Effect of anodic metabolic function on bioelectricity generation and substrate degradation in single chambered microbial fuel cell.

Influence of anodic metabolic function viz., aerobic, anoxic and anaerobic on bioelectricity generation was evaluated in single chamber mediatorless microbial fuel cells (non-catalyzed graphite electrodes; open-air cathode) during wastewater treatment under similar operating conditions (pH 7; ambient temperature/pressure). Despite the fluctuations observed, aerobic metabolic function (379 mV; 538 mA/m2) documented higher power generation compared to anoxic (251 mV; 348 mA/m2) and anaerobic (265 mV; 211 mA/m2) operations. Relatively higher treatment efficiency was also evidenced in aerobic operation (COD removal efficiency; 77.68% (aerobic), 56.84% (anoxic), 48.68% (anaerobic)). Polarization behavior, bioelectrochemical analysis, sustainable resistance and cell potentials also supported the aerobic operation. Aerobic metabolic function showed potential to generate higher power and substrate degradation over the corresponding anoxic and anaerobic metabolic functions. The relative efficiency of power generation observed in aerobic microenvironment might be attributed to effective substrate oxidation and good biofilm growth observed on the anodic surface. Presence of lower dissolved oxygen concentration in anodic chamber due to the establishment of equilibrium between substrate oxidation and oxygen scavenging might also contributes positively to power generation in aerobic operation.