An explanation of the methanogenic pathway for methane production in anaerobic digestion of nitrogen-rich materials under mesophilic and thermophilic conditions. (September 2018)

• Record Type: Journal Article
• Authors: Yin, Dong-Min; Westerholm, Maria; Qiao, Wei; Bi, Shao-Jie; Wandera, Simon M.; Fan, Run; Jiang, Meng-Meng; Dong, Ren-Jie
• Is Part Of: Bioresource technology. Volume 264(2018)
• Page Start: 42
• Page End: 50
• Publication Date: 2018-09
• Subjects: Methanogenic pathway -- Free ammonia -- Microbial community -- Mesophilic -- Thermophilic; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2018.05.062
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Illustrations of the methanogenic pathways indicated by carbon isotope (δ 13 C) analysis under mesophilic and thermophilic conditions. Highlights: The Methanogenesis pathway was quantitatively determined by 2–13C isotope. SAO-HM account for 41% and 50% of methane formation at 37 °C and 55 °C. The thermophilic digester had 15% lower methane yield rates. Stable processes were achieved at free ammonia of 31 and 145 mg/L, respectively. Abstract: The impact of temperature on the anaerobic digestion of chicken manure was investigated by studying the process performance and pathway for continuously-fed digesters under mesophilic and thermophilic conditions. The mesophilic digester obtained a 15% higher methane yield compared with the thermophilic digester. Mesophilic and thermophilic digester had free ammonia of 31 and 145 mg/L, respectively. The stable carbon isotope analysis indicated that 41% and 50% of acetate was converted to methane through the syntrophic acetate oxidation and hydrogenotrophic methanogenesis (SAO-HM) pathway under mesophilic and thermophilic conditions, respectively. The genus Pseudomonas represented 10% and 16% under mesophilic and thermophilic conditions, respectively. A high abundance of the methanogens genus Methanoculleus (94% of total methanogens) in mesophilic and the genus Methanothermobacter (96%) in thermophilic digesters indicated they were the main hydrogenotrophic partners in SAO. The present study therefore illustrated that methanogenic pathway shifting, induced by free ammonia, closely correlated to the process performance.