MESOPHILIC CO-DIGESTION OF CATTLE PAUNCH WITH POULTRY DROPPINGS: MIXTURE EFFECT ASSESSMENT ON BIOGAS PRODUCTION POTENTIALS

Abstract

Cattle paunch and poultry droppings are wastes that have posed environmental hazards due to poor management and disposal strategies in most municipal abattoirs and livestock farms in Nigeria. Utilization of these wastes for energy production at small and/or large scale requires assessment to ascertain the optimal mix. This study is therefore designed to determine the optimal mixing ratio and its effect on biogas production potentials of cattle paunch and poultry droppings under tropical condition. The fermentation was carried out in 30 litres batch type digesters with 60 days retention period. The single and mixing ratios of cattle paunch  and Poultry droppings  assessed were: 100: 0, 75: 25, 65: 35, 50: 50, 35:65, 25:75 and 0:100 labeled D1, D2, D3, D4, D5, D6, and D7 respectively. From the study, the mixture effect assessment of cattle paunch co-digested with poultry droppings shows that three digesters had highest cumulative biogas production potential in the range of 35% to 65% of cattle paunch co-digested with 35% to 65% of poultry droppings which are D3 (65% CP + 35% PD) , D4 (50% CP + 50% PD), and D5 (35% CP + 65% PD). On further assessment using anaerobic biomass indicator and technical digestion time assessment criteria, digester D4 (50% CP + 50% PD) was recommended as the optimal mix.