The effect of microbially mediated sulfate reduction on arsenic mobilization in the shallow aquifer from Jianghan Plain, central Yangtze River Basin

To understand the coupled Fe-S biogeochemical processes controlling the fate and transport of As in alluvial aquifers systems, microcosm incubation experiments were implemented with sediments collected from the shallow aquifer systems in the Jianghan Plain, central Yangtze River Basin. The microcosms were conducted by mixing 5 g sediments with 50 mL artificial groundwater and incubated under anaerobic condition for 75 days, a control group with amendment of acetate were also set up for comparing the influence of exogenous input of organic carbon. Dissolved As species (including thio-As), Fe(II), dsrB/arrA functional gene abundance, 16S rRNA gene sequences and iron mineral phase transformation (by sequential extraction) were monitored during the incubation.