厌氧环境下As(III)在氧化铁和硅酸盐矿物界面作用影响或决定其在土壤中的迁移转化。Fe(II)是铁元素在厌氧环境中常见形态，它们通过一定反应可改变氧化铁和硅酸盐矿物结构及界面特性，影响As(III)在矿物表面的吸附、氧化还原等作用。土壤中两类矿物常以复合体形态存在，复合过程中矿物微结构和表面化学性质的变化会改变它们与Fe(II)和As(III)作用特性。然而有关Fe(II)存在条件下As(III)在氧化铁-硅酸盐矿物复合界面作用特性和机制还不明确。本项目拟通过应用分子环境土壤学技术和理论，结合表观热力学和动力学研究，探讨Fe(II)存在条件下As(III)在氧化铁-硅酸盐矿物复合界面作用的特性与微观机制，明确Fe(II)作用对As(III)形态和复合界面特性变化影响，揭示Fe(II)和As(III)在矿物复合界面共作用特性与机制，为深入阐明厌氧环境下铁和砷元素的地球化学过程提供理论依据。

The interactions between arsenite and iron oxides and phyllosilicate minerals have a significant influence on arsenite transfer and form changes in natural anoxic environments. Fe(II) ion is one of main species of iron in natural anoxic environments, and they could influence the adsorption and redox reactions of As(III) on the surfaces of iron oxides and phyllosilicate minerals by various.interactions to change the types and surface properties of the minerals. Iron oxides and phyllosilicate minerals are often simultaneously present and tend to form associations in soils, and the surface chemical characterizations of the associations are markedly different from the single minerals. However, the interactions between As(III) and iron oxides-phyllosilicate associations in the present of Fe(II) have not been established. The current proposal focuses on the reaction of As(III) with iron oxides-phyllosilicate associations in the present Fe(II). The dynamical properties of systems will be observed to reveal the reactions, and the interaction mechanisms will be proposed at molecular scale by using XRD, SEM/EDS, HRTEM/EDS, FT-IR, XPS, and XAFS. These results will be useful to understand Fe(II) roles in As(III) ions migration and forms change on the interface of the associations. It will also offer scientific evidences on environmental geochemistry of arsenic and iron cycle in natural environments.