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。