Optimizing anaerobic digestion from chicken droppings: impact of inoculation with IL and IL-KT01 inoculums on specific biogas production

Anaerobic digestion is widely used to treat chicken droppings. This biological process has the advantage of producing biogas and fertilizer and could reduce the environmental impact of chicken manure. The aim of this study was to investigate the effect of inoculating chicken droppings with two inoculums, IL and IL-KT01, on biogas yield, methane content, and anaerobic digestion duration activity. Batch digesters fed with chicken droppings were inoculated with the two inoculums: IL (derived from the digestate of chicken droppings, horse dung, and cow dung), and IL-KT01 (IL bioaugmented with pure bacteria KT01) considering the substrate-to-inoculum ratio of 80:20. Anaerobic digestion lasted 40 days at 35 °C. The results showed that the chicken droppings anaerobic digestion time was shortened to 25 days instead of 40 days in comparison to the control (without inoculation with IL and IL-KT01), and the biogas production was improved in terms of quantity and quality in the case of inoculation with inoculum IL-KT01 compared to the control. Biogas yield reached 220 mL/g VS (68.5% CH₄) in the case of inoculum IL-KT01, compared to 94 mL/g VS in the case of digesters inoculated with inoculum IL, and 64 mL/g VS in the case of non-inoculated digesters.