Effect of Biochar Application on Biogas Production From Cattle Paunch Content

Indiscriminate disposal of cattle paunch content by meat processing factories (abattoirs) to the surrounding environments as a result of poor regulation has constituted serious environmental pollution. To address this issue, this study employs the use of sorghum stalk biochar application for anaerobic digestion of paunch content. This research study was therefore designed to determine the effects of one-time addition and periodic addition of sorghum stalk biochar to the paunch content for enhanced biogas production. The design used was 5 g of one-time biochar addition to a digester, 1 g of biochar addition to a digester periodically at four day intervals, and a control digester. The digestion was carried out in a 1000 mL digester bottle with replicates. The biogas yields were 22.79 mL/g V S, 13.83 mL/g V S, and 11.67 mL/g V S for 5 g of one-time biochar addition, 1 g of periodic biochar addition, and control, respectively. Thus, the 5 g one-time biochar addition gives a better yield than the other two treatments. The test for significant difference between pairs of treatments shows that there is a significant difference between 5 g one-time biochar addition and 1 g periodic addition of biochar, and 5 g one-time biochar addition and control at the 5% level of significance. There was no significant difference between 1 g of periodic addition of biochar and the control. The experimental data of the three treatments were fitted to the Gompertz model, which shows adequate fit with <i>R</i> ² values of 0.991, 0.969, and 0.990 for 5 g one-time biochar addition, 1 g periodic biochar addition, and control, respectively.