Evaluation of the Potential for Generating Biogas from Cattle Manure Through Bioaugmentation

Abstract

This study evaluated the potential for biogas production from anaerobic digestion of cattle manure using bioaugmentation in batch-type bioreactors. A completely randomized design was adopted, with four treatments and three replications: CM, cattle manure only, as control; CMI, cattle manure plus inoculum; CMI-3, cattle manure plus inoculum and 3 mL of bioremediation additive; and CMI-9, cattle manure plus inoculum and 9 mL of bioremediation additive. The inoculum originated from a UASB (Upflow Anaerobic Sludge Blanket) reactor used in the effluent treatment plant of a food industry. The bioremediation additive was a gel containing environmental bacterial spores composed of different concentrations of Bacillus megaterium, Bacillus mycoides, Bacillus amyloliquefaciens, and Bacillus thermoglucosidasius. Substrates were characterized by pH, dry mass, organic and inorganic dry mass, total organic carbonate/total inorganic carbonate ratio, and nutrient concentration. Biogas volume, gas characteristics, and gas concentrations were assessed. Data were analyzed by ANOVA and F tests, followed by Tukey’s test at 5% significance. Inoculum, alone or combined with bioremediation, improved biogas production, with 9 mL addition of bioremediator resulting in 55.40% methane.