Methane production enhancement and comparative study of biodegradation of some plants and animal wastes

Abstract

This study investigated the production of methane using various substrates. Plantain peels, pig dung, poultry droppings, walnut peels/plantain peels and cow blood/wheat waste were all co-digested, charged in digesters (A-E) and allowed to ferment anaerobically for forty-five (45) days within the mesophilic temperature range of 20.0-39.0°. Digester A contained 3.9 Kg of wheat waste/cow blood and 19.5 Kg of water in the ratio of 1.5 which gave a total gas yield of 22.5 L of biogas; B contained 7.8 Kg of walnut peels/plantain peels and 15.6 Kg of water in the ratio 1:2 which gave a total gas yield of 115.0 L; C contained 8 Kg of plantain peels and 16 Kg of water which yielded 133.0 L of biogas; D contained 8 Kg of pig dung mixed thoroughly with 16 Kg of water which gave a total of 321.0 L; and E contained 8 Kg of poultry droppings mixed with 16 Kg of water which yielded 168.5 L of biogas. From the cumulative comparison of the biogas yields of the samples, pig dung gave the highest yield of 321 L and cow blood/wheat husk produced the lowest yield of 22.5 L. Pig dung (animal waste) gave the highest total viable count (TVC) of 7 × 10⁶ cfu/mL. The sludge contains NPK which is a good biofertilizer.