我国存在大面积受重金属离子污染的农田，已经严重威胁到当地生态环境的安全。本申请拟针对我国砖红壤、红壤、黄壤和暗棕壤等几种典型的土壤，利用X射线衍射、可见光漫反射光谱术等进行详细的矿物学工作，并在基于Rietveld技术的全谱拟合技术和漫反射光谱定量技术进行矿物的定量计算；在此基础上配制模拟土壤---“粘土-铁（铝）（氢）氧化物复合体”，然后在针对As、Cd、Cu、Pb、Zn等不同离子进行不同条件下（包括浓度、pH、Eh、温度等）的重金属离子的吸附和解吸附研究。利用包括XPS和ESR等技术探索重金属离子在复合体中的矿物吸附专属性差异、吸附位置和吸附机制等，并探索易于被解吸附的重金属离子的在矿物晶格中的位置进行研究，从而进一步探索延缓重金属离子解吸附的措施。该研究针对模拟土壤进行研究，研究的可操作性和可控性强，对于深刻理解土壤重金属离子的吸附和解吸附机制具有重要理论意义，同时也有一定的经济意义

A large percent of farmland was contaminated by heavy metals in China, and the contamination has threatened the local ecological environment. The application aims to study mineralogical components of the laterite, krasnozem, yellow soil and dark brown soils etc. by X-Ray diffractometry, Visible-light diffused reflection spectroscopy etc. Based on the careful mineralogical work, we prepare different "Clay mineral-Iron (Aluminum) (Hydrogen) oxide composites" according to the quantitative calculation of mineral phases using the combination of Vis-DRS and XRD techniques. Then the prepared composites are used to adsorb heavy metals, such as As, Cd, Cu, Pb, Zn etc. in different concentration, different pH and different Eh solutions. The mechanism and kinetics are studied by means the change of the concentration in the relict solution. The adsorption site on the mineral is studied by means ESR and XPS etc. Then, the heavy metal contained composited was leached by different solution with different pH, Eh etc. to explore the easy accessible site relate to which mineral. Finally, the solution of how to delay the release of heavy metals is reached. The study starts from the synthetic "soil", and it is easy controlled and carried out. It is of vitally importance to understand the mechanism of adsorption and desorption of heavy metals from contaminated soils, thus the study has both theoretical and economical significance.