Enhancement of methane production from waste activated sludge using hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) process – A review. (February 2022)

• Record Type: Journal Article
• Authors: Wang, Xue-Ting; Zhang, Yi-Feng; Wang, Bo; Wang, Song; Xing, Xue; Xu, Xi-Jun; Liu, Wen-Zong; Ren, Nan-Qi; Lee, Duu-Jong; Chen, Chuan
• Is Part Of: Bioresource technology. Volume 346(2022)
• Publication Date: 2022-02
• Subjects: Methane production -- Waste activated sludge -- Microbial electrolysis cell -- Anaerobic digestion -- Enhancing mechanism -- Microbial community; 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.2021.126641
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: CH4 is the main product of WAS anaerobic digestion. The poor WAS utilization and acid accumulation limited CH4 recovery. Microbial electrolysis cell is a prospective technology for CH4 production. MEC-AD could achieve substantial technical and economic benefits. Abstract: Hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) was proved to increase methane productivity and methane yield of waste activated sludge (WAS) by establishing direct interspecies electron transfer method and enriching functional microorganisms. This review first summarized the pretreatment methods of WAS for MEC-AD and then reviewed the reactor configurations, operation parameters, and the economic benefit of MEC-AD. Furthermore, the enhancement mechanisms of MEC-AD were reviewed based on the analysis of thermodynamics and microbial community. It was found that the decrease of hydrogen partial pressure due to the hydrogenotrophic methanogens enriched in cathodic biofilm and direct interspecies electron transfer between exoelectrogens and anode were the core mechanisms for improving acidogenesis, acetogenesis, and methanogenesis. Finally, the potentially technological issues that need to be addressed to increase energy efficiency in large-scale MEC-AD processes were discussed.