A microbial fuel cell integrated with an absorption column for the removal of hydrogen sulfide from anaerobic wastewater treatment

Abstract

The presence of hydrogen sulfide in biogas produced from the anaerobic treatment of organic wastewater containing high sulfate concentrations has been a key concern for this type of wastewater. This study investigates the performance of a two-compartment single-chamber microbial fuel cell (MFC) integrated with a packed absorption column in the removal of hydrogen sulfide produced from the anaerobic treatment of organic wastewater containing high sulfate concentrations (~3,000 mg/L chemical oxygen demand (COD) and ~300 mg/L sulfate). The first and the sec-ond compartments of the system functioned as an anaerobic bioreactor and an MFC, respectively. The anaerobic compartment removed COD and sulfate at removal efficiencies of 81.3% ± 4.5% and 100% ± 0.0%, respectively, whereas the MFC compartment removed hydrogen sulfide in the effluent and biogas. The hydrogen sulfide concentrations in the biogas decreased from 14,540 ± 620 to 153 ± 63 ppm after the installation of the MFC with a packed absorption column. A maximum power density of 8.0 mW/m2 was achieved. The results of 16S rRNA gene clone libraries revealed the presence of a fermentative bacterium (Streptococcus macedonicus), a sulfur-oxidizing bacterium (Halothiobacillus neapolitanus), and an exoelectrogenic microorganism (Klebsiella pneumoniae) in the biofilm on the anode electrode.