Modeling and validation of single-chamber microbial fuel cell cathode biofilm growth and response to oxidant gas composition

• Published in: Journal of power sources 2016-10, Vol.328 (C), p.385-396
• Main Authors: Ou, Shiqi, Zhao, Yi, Aaron, Douglas S., Regan, John M., Mench, Matthew M.
• Format: Article
• Language: English
• Subjects: BASIC BIOLOGICAL SCIENCES; Cathodic biofilm growth; High performance computing; MATHEMATICS AND COMPUTING; Microbial fuel cell; Oxygen transport; Transient model
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.08.007

This work describes experiments and computational simulations to analyze single-chamber, air-cathode microbial fuel cell (MFC) performance and cathodic limitations in terms of current generation, power output, mass transport, biomass competition, and biofilm growth. Steady-state and transient cathode models were developed and experimentally validated. Two cathode gas mixtures were used to explore oxygen transport in the cathode: the MFCs exposed to a helium-oxygen mixture (heliox) produced higher current and power output than the group of MFCs exposed to air or a nitrogen-oxygen mixture (nitrox), indicating a dependence on gas-phase transport in the cathode. Multi-substance transport, biological reactions, and electrochemical reactions in a multi-layer and multi-biomass cathode biofilm were also simulated in a transient model. The transient model described biofilm growth over 15 days while providing insight into mass transport and cathodic dissolved species concentration profiles during biofilm growth. Simulation results predict that the dissolved oxygen content and diffusion in the cathode are key parameters affecting the power output of the air-cathode MFC system, with greater oxygen content in the cathode resulting in increased power output and fully-matured biomass. •Experiments & modeling validate mass transport through the cathode materials.•Compared the performance of MFC by the oxygen concentration in heliox and nitrox.•High performance computing methods are applied for the transient model.•Electrochemical and multiple biomass reactions are applied into models with mass transport.