A Scoping Review of Options for Increasing Biogas Production from Sewage Sludge: Challenges and Opportunities for Enhancing Energy Self-Sufficiency in Wastewater Treatment Plants

Treating municipal wastewater is a complex and costly process. With rising energy costs sustainability targets, treatment plants (WWTPs) are looking for alternatives to reduce operating carbon dependence. Anaerobic digestion the most common established technology used in WWTPs treat sludge since it can potentially improve recovery sewage costs, mainly due generation of biogas. Biogas renewable resource be several applications, including heating producing electricity. By exploring biogas potential, their demands. The objective this paper conduct scoping literature review order provide key concepts underpinning production utilisation WWTPs. In addition, study aims an overview current state-of-the-art that may serve as quick reference research community, WWTP operators, engineers, definitions general state technologies around world. Methods increase production, co-digestion, pre-treatment, biological hydrogen methanation, reviewed, using also summarised. This has identified co-digestion was efficient technique methane yield, while pre-treatment improved biodegradability reduced but enhanced production. Although many studies have explored different methods WWTPs, there still need further investigation, especially regarding techno-economic feasibility these full-scale facilities. challenges related extra investment increased integrate new techniques into system. There great interest efficiency self-sufficiency work provides important increasing number recently published papers focus on improving from