Alleviating "inhibited steady-state" in anaerobic digestion of poultry manure by bentonite amendment: Performance evaluation and microbial mechanism. (September 2022)

• Record Type: Journal Article
• Authors: Ma, Junyi; Pan, Junting; Zhang, Yulei; Yao, Zonglu; Yu, Jiadong; Luo, Juan; Shen, Ruixia; Awasthi, Mukesh Kumar; Zhao, Lixin
• Is Part Of: Bioresource technology. Volume 360(2022)
• Publication Date: 2022-09
• Subjects: Semi-continuous anaerobic digestion -- Inhibited steady-state -- Bentonite -- Exogenetic electron mediator -- Methane production; 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.2022.127519
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Bentonite maintained methanogenic stability under an "inhibited steady-state". Bentonite increased Sedimentibacter and Syntrophomonas abundance by 110% and 91%. Methanosarcina dominated methanogenesis when suffering from ammonia stress. Bentonite triggered a more robust syntrophic acetate oxidizing methanogenesis. Abstract: This study systematically evaluated the effects of bentonite as a possible additive to alleviate the "inhibited steady-state" induced by ammonia and acid accumulation during anaerobic digestion. Continuous stirred tank reactors fed with poultry manure were operated at 35 ± 1 °C either with bentonite or not. The results demonstrate that bentonite amendment increased average specific methane production by 35% as suffered from steady-state at an organic loading rate of 6.25 g VS/L·d. 16S rRNA gene amplicon sequencing revealed that the relative abundance of electron-donating Sedimentibacter and Syntrophomonas, and electrophilic Methanosarcina was increased by 110%, 91%, and 49%, respectively. The genera were identified as crucial for alleviating "inhibited steady-state", through establishment of a more robust syntrophic pathway of methanogenic acetate degradation. The enhancement might result from the accelerated electron transfer by bentonite, which is qualified for serving as an exogenetic electron mediator due to containing abundant redox-active metal elements.