Anaerobic Digestion of Abattoir Waste: A Combined Strategy for Biogas and Biofertilizer Production, and Waste Management

Aims: The study was carried out to estimate the biogas and biofertilizer potential of cattle Paunch and assess the waste treatment efficiency of the Anaerobic Digestion process.

Place and Duration of Study: The study was carried out at the Department of Water Resources and Environmental Engineering, Ahmadu Bello University Zaria between March and August 2016.

Methodology: We digested paunch from the rumen of one cow anaerobically for 30 days. Biogas production was measured. The digestate compost was used in comparison with Urea to cultivate maize. The plant heights, Plant diameter, average growth rate, number of cobs and weight of cobs were the performance indicators. The results obtained for each parameter were subjected to a Two Way ANOVA at 95% Confidence level using Minitab 14.2 Statistical software. Physicochemical and microbial characteristics of the feedstock and digestate were used as indicators of the treatment efficiency.

Results: 0.61 m3 of biogas was produced over the retention time while the potential biogas production of one mature cow was estimated at 7.43 m3/year. A total of 14.7 kg of digestate compost was obtained and utilized for the maize production. The results of the ANOVA showed that there was significant difference between the treatments for all parameters with a P-value of .000 in each case. Only plant height showed significant different between plots with a P-value of .035. 53.13% percent reduction in Total solids was achieved by the anaerobic digestion process while the reduction in Volatile solids, Chemical Oxygen Demand, E. coli and Enterobacteriaceae were 47.12%, 29.10% 86.75% and 91.28% respectively while the overall efficiency was estimated at 63.86%.

Conclusion: Biogas in good quantity and compost was produced via the anaerobic digestion of cattle paunch and the process achieved over 60% waste treatment efficiency.