The present chapter explores the mechanisms and processes involved in the anaerobic digestion (AD) of organic waste present in wastewater, which seldom leads to the production of biogas—a renewable energy source rich in methane. By laying emphasis on the dual benefits of waste reduction and energy generation, the study provides a comprehensive overview of the latest advancements in AD technologies. It discusses the integration of diverse technologies into existing wastewater treatment facilities, also highlighting the economic and environmental advantages of biogas production. As well, the study examines case studies where AD has been successfully implemented, and demonstrated its feasibility and scalability. Again, we discussed the optimization techniques essential for maximizing biogas yield, including temperature control, pH regulation, and co-digestion strategies with other organic wastes. The environmental impact of biogas production is also analyzed, highlighting the reduction in greenhouse gas emissions compared to conventional waste treatment methods. Artificial intelligence (AI) integration for process control and the use of genetically engineered microorganisms to enhance efficiency are novel/smart technologies reviewed. Ample knowledge of scalability of bioenergy recovery from wastewater will trigger its recommendations for improvements to encourage broader implementation.