Sodium hypochlorite induced inhibition in anaerobic digestion and possible approach to maintain methane fermentation performance

• Published in: Bioresource technology Vol. 352; p. 127096
• Main Authors: Ni, Jialing, Ji, Jiayuan, Kubota, Kengo, Li, Yu-You
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-05-2022
• Subjects: Anaerobic membrane bioreactor; Anaerobiosis; Bacteria; Bioreactors - microbiology; Fermentation; Membrane cleaning chemicals; Membrane fouling; Methane; Microbial community; Sodium hypochlorite; Sodium Hypochlorite - pharmacology; Sodium hypochlorite; Membrane cleaning chemicals; Anaerobic membrane bioreactor; Membrane fouling; Microbial community
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.127096

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•Effect of NaClO concentrations on anaerobic digestion was investigated at 0–9 g/L.•Biogas production performance was unaffected when the NaClO was below 3 g/L.•Microbial products recovered the microbial activity at an 10 g/L NaClO concentration.•The association of major bacterial genera was investigated via correlation analysis.•OTUs most affected by NaClO mainly belonged to coryneform and filamentous bacteria.
Since sodium hypochlorite (NaClO), a commonly used chemical to deal with membrane fouling, is toxic to microorganisms, it is a major concern in the membrane cleaning process. In this study, the concentration-dependent effects of NaClO (0–9 g/L) on the biodegradation performance and microbial activity were investigated via batch experiments. The methane production (obtained approximately 140 mL) and microbial community revealed by principal coordinates analysis were almost unaffected when the NaClO concentration ranged between 0 and 3 g/L. A follow-up batch experiment was conducted and revealed that the microbial products could help protect or recover the activity of anaerobic microorganisms at a high NaClO concentration of 10 g/L. Additionally, correlation analysis was used to investigate the associations between the 15 major bacterial genera. Moreover, the microbial analysis results indicated that the top 10 operational taxonomic units most affected by NaClO were primarily coryneform and filamentous bacteria.