Contrasting kinetics of arsenic release from As-bearing ferrihydrite coprecipitates by distinct sulfate-reducing bacteria.

Microbial sulfate reduction plays key roles in arsenic (As) biotransformation and release in groundwater aquifers; however, influences by distinct sulfate-reducing strains on the transformation of As-bearing iron (oxyhydr)oxide under different sulfate availability and associated As mobilization are not clear. In this study, anaerobic batch experiments were conducted to clarify the transformation processes of As-bearing ferrihydrite mediated by two distinct sulfate-reducing strains. Results showed that both the purchased model strain Desulfovibrio vulgaris (D-1) and the Citrobacter sp.

Linking DOM characteristics to microbial community: The potential role of DOM mineralization for arsenic release in shallow groundwater.

Dissolved organic matter (DOM) play critical roles in arsenic (As) biotransformation in groundwater, but its compositional characteristics and interactions with indigenous microbial communities remain unclear. In this study, DOM signatures coupled with taxonomy and functions of microbial community were characterized in As-enriched groundwater by excitation-emission matrix, Fourier transform ion cyclotron resonance mass spectrometry and metagenomic sequencing. Results showed that As concentrations were significantly positively correlated with DOM humification (r = 0.