Experimental Determination of Effect of Total Solid (TS) and Volatile Solid (VS) on Biogas Yield

In this research work, eight different samples of substrates with varying percentage total solid (TS) and volatile solid (VS) were used. The samples which comprises mainly of water hyacinth, waste water (i.e., from ice fish cold room, septic tanks, and abattoir), pig dung, cow dung, corn cobs, potato peels, pineapple peels, rice left over, yam peels, cassava peels, orange peels, sweet potato peels, garri left over, plantain peels, beans waste, banana peels and vegetables, etc., were co-digested. In each of the samples, 10kg of substrates were used and the experiment was conducted within mesophilic temperature range of 36°C-37°C, pH range of 6.9-7.4 and hydraulic retention time (HRT) of thirty-three (33) days. It was observed that the quantity of biogas yield from these substrates increase with increasing percentage volatile solid and decrease with decreasing percentage volatile solid concentration below and above the optimum value of 91.1% (2.88kg) volatile solids which gave the maximum amount of biogas yield for the samples of substrates to be 1.01kg (23.6%), 2.01kg (60.75%), 2.55kg (84.72%), 2.41kg (68.0%), 2.35kg (67.67%), 1.85kg (59.23%), 1.45kg (25.39%). Furthermore, the results obtained reveal that bio-digesters should be run at 10.16% total solids, since optimum cumulative biogas generation is achieved at this %TS concentration.