Improving biomethane fermentation through trace elements-driven microbial changes: Different effects of Fe0 combined with Co/Ni. (October 2022)

• Record Type: Journal Article
• Authors: Li, Jiang; Lei, Yunhui; Pu, Xiaodong; Liu, Yi; Mei, Zili; Tang, Ya
• Is Part Of: Process biochemistry. Volume 121(2022)
• Page Start: 197
• Page End: 206
• Publication Date: 2022-10
• Subjects: Trace elements -- Vegetable waste -- Anaerobic digestion -- Acid inhibition -- Microbial community; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2022.07.004
• Languages: English
• ISSNs: 1359-5113

Abstract

Abstract: Anaerobic digestion at high organic loading rate (OLR) is prone to acid inhibition that reduces methane production. In this study, effects of Fe 0 (+Co/Ni) on suppressing acid inhibition and improving methane production were studied using vegetable waste as substrate at OLR of 3.0 gVS/L/d for 160 days. Results indicated additional use of Co/Ni with Fe 0 did not further improve the effects of Fe 0 and use of Ni suppressed considerable the effects of Fe 0 . These differences were supported by microbial changes caused by addition of Fe 0 (+Co/Ni). Analysis of 16S rRNA genes revealed microbial community without Ni addition was more stable, a factor largely influenced by pH and ammonia nitrogen levels. Relative abundances of Methanosarcina and Methanosaeta were approximately 60% in Fe 0 -Ni and Fe 0 -Co-Ni treatments, and 90% in control, Fe 0 and Fe 0 -Co treatments. But linear discriminant analysis effect size and network analysis indicated Methanosaeta and Methanosphaera, not Methanosarcina, were key methanogens. They functioned with acid producing Acetobacterium, and ammonia nitrogen producing Aminobacterium to convert volatile fatty acids to methane in Fe 0 treatments. Actinomyces were key microorganisms that hindered methanogenesis, especially in Ni addition treatments. This work suggests addition of Fe 0 in anaerobic digestion at high OLR is theoretically feasible for engineering applications. Graphical Abstract: ga1 Highlights: Effects of Fe 0 (+Co/Ni) in methane fermentation at high OLR were investigated. Fe 0 maintained 215–250 mLmethane /gVS/d and suppressed acid inhibition. Ni weakened or minimized promoting effect of Fe 0 . Methanosaeta and Methanosphaera, not Methanosarcina were the key methanogens. Aminobacterium and Acetobacterium promoted while Actinomyces hindered MPR.