New Cell Design Improves Performance of a Microbial Fuel Cell in the Treatment of Leachates from the Dark Hydrogenogenic Fermentation of Organic Solid Wastes

Improvement of Microbial Fuel Cell Performance by Selection of Anodic Materials and Enrichment of Inoculum

“…To the best of our knowledge studies on leachate treatment in MFCs seeded with enriched inocula are very scarce in the open literature [49]. There are, however, a couple of articles of our own group that deals with leachate treatment in MFC using more conventional inocula (aerobic, methanogenic, sulphate-reducing consortia) as well as research carried out by others whose results in general show low powers and moderate to adequate pollutant concentration removal (as chemical oxygen demand (COD)) (see review in appendix A, Supporting Information (SI)) [5,6,[50][51][52][53].…”

“…For instance, in biohydrogen production from dark fermentation of organic wastes, the complete conversion of wastes to energy is not possible [3]. Dark fermentation typically leads to partial degradation of the organic matter; a large amount of organic metabolites still remain in the spent liquors or leachates of dark fermentation that can be used as "fuels" in microbial fuel cells (MFCs) [4][5][6].…”

“…In this context, MFCs have emerged as a promising process for sustainable production of low intensity electrical energy and treatment of wastes such as the leachates and liquors of biohydrogen dark fermentation, thus constituting key contributors to sustainable development of our societies in the near future [7]. A MFC is an bioelectrochemical device that is capable of converting organic matter into electricity [5,6,[8][9][10]. However, there are still some bottlenecks that can affect the electric energy production in a *To whom correspondence should be addressed: Email: r4cepe@yahoo.com Phone: 52 MFC, such as the nature of the biocatalysts, the type and materials of electrodes, electrode catalysts, cell configuration, and architecture, among others [11][12][13][14].…”

“…A good anodic material should have the following properties: high electrical conductivity, strong biocompatibility, chemical stability and anti-corrosion, large surface area and appropriate mechanical strength and toughness [14,15]. Thus, in order to reduce the R int of the cell some materials and designs have been evaluated, such as new anodic materials, replacement of the salt bridge by membranes, choosing membranes with high protonic conductivity or building membrane-less MFC, increasing solution conductivity and reducing the pH, reducing electrode spacing, among others [5,6,[25][26][27][28][29][30][31]. Regarding the effect of anodic materials, there has been much research on the use of graphite anodes in MFC [12][13][14][15][30][31][32][33][34][35][36][37][38][39][40].…”

“…However, for practical applications in MFC, pure cultures do not seem to be a good option because of expensive sterilization of the influent and equipment is typically required. Instead of pure cultures, microbial mixed cultures or consortia from brewery wastewater, activated sludge, marine sediments, methanogenic and sulfate-reducing cultures, domestic wastewater and preacclimated bacteria from an active MFC could be used as inocula [6,24,42,43].…”