Converting the energy contained in human excreta into electricity using a modular Microbial Fuel Cell (MFC) designed to retrofit existing composting latrines.
The Microbial Fuel Cell (MFC) Latrine has been demonstrated as viable sanitation technology . Built with community resources, our MFC Latrine is a low-cost, low maintenance toilet that directly converts the potential energy contained in human waste (human excreta) into electricity, while simultaneously removing the organic matter and nutrients that deteriorate can pollute ecosytems and allow pathogens to persist in water sources .
A microbial fuel cell (MFC) latrine that treats human waste and produces compost and electricity was deployed in Agona Nyakrom, Ghana . After solid wastes were composted, the MFC treated organic matter and nitrogen from the remaining liquid stream. Organic matter was oxidized in the anode by anode-respiring bacteria that transfer electrons to an external circuit, producing electricity, which was observed to be 268 nW/m2 after two years of operation. A separate nitrification stage transformed ammonium present in urine, to nitrate. Nitrate was reduced to nitrogen gas by cathode-oxidizing bacteria in the cathode completing nitrogen removal. The MFC Latrine was constructed on-site using local labor and materials. Evidence of total nitrogen removal and power production was observed while the MFC Latrine was in operation. Multiple user challenges and maintenance affected the performance, yielding low power output. The initial findings suggest that the viability of the system is directly correlated with its use. Incorporating the MFC Latrine system into the user community's typical social practices is key to a successful deployment of the MFC Latrine as a sanitation technology.
Bill & Melinda Gates Foundation Energy: electricity, hydrogen, fuel cells Fundamental research and engineering Global North America Product design and engineering Resource recovery University, education or research institution
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danijela milosevic (milli)
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