Pre-fermentation of waste as a strategy to enhance the performance of single chambered microbial fuel cell (MFC)

Functional role of pre-fermentation of food waste (PFW) was studied to enhance the performance of single chambered microbial fuel cell (MFC) (mediatorless; non-catalyzed graphite electrodes; open-air cathode). Significant improvement in power output was noticed after pre-treatment (391 mV; 530 mA/m2) compared to unfermented waste (275 mV; 361 mA/m2). MFC performance was found to depend on applied organic load and nature of substrate in terms of power generation and substrate degradation. The pre-fermentation of waste facilitated lowering of activation losses and in turn increased the bio-electrochemical activity of biocatalyst, leading to an effective MFC performance. Fuel cell behavior with respect to polarization, anode potential and bio-electrochemical behavior also supported the performance of MFC with PFW. PFW operation showed higher catalytic current in voltammograms with fine catalytic peaks supporting the positive role of pre-fermentation in discharging electrons effectively. VFA and pH profiles also correlated well with power generation and substrate degradation pattern.

► Pre-fermentation of food waste (PFW) was applied to enhance the process efficiency. ► Single chambered mediator less microbial fuel cell (MFC) was used for evaluation. ► Pre-fermentation improved process efficiency and loading rate showed significant impact. ► Higher current with fine catalytic peaks were observed on voltammograms after pre-fermentation of waste.