Enhancement of methane production from waste activated sludge using hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) process – A review
Journal
Bioresource Technology
Journal Volume
346
Date Issued
2022
Author(s)
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. ? 2021 Elsevier Ltd
Subjects
Anaerobic digestion
Enhancing mechanism
Methane production
Microbial community
Microbial electrolysis cell
Waste activated sludge
methane
anaerobic growth
bioreactor
electrolysis
sewage
Anaerobiosis
Bioreactors
Electrolysis
Methane
Sewage
Type
review