地下水排泄河水过程中会将缺氧地下水中的Fe²⁺与As³⁺带入含氧的交互带中，本研究旨在探明该过程中Fe²⁺与As³⁺随地下水在实际沉积物介质中的协同迁移转化机制.通过室内柱实验和批实验研究地下水排泄河水时Fe²⁺、As³⁺的迁移转化规律并获取其在交互带不同部位向固相转化（固化）的速率.结果表明：沉积物对Fe²⁺、As³⁺具有较强的吸附作用，As³⁺加快了Fe²⁺的迁移；Fe²⁺在流经交互带时发生化学氧化沉淀，形成了Fe-As结合态矿物.从远河处至近河处河处，Fe²⁺、As³⁺的固化速率加快.在整个交互带区域Fe²⁺明显促进了As³⁺的固化，在离河较近的区域As³⁺略微抑制了Fe²⁺的固化.地下水排泄河水过程中，Fe²⁺、As³⁺在交互不同部位以不同的速率发生协同化学氧化和吸附固定，从而严重阻碍其向河水方向迁移.

During groundwater discharge into the river, Fe²⁺ and As³⁺ in anoxic groundwater are brought into the oxygen-containing interaction zone. This study explores the co-migration and transformation mechanism of Fe²⁺ and As³⁺with groundwater in the natural sediment medium.The migration and transformation rules of Fe²⁺ and As³⁺during groundwater discharge into river water and the transformation rate of Fe²⁺ and As³⁺ to solid phase (solidification) in different regions of the interaction zone are studied by laboratory column experiment and batch experiment.The results show that the sediment strongly adsorbs Fe²⁺ and As³⁺, and As³⁺ accelerates the migration of Fe²⁺. The chemical oxidation and precipitation of Fe²⁺ occur, and Fe-As bounding minerals are formed when it flows through the interaction zone.The solidification rate of Fe²⁺ and As³⁺ is accelerated from the area far from the river to that near the river. In the whole interaction zone, Fe²⁺ significantly promotes the solidification of As³⁺, while As³⁺ slightly inhibits the solidification of Fe²⁺ near the river bank.In short, during groundwater discharge into river water, the synergistic chemical oxidation and adsorption fixation of Fe²⁺ and As³⁺in groundwater occur at different rates in different regions of the interaction zone, which seriously hinders their migration to river water.