Combined effects of liquid digestate recirculation and biochar on methane yield, enzyme activity, and microbial community during semi-continuous anaerobic digestion. (November 2022)

• Record Type: Journal Article
• Authors: Shao, Zhijiang; Chen, Heyu; Zhao, Zhuangzhuang; Yang, Zaijun; Qiu, Ling; Guo, Xiaohui
• Is Part Of: Bioresource technology. Volume 364(2022)
• Publication Date: 2022-11
• Subjects: Biogas slurry -- Swine manure -- Biochar application -- Organic loading rate -- Methanogenic pathway; 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.2022.128042
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: LDR improved the system stability and load limit with carbon-rich feedstock. Biochar reserved the methane concentration over LDR before failure. Typical enzyme activities involved in AD process were enhanced. LDR enhanced acetoclastic pathways of methanogenesis. Co-application of LDR and biochar shaped the microbial community structures. Abstract: The combined effects of liquid digestate recirculation (LDR) and biochar on methanogenesis and microbial communities were studied in semi-continuous anaerobic reactors fed with wheat straw and swine manure. The tolerated organic loading rate (OLR) was expanded from 5 g- volatile solids (VS)∙L -1 ∙d -1 in the control to higher than 6 g-VS∙L -1 ∙d -1 in the LDR. At the OLR of 5.0 g-VS∙L -1 ∙d -1, average special methane yield in LDR with biochar was 0.234 L∙g-VS -1, which was 5.4 % higher than that of the LDR alone. Moreover, enzyme activity and microbial community analysis indicated that LDR with biochar enhanced the processes of hydrolysis and methanogenesis, and balanced the pathway between hydrogenotrophic and acetoclastic methanogenesis. The co-application of LDR and biochar synergistically enhanced the degradation pathways of substrates and the loading shock resistance of anaerobic digestion system. This study could offer strategies for developing sustainable applications of full and continuous LDR in industrial biogas projects.