Thermal And Chemical Pre-Treatments Of Cow Dung And Poultry Litter Enhance Biogas Production In Batch Fermentation

Abstract Low degradability of substrates is one of the factors that hinder the production of biogas. With the aim of maximizing biogas yields from cow dung CD and poultry litter PL a series of experiments were carried out under mesophilic conditions at 38 C using batch digester operating for 21 days hydraulic retention time HRT. Temperature pre-treatment at 60 and 80 C and chemical pre-treatment with NaOH 0.45 g 1.35 g and 2.25 g were applied as a pre-treatment. Cumulative biogas production and VS reduction from anaerobic digestion of 80 C pre-treated substrate was 46.3 and 26.1 higher than the control respectively. However thermal pre-treatment at 60 and 80 C did not show statistically significant difference in biogas production. Biogas yields of substrates that received 0.45 g 1.35 g and 2.25 g of NaOH increased biogas production by 0.03 21 and 56 over that of the control respectively. Overall results indicated that the biogas yield and VS and TS reduction can be enhanced through thermal and chemical pre-treatments prior to anaerobic digestion.