Effect of Nitrogen Cycling on Arsenic Release in Groundwater with High Arsenic Content
Groundwater with high As concentration often contains high NH4+components,but few studies have been conducted to investigate the effect of nitrogen cycling on the migration and release of As. The aquifer system in Jianghan Plain contains high arsenic as well as high content of ammonium in groundwater. The purpose of this study is to explore the effect of nitrogen reactive transport on the As release. In this study,the different water bodies in Jianghan Plain were sampled and their hydrochemical and isotopic indexes were tested,and hierarchical cluster analysis was performed on the sampling sites using the physicochemical indexes related to nitrogen and arsenic. The results show that along the direction of groundwater flow,due to the changes of groundwater redox conditions,the effect of nitrogen redox process on arsenic release process is different. Near the groundwater recharge area,the enrichment of NO3-in the relatively oxidized zone inhibits the dissolution of iron oxide. Along the groundwater flow path,the redox environment of aquifer system changes from oxidized to reduced condition. The enhanced denitrification occurring in the reduced environment could promote the dissolution of iron oxide,resulting in the release of As into groundwater. The denitrification is further enhanced in the groundwater discharge zone,and denitrification and DNRA using Fe2+as electron donor may influence arsenic release.
high arsenic groundwaternitrogencluster analysisJianghan Plainenvironmental geologyhydrogeology
NETL
NSTL
万方数据
