Membrane-less MFC based biosensor for monitoring wastewater quality

Microbial fuel cell (MFC), a bioelectrochemical device, can be used to produce bioelectric signals from hydrogen carriers, particularly organic compounds in wastewaters. The solid correlation between the signals and the hydrogen carrier concentration can be exploited in a biosensor for measuring wastewater quality. A small volume of the membrane-less SCMFCs were operated with various wastewater concentrations to investigate the relationship between the concentration of substrates with the current outputs and the performance of the SCMFCs. The results demonstrated that the detection times of current outputs from low to high peak were significantly short when using a low synthetic wastewater (SW) concentration of 25–1000 mg COD.L^?1. The correlation between the SW concentration and the current outputs was obtained up to 250 mg COD.L^?1 (R² = 0.96). When the SCMFCs were fed with distillery wastewater (DW) from low to high concentration (50–2000 mg COD.L^?1), it showed a detection times of the current as short. SCMFCs had a good correlation between the concentration of DW and the current outputs obtained up to 1200 mg COD.L^?1 (R² = 0.97). Maximum substrate reduction was found more than 90% when the initial SW concentration was in the range of 25–1000 mg COD.L^?1. While substrate reduction was more than 60% for the DW concentration in the range of 50–2000 mg COD, L^?1 was operated. In other words, this membrane-less SCMFCs are able to be a long starvation (5 days) and a high repeatability of the current output in both wastewaters. Indications proved that the detection time of current and substrate degradation were dependant on concentrations, types of substrate, and types of MFC.