Simultaneous arsenic(III) anaerobic oxidation with bioelectricity generation in microbial fuel cells

Abstract

Arsenic(As) is one of the most toxic elements commonly found in water and groundwater. Due to the limitation of anaerobic oxidation As(III) by traditional anaerobic treatment method, microbial fuel cells (MFCs) were applied to As(III) oxidation. A double chamber MFC with As(III) and sodium acetate(CH3 COONa) as electron donors was constructed, the transformation and migration of As(III) in the anode chamber under the stimulation of micro-voltage and the evolution of microorganisms were monitored. The results indicated that simultaneous As(III) anaerobic oxidation with bioelectricity generation were achieved only when CH3 COONa were required. The As(III) removal efficiency was 80% while the removal efficiency of traditional anaerobic treatment method was only 51% after a cycle of bioelectricity generation. The addition of As(III) with certain concentration could promote the power outputs of MFCs with itself being oxidized to less toxic As(V). Moreover, it was found that the migration of total As (including As(III) and As(V)) was from liquid phase to solid phase, and were enriched in sludge. It was also come to a conclusion that the activity of Acinetobacter and Pseudomonas with arsenic resistance was enhanced in the environment of longterm arsenic pollution by high throughput sequencing technology. This study offered a potential attractive method for remediation of arsenic-polluted groundwater.