Bioelectricity from students’ hostel waste water using microbial fuel cell

Abstract

Microbial fuel was constructed using two liter plastic transparent chambers representing the cathode and anode poles. The electrodes used were carbon and copper which were utilized in producing a carboncarbon and copper-copper fuel cells respectively. A 1% sodium chloride and 2% agar proton exchange membrane was used to connect both chambers of the fuel cells. Waste water generated from students’ hostel in Federal University of Technology Owerri [FUTO], Nigeria, was  used as the substrate for pitching both fuel cells. An initial voltage of 308 mV and 338 mV were recorded for both fuel cells. The voltage was monitored for 14 days. During this period a maximum of 0.81 V and 0.62 to 0.02 V were recorded for the copper–copper and carbon–carbon fuel cells, respectively. The voltage production resembled typical growth curve with the performance of the copper–copper fuel cell being better than the carbon – carbon fuel cell in consistency. When both fuel cells were connected in series, a combined voltage of 138 mV (1.38 V) was obtained indicating that arranging the cells in series yielded a maximum output. When the microbial biofilm of both electrodes were analyzed, the microbial population included both aerobic and anaerobic bacteria which included the following: Bacillus spp., Corynebacterium spp., Staphylococcus spp., Enterococcus spp. and Micrococcus spp. This research demonstrates that microorganisms have the capacity to produce electricity using domestic wastewater as substrate.

Keywords: Microbial fuel cell, growth curve, bioelectricity, wastewater, electrodes.