Co-substrates' influence on bioelectricity production in an azo dye-based microbial fuel cell

Abstract

Co-substrates have been known to influence bioelectricity output during dye degradation. This preliminary research is focused on understanding the variations of bioelectricity output when co-substrates glucose and nitrogen sources were added along with Congo red azo dye in a double-chambered microbial fuel cell (MFC). A novel bacterial consortium capable of azo dye degradation was added as the inoculant to the double-chambered MFC. Differences in bioelectricity output were noted when glucose alone, ammonium nitrate and ammonium phosphate alone were added as co-substrates with Congo red dye. MFC with 25 mg L−1 ammonium nitrate peaked 0.032V and 0.003A open circuit (OC) output after 8 h hydraulic retention time (HRT). This was followed by observing effects of glucose alone and glucose combined with nitrogen sources over 8 h. Peak voltage and current of 0.11V and 0.012A, respectively were achieved at 3 h HRT by experimental model with glucose alone as co-substrate.