Spontaneous arsenic (III) oxidation with bioelectricity generation in single-chamber microbial fuel cells

Arsenic is one of the most toxic elements commonly found in groundwater. With initial concentration of 200 μg L−1, spontaneous As(III) oxidation is realized completely during 7 days operation in single-chamber microbial fuel cells (MFCs) in the present study, with the maximum power density of 752.6 ± 17 mW m−2. The product is less toxic and mobile As(V), which can be removed from aqueous solution more easily. High-throughput 16S rRNA gene pyrosequencing analysis indicates the existence of arsenic-resistant bacteria as Actinobacteria, Comamonas, Pseudomonas and arsenic-oxidizing bacteria as Enterobacter, with electrochemically active bacteria as Lactococcus, Enterobacter. They interact together and are responsible for As(III) oxidation and bioelectricity generation in MFCs. This study offers a potential attractive method for remediation of arsenic-polluted groundwater.