Mesophilic and Thermophilic Anaerobic Co-Digestion of Paper Waste and Chicken Manure

Student: Christopher Stephen Obuaku (Project, 2025)
Department of Microbiology
University of Uyo, Akwa Ibom State


Abstract

This research assessed the effects of different temperatures on biogas production during anaerobic co-digestion of paper waste and chicken manure. The substrates: paper waste (PW) and chicken manure (CM) were co-digested with cow dung as an inoculum in two sets of five (5) bioreactors operated under mesophilic (35 ± 1°C) and thermophilic (45 ± 1°C) condition. Mesophilic digesters were labelled Am, Bm, Cm, Dm and Em while thermophilic digesters were designated At, Bt, Ct, Dt and Et. Each reactor contained varying proportions of paper waste and chicken manure as follows; A (100%PW), B (80%PW: 20%CM), C (60%PW:40%CM), D (50%PW:50%CM) and E (100%CM). From the results, thermophilic AD boosted biogas production by 39.5%, 97.6%, 78.3% and 11.1% in reactor B, C, D and E respectively, while mesophilic AD boosted biogas production by 100% in reactor A. The microbial genera identified were; Bacillus, Corynebacterium, Lactobacillus, Micrococcus, Staphylococcus and Streptococcus. The total heterotrophic bacterial count for chicken manure, paper waste and cow dung were observed as follows; 1.93 105 CFU/g, 3.6 103 CFU/g and 1.12 105 CFU/g, respectively. The results showed that thermophilic AD favoured enhanced biogas production than mesophilic temperature.

Keywords
Waste management Anaerobic microorganisms - Temperature effects Sustainable waste