Chemical impact of catholytes on Bacillus subtilis-catalysed microbial fuel cell performance for degrading 2,4-dichlorophenol

This study was to explore a Bacillus subtilis-catalysed microbial fuel cell (MFC) system for electricity generation and dichlorophenol degradation. Our research focused on understanding the chemical interactions of various catholytes having distinctive properties (oxidizing, buffering, and salinity) and their impacts on the electrochemical activities, bacterial growth and phenolic degradation in the MFC system. Our experimental results revealed that B. subtilis is a potential exoelectrogenic bacterium for producing current density of 64.0 mA/m2 while degrading 2,4-dichlorophenol in the MFC. Chemical properties of the catholytes and the pH change profiles could have significant impact on the bio-electrochemical activities, therefore the performance of the MFC system. Potassium persulfate was found to be the most suitable catholyte for generating the maximal power density of 9.5 mW/m2 with a peak current of 1.11 mA over a potential of 0.45 V, while degrading over 60% 2,4-dichlorophenol. The B. subtilis-catalysed MFC could be a feasible technology for removal of hazardous phenol pollutants from industrial wastewater, while generating electricity.