EVALUATION OF PIG DUNG FOR THE GENERATION OF ELECTRICAL CURRENT USING MICROBIAL FUEL CELL

Abstract

Pig dung was evaluated for electric current and voltage generation using microbial fuel cell (MFC). Pig dung was collected from three different animal farms; Federal University of Technology, Akure, Air Force and Apatapiti Extension. Isolation and identification of microorganisms from pig dung was carried out before and after electric current and voltage generation using conventional techniques. Proximate and mineral composition were determined using standard methods. MFC was constructed with 1200 ml capacity plastic containers. This study was evaluated in three categories as; pig dung based MFCs, bacteria based MFCs and fungi based MFCs. Current and voltage were measured in the morning, afternoon and evening for 40 days using the digital multimeter. Organisms with the highest occurring frequency before and after the generation period were further used for electric current and voltage generation in monoculture and co culture. Twenty-seven (27) bacteria and six (6) fungi were identified. Air Force pig dung had the highest bacteria load (2.71 x 105 cfu/g) while FUTA pig dung had the highest fungal load (1.47 x 104 sfu/g) before current and voltage generation. Apatapiti Extension pig dung had the highest bacteria load (1.35 x 105 cfu/g) while FUTA pig dung had the highest fungal load (1.60 x 104 sfu/g) after current and voltage generation The highest occurring organisms from the study include Paenibacillus amylolyticus (24 %), Yersinia intermedia (17.24 %), Bacillus mycoides (16.67 %), Aspergillus funmigatus (55.56 %), Aspergillus flavus (52.94 %) and Fusarium sp (50 %). MFC- KMnO4 generated higher voltage and current throughout the study. The highest voltage and current from the pig dung based MFCs were generated from MFC- KMnO4 of FUTA in the evening of day 7 with a value of 1301 mV and from MFC- KMnO4 of Apatapiti Extension in the evening of day 8 with a value of 4.502 mA respectively. The highest voltage and current from the bacteria based MFCs were generated from MFC- KMnO4 of Yersinia enterocolitica in the morning of day 9 with a value of 1334.00 mV and in the afternoon of day 7 with a value of 4.190 mA respectively. The highest current and voltage from the fungi based MFCs were generated from MFC- KMnO4 of Aspergillus tamarii in the morning of day 8 with a value of 1420.33 and from MFC- KMnO4 of Fusarium verticillioides in the afternoon of day 1 with a value of 2.51 mA respectively. Serial connection of the pig dung based MFCs, bacteria based MFCs and fungi based MFCs generated a combined voltage of 3003 mV, 3290 mV and 5300 mV respectively. This was able to power light emitting diode (LED) bulbs (red and yellow) and wall clock. The use of pig dung for electric current generation is therefore, a potential solution to resolving the problems of environmental toxics, air pollution and health hazards that oozes from its disposal and will ultimately serve as a way of mitigating global warming in the world.