Mesophillic Anaerobic Co-Digestion of Horse Dung, Plantain Peel and Egg Sheel at Different Climatic Conditions

Abstract

This study centered on biogas production from locally available animal and kitchen wastes: horse dung (HD), plantain peel (PP) and egg shell (ES) using five 32-Litres metallic prototype digesters. The anaerobic digestion was in the ratio of 3:1 of water to waste for all the samples as follows: Sample A was 100%HD, Sample B; 100% PP, Sample C; 100% ES, Sample D; 50%HD+50%PP and Sample E; 60% HD+30% ES+10% PP. The retention time was 30 days. Parameters like pH, daily biogas production, ambient and slurry temperatures, solar radiation, wind speed, air temperature alongside the physico-chemical properties of wastes were monitored. The cumulative gas production yield was 81.8L, 22.3L, 51.9L, 109L, and 75.2L for samples A, B, C, D and E respectively. The flammable time was 10th, 13th, 16th, 6th, 10th day for samples A, B, C, D and E respectively. The result revealed that sample D: 50%HD+50%PP gave the highest yield of biogas (109L) and flamed earlier than the other samples (6 days) while sample B: 100%PP had the lowest yield of biogas (22.3L). The results also showed that the sample that had the highest composition of methane in the biogas produced was Sample C: 100%ES with 90.3995% while the lowest composition of methane was found in Sample B: 100%PP to be 79.9963%. The TS and VS were seen to be consistently reducing while TVC and BOD reduced (immediately the microbes got acclimatized to the environment) showing the level of waste treatment achieved during the digestion period of 30 days.