title: Biogas production from undiluted chicken manure and maize silage: A study of ammonia inhibition in high solids anaerobic digestion.
abstract: The feasibility of co-digestion of chicken manure (CM) and maize silage (MS) without water dilution was investigated in 5-L digesters. Specific methane production (SMP) of 0.309LCH4g(-1) volatile solids (VS) was achieved but only at lower %CM. Above a critical threshold for total ammonia nitrogen (TAN), estimated at 7gNL(-1), VFA accumulated with a characteristic increase in acetic acid followed by its reduction and an increase in propionic acid. During this transition the predominant methanogenic pathway was hydrogenotrophic. Methanogenesis was completely inhibited at TAN of 9gNL(-1). The low digestibility of the mixed feedstock led to a rise in digestate TS and a reduction in SMP over the 297-day experimental period. Methanogenesis appeared to be failing in one digester but was recovered by reducing the %CM. Co-digestion was feasible with CM ⩽20% of feedstock VS, and the main limiting factor was ammonia inhibition.
authors.affiliation: Biomass Energy Engineering Research Centre, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China; Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK; Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Chen
authors.initials: C
authors.lastname: Sun
authors.affiliation: Biomass Energy Engineering Research Centre, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China; Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Weixing
authors.initials: W
authors.lastname: Cao
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Banks
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK.
authors.forename: Sonia
authors.initials: S
authors.lastname: Heaven
authors.affiliation: Biomass Energy Engineering Research Centre, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China; Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK; Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, 800 Dongchuan Road, Shanghai 200240, People's Republic of China. Electronic address: liurhou@sjtu.edu.cn.
authors.forename: Ronghou
authors.initials: R
authors.lastname: Liu
mesh_terms: D000641:Ammonia; D000693:Anaerobiosis; D000818:Animals; D056804:Biofuels / Q000032:analysis; D019149:Bioreactors; D002645:Chickens; D004063:Digestion; D008372:Manure; D008697:Methane / Q000096:biosynthesis; D012820:Silage; D018505:Waste Management / Q000379:methods; D014866:Waste Products; D003313:Zea mays
chemical_list: D056804:Biofuels; D008372:Manure; D014866:Waste Products; D000641:Ammonia; D008697:Methane
keywords: Ammonia inhibition; Chicken manure; Isotope tracing; Mesophilic anaerobic digestion; Methanogenic pathway