Sustainable Hypersaline Microbial Fuel Cells: Inexpensive Recyclable Polymer Supports for Carbon Nanotube Conductive Paint Anodes

Abstract

Microbial fuel cells are an emerging technology for wastewater treatment, but to be commercially viable and sustainable, the electrode materials must be inexpensive, recyclable, and reliable. In this study, recyclable polymeric supports were explored for the development of anode electrodes to be applied in single-chamber microbial fuel cells operated in field under hypersaline conditions. The support was covered with a carbon nanotube (CNT) based conductive paint, and biofilms were able to colonize the electrodes. The single-chamber microbial fuel cells with Pt-free cathodes delivered a reproducible power output after 15 days of operation to achieve 12±1 mW m at a current density of 69±7 mA m . The decrease of the performance in long-term experiments was mostly related to inorganic precipitates on the cathode electrode and did not affect the performance of the anode, as shown by experiments in which the cathode was replaced and the fuel cell performance was regenerated. The results of these studies show the feasibility of polymeric supports coated with CNT-based paint for microbial fuel cell applications.

Enhancement of microbial fuel cell performance by introducing a nano-composite cathode catalyst

“…Compared to PGM catalysts, PGM-free catalysts are more resistant towards poisoning [ [59] , [60] , [61] ] and much lower cost to be used in MFC [ 62 , 63 ]. Carbonaceous-based materials such as activated carbon (AC) [ [64] , [65] , [66] , [67] , [68] , [69] ], carbon nanotubes (CNT) [ 70 ], carbon nanofibers (CNF) [ 71 ], 2D or 3D-graphene nanosheets [ 72 ], etc. [ 73 ] were also used as cathode materials due to their low-cost, high surface area, relatively high conductivity and durability in “harsh” and polluted environments.…”

Alginate‐Encapsulated Bacteria for the Treatment of Hypersaline Solutions in Microbial Fuel Cells

“…Recently, a mixed consortium of halotolerant bacteria isolated from the Great Salt Lake (GSL, Utah) was utilized in our group to develop MFCs operating at a salinity close to 100 g L −1 , with the electrolyte composed of 50 % real lake solution (total salt content (140±20) g L −1 ) and 50 % synthetic solution (35 g L −1 NaCl). The developed MFCs achieved a maximum power output of 42 mW m −2 when carbon cloth anodes were utilized (based on anode surface area) and 16 mW m −2 when carbon‐nanotube‐modified polymeric support was used as a cost‐effective and resistant anode material . These initial works aimed to determine whether the obtained bacterial samples could be used as a source of electroactive halotolerant bacteria.…”

Efficient In Situ Utilization of Caustic for Sequential Recovery and Separation of Sn, Fe, and Cu in Microbial Fuel Cells

“…The diffusional resistance ( R d ) in all three cathodes was significantly higher than the R s and the R ct , and increased with different extents over time (Table S1), likely due to mass transfer limitations with the formation of the metal precipitates on the electrode. This increased resistance has also be shown in other studies with W and Mo deposited on stainless steel sheet cathodes in bioelectrochemical systems, Cd deposits on carbon rods or titanium sheets in cathodes of microbial electrolysis cells, and even inorganic precipitates on Pt‐free cathodes of MFCs …”