Engineering of Microbial Fuel Cells: The Things We Need to Know to Move Forward

Microbial fuel cells (MFCs) provide a unique opportunity to combine the advantages of two worlds, wastewater purification and electricity production, that can be successfully explored for the development of self-sustainable portable wastewater plants. Unfortunately the level of development of this technology is just heading into the list of the practical devices. A significant part of the efforts in this area has been associated with fundamental understanding of the operational laws behind MFCs. Now, when the pile of knowledge regarding biofilm formation, electrode respiration by bacteria, biological interfacial reactions, etc. reached significant level, the next step in the scale-up process should involve material and design optimization. By looking back at what has been developed so far using innovative statistical interpretation of data, a numerous conclusions regarding bacteria features, metabolic pathways, electrode characteristics and MFC design can be withdrawn. Based on these conclusions, and mainly based on the observed correlation between parameters, a model describing MFC operation was created. This model included sub-modules describing the bacterial community, bacteria-electrode interactions, material properties as well as MFC overall design parameters^[1].

 The major factors influencing MFCs was recognized through Principal component analysis and their ascendency over MFC operational characteristics was statistically evaluated. The outputs of this analysis were further used as inputs for the development of a mathematical model, combining those factors. Path analysis was the main analytical tool for the model establishment. The model was first developed for pure culture of Shewanella oneidensis and expanded to include mixed communities naturally occurring in wastewater, which makes this study unique.  

 Successful engineering of MFCs, or other bioenergy systems, requires understanding of the underlying physical and biological processes, materials and abiotic structures, and the technical limits of their implementation in practical devices. This presentation will chart our strategies in bioenergy device design at all these four technology levels.

 [1] a) S. Babanova, O. Bretschger, J. N. Roy, A. Cheung, K. Artyushkova and P. Atanassov, Phis.Chem.Chem.Phys. 2014, doi: 10.1039/C4CP00566J; b) C. Santoro, M. Guilizzoni, J.P. Correa Baena, U. Pasaogullari, A. Casalegno, B. Li, S. Babanova, K. Artyushkova, P. Atanassov, Carbon 2014, 67, 128–139.