Enhanced sulfolane-contaminated groundwater degradation and power generation by a mini tubular microbial fuel cell/electro-Fenton combined system

A tubular microbial fuel cell/electro-Fenton (MFC/EF) combined system was developed for field-scale applications. This tubular MFC/EF combined system treats groundwater containing sulfolane by driving the Fenton reaction at the cathode using bioelectricity that is generated at the anode. Proper aeration and an adequate supply of carbon were found to improve significantly the performance of a tubular MFC/EF combined system. The tubular MFC/EF combined system exhibited high voltage output (525 mV) and high power density (691 mW/m3). The generation of H2O2 from the cathode at 1 L/min aeration was 20 times that at 0.1 L/min, and achieved 100% removal efficiency of sulfolane (50 mg/L). The bicinchoninic acid assay detected an increase in the amount of bacteria by a factor of 2.2 as a result of electrical stimulation following tubular MFC/EF operation. The biotoxicity of sulfolane after tubular MFC/EF treatment revealed that the light inhibition of Vibrio fischeri was only 4% at 1 L/min aeration, owing to the by-product (SO42-). The results demonstrated that the tubular MFC/EF combined system was effective in removing sulfolane and reducing the toxicity of by-products in the purification of water.