Influence of Inoculum Type on Biogas Production from Paper Waste and Chicken Manure

Anaerobic digestion, a biological process that converts organic materials into biogas, is influenced by the type of inoculum used, as it contains the microbial community essential for the process. This research aimed to optimise biogas production from paper waste and chicken manure by investigating the influence of inoculum type on yield and process stability. The efficiency of three inoculum sources: cow dung, rumen fluid, and goat dung were compared under four varying mixing ratios (digester A - PW25:CM75, digester B - PW35:CM65, digester C - PW65:CM35, and digester D - PW75:CM25), with paper waste serving as substrate and chicken manure as co-substrate. The retention period of the anaerobic digestion was 30 days. Maximum cumulative biogas production (750mL/gVS) was achieved in the codigestion of paper waste and chicken manure with the inoculum rumen fluid in digester A. Goat dung also had the maximum cumulative biogas yield in digester B (745mL/gVS), C (630mL/gVS), and D (455mL/gVS). Six probable bacterial isolates were identified and consisted of Bacillus, Staphylococcus, Corynebacterium, Enterobacter, Escherichia, and Pseudomonas sp. Staphylococcus sp had the most prevalent occurrence (40%). Generally, rumen fluid produced more biogas in digester A than cow dung and goat dung as a result of the variety of bacteria supplied and also by the influence of the mixing ratio, and goat dung produced more biogas in digester B, C, and D because it had more readily degradable organic matter. Careful selection of inoculum for biogas production is recommended for optimal biogas production.