重金属在固液界面吸附过程的数学模拟是研究重金属吸附机理和预测重金属吸附行为的重要工具。表面络合模型的出现为解释吸附行为与机制提供了重要的科学基础。与传统表面络合模型相比，基于型体匹配的多吸附点位Langmuir模型（SML模型）不含经验参数，可调参数更少，模拟和预测效果好，且可应用于重金属离子在复杂介质上的吸附行为模拟，但SML模型的假设缺少理论验证且应用有待拓展。本项目将选取针铁矿、水铝矿和红壤作为典型矿物，利用扩展X射线吸收精细结构谱解析重金属与典型矿物表面的界面反应模式，基于典型矿物吸附点位和重金属离子水解产物的型体分布及重金属吸附机制构建相应的SML模型，模拟重金属离子在典型矿物上的吸附及竞争吸附行为，明确不同型体重金属离子的吸附常数，并对重金属离子在典型矿物上的（竞争）吸附行为和吸附等温线进行预测。课题的开展对完善SML模型的理论基础、拓展其应用范围具有重要意义。

Modeling adsorption of heavy metals on solid-water interface is important for understanding adsorption mechanisms of heavy metals and predicting their adsorption behavior. The surface complexation model offers important scientific foundation for explaining adsorption behavior and mechanisms. Compared to traditional surface complexation models, the speciation-based multi-site Langmuir model (SML model) does not contain empirical parameters. Moreover, it can simulate and predict the adsorption data with much less adjustable parameters. However, the SML model has some limitations with regard to its assumption and theoretical foundation. This project will determine the adsorption mechanisms of Cu2+, Cr3+, Pb2+, Zn2+, Cd2+, Ni2+, Co2+ on typical minerals including goethite, gibbsite and red soil with EXAFS. The SML model will be set up based on the distribution of various surface site species and hydrolysis products of heavy metals as well as the complexation modes of heavy metal with the mineral. The adsorption and competitive adsorption behavior of heavy metals on typical minerals will be simulated with the SML model and the corresponding adsorption constants can be determined. Moreover, the adsorption constants will be employed to predict the adsorption isotherms and (competitive) adsorption edge of heavy metals on these typical minerals. This project is of great significance in improving the theoretical foundation of SML model and improve metal adsorption modeling under field conditions.