选取代表性土壤粘粒矿物、细菌和腐殖质，通过微宇宙模拟实验、未污染土壤输入重金属的长时间培养试验，以及重金属污染土壤添加有机物料和重组菌的田间小区试验，借助等温吸附、表面位点分析、红外光谱、等温微量热滴定、电镜-能谱及X-射线吸收光谱等现代分析技术，以Cu、Cd、Pb等重金属为对象，探讨土壤矿物-有机物－微生物互作界面重金属的宏观吸附量、亲和力、分布、化学形态、官能团、热力学特征及键长与配位数等。从分子水平揭示重金属在多组分界面的结合机制与影响因素，摸清土壤中重金属形态随时间、有机物含量和微生物数量转化的规律，明确不同土壤组分在重金属离子固定中的作用和贡献,构建土壤重金属固定与释放的数学模型，根据影响重金属表面行为和有效性的环境因素及土壤有机物和微生物数量等，提出调控土壤重金属转化的方法。推动土壤矿物-有机物-微生物相互作用及重金属环境化学研究的深入，为重金属污染土壤原位修复提供理论支撑。

The representative soil reactive components such as clay minerals, bacteria and humic substance are selected. Experiments of microcosm, long-term soil cultivation with input of heavy metals and field treatments of contaminated soils with organic materials and recombinant bacteria will be conducted. The isothermal adsorption, surface site analysis, attenuated total reflection Fourier transformation infrared spectroscopy (ATR-FTIR), isothermal titration calorimetry (ITC), scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and X-ray absorption fine structure (XAFS) studies will be employed to investigate the adsorption quantity, affinity, distribution, functional groups, thermal kinetics, atomic separation distances and coordination numbers of Cu, Cd and Pb at the interaction interface of soil mineral-organic matter-microorganims. The binding mechanisms of heavy metals on the interfacial surface of multi-components at the molecular level are elucidated. The transformation patterns of heavy metal species in soil with time, organic matter and microorganisms are characterized. The role and contribution of different soil components in the immobilization of heavy metals could be discriminated. The mathematic models for the immobilization and release of heavy metals in soil are established. Possible strategies for regulating the transformation of heavy metals in soils will be proposed based on both of the environmental factors and soil properties including the content of organic matter and microorganisms that influence the interfacial behavior of heavy metals. The study may facilitate the advances in the research field of soil mineral-organic matter-microorganism interactions and environmental chemistry of heavy metals. The results obtained will also provide scientific basis for the in-situ remediation of heavy metal-contaminated soils.