The riverbed sedimentation zone is an important zone of hydrochemistry, and the biogeochemical action in this zone has a significant impact on groundwater quality. As the main area where hydrochemistry occurs, studying the law of hydrochemical evolution within 1 m below the riverbed is of great significance for understanding the migration and removal of river pollutants. In this study, a combination of onsite monitoring and indoor experiments was used to analyze the variation characteristics of the hydrochemical composition of pore water during riverbank infiltration, as well as the main hydrochemical effects and influencing factors. The results show that in the process of river water infiltration, a series of redox reactions occur in the riverbed sedimentation zone, and there are differences in different infiltration depths. From 0 to 20 cm below the riverbed, strong respiration and denitrification mainly occurred. Reductive dissolution of manganese minerals mainly occurred from 20 to 60 cm, and reductive dissolution of iron minerals mainly occurred from 60 to 90 cm. River water level, dissolved organic carbon content and microbial activity had varying degrees of influence on these redox effects. The recharge of river water infiltration ensures the exploitation amount of the pumping wells, but it also leads to the increase of some components in groundwater, and the extracted water cannot be directly drunk.

河床沉积带是重要的水化学带，该带的生物地球化学作用对地下水水质有显着影响。作为水化学发生的主要区域，研究河床以下1m内的水化学演化规律，对于了解河流污染物的迁移和去除具有重要意义。本研究采用现场监测和室内实验相结合的方法，分析了河岸入渗过程中孔隙水水化学成分的变化特征，以及主要的水化学效应和影响因素。结果表明，在河水入渗过程中，河床沉积区发生了一系列氧化还原反应，不同入渗深度存在差异。河床以下0～20 cm，主要发生强呼吸作用和反硝化作用。锰矿物的还原溶解主要发生在20～60 cm，铁矿物的还原溶解主要发生在60～90 cm。河流水位、溶解有机碳含量和微生物活动对这些氧化还原效应有不同程度的影响。河水入渗补给保证了抽水井的开采量，但也导致地下水中某些成分增加，提取的水不能直接饮用。溶解有机碳含量和微生物活性对这些氧化还原效应有不同程度的影响。河水入渗补给保证了抽水井的开采量，但也导致地下水中某些成分增加，提取的水不能直接饮用。溶解有机碳含量和微生物活性对这些氧化还原效应有不同程度的影响。河水入渗补给保证了抽水井的开采量，但也导致地下水中某些成分增加，提取的水不能直接饮用。