Abstract

Cassava peels (CP) obtained after peeling cassava roots were anaerobically digested using 50L capacity fermentor and in blends with some animal wastes. The peels were blended with cow dung (CD), poultry droppings (PD) and swine dung (SD), in the ratio of 1:1. The mean flammable biogas yield of the cassava peels alone was 2.29 ± 0.97L /total mass of slurry. When blended with CD, PD and SD, mean flammable biogas yield was increased to 4.88 ± 1.73, 5.55 ± 2.17 and 5.65 ± 2.62 L /total mass of slurry respectively. Flammable biogas was produced by CP alone from the 59^th day of the digestion period. The CP: CD and CP: PD produced flammable gas from the 9^th day whereas CP: SD started flammable gas production from the 11^th day. While the CP: SD had the highest cumulative gas yield of 169.60L/total mass of slurry, the CP: CD experienced fastest onset of flammable gas production. Overall results indicate that the relatively low flammable biogas production and slow onset of gas flammability of cassava peels can be significantly enhanced when combined with the animal wastes in definite proportions.

Key words: Cassava peels, biogas production, flammable gas production, waste blends, biogas yield.