法，为MICP实际工程应用提供理论与技术支撑。. 项目成果已发表学术论文24篇，其中，SCI收录论文23篇；申请/授权发明专利13项（已授权4项 ）；培养青年教师1名，研究生7名（5名已毕业、2名在读）。. 本项目将推动MICP修复重金属污染土理论与技术的发展和完善，可拓展应用于盐渍土、矿山环境污染治理及土体加固等领域，具有广阔的应用前景。