Advection of surface-derived organic carbon fuels microbial reduction in Bangladesh groundwater.

ABSTRACT: Chronic exposure to arsenic (As) by drinking shallow groundwater causes widespread disease in Bangladesh and neighboring countries. The release of As naturally present in sediment to groundwater has been linked to the reductive dissolution of iron oxides coupled to the microbial respiration of organic carbon (OC). The source of OC driving this microbial reduction--carbon deposited with the sediments or exogenous carbon transported by groundwater--is still debated despite its importance in regulating aquifer redox status and groundwater As levels. Here, we used the radiocarbon ((14)C) signature of microbial DNA isolated from groundwater samples to determine the relative importance of surface and sediment-derived OC. Three DNA samples collected from the shallow, high-As aquifer and one sampl

SUBMITTER: Mailloux BJ 

PROVIDER: S-EPMC3619377 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature