Methane in wastewater treatment plants: status, characteristics, and bioconversion feasibility by methane oxidizing bacteria for high value-added chemicals production and wastewater treatment

Methane is a type of renewable fuel that can generate many types of high value-added chemicals, how -ever, besides heat and power production, there is little methane utilization in most of the wastewater treatment plants (WWTPs) all round the world currently. In this review, the status of methane production performance from WWTPs was firstly investigated. Subsequently, based on the identification and classifi-cation of methane oxidizing bacteria (MOB), the key enzymes and metabolic pathway of MOB were pre-sented in depth. Then the production, extraction and purification process of high value-added chemicals, including methanol, ectoine, biofuel, bioplastic, methane protein and extracellular polysaccharides, were introduced in detail, which was conducive to understand the bioconversion process of methane. Finally, the use of methane in wastewater treatment process, including nitrogen removal, emerging contaminants removal as well as resource recovery was extensively explored. These findings could provide guidance in the development of sustainable economy and environment, and facilitate biological methane conversion by using MOB in further attempts. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This review examines the methane production performance in wastewater treatment plants and delves into the key enzymes and metabolic pathways of methane oxidizing bacteria. It also discusses in detail the production, extraction, and purification processes of high value-added chemicals, as well as the utilization of methane in wastewater treatment processes. These findings aim to provide guidance for sustainable economic development and environmental protection through biological methane conversion.