The rapid increase in human activity in recent years has increased energy demand and waste output. Although wastewater is frequently seen as a problem, it has the potential to be seen as a rich source of resources and energy. An appealing approach to lowering environmental pollution and supplying alternative energy sources is the treatment of contaminants found in wastewater combined with energy recovery. Microbial electrolysis cell (MEC) is one of the most effective waste-to-product conversion technologies available today. There are other methods for wastewater treatment and the production of hydrogen as dark fermentation and photo fermentation. This paper explores the interconnected fields of wastewater treatment and hydrogen production, highlighting their significance in addressing environmental challenges and promoting sustainable development. Various technologies and processes employed in wastewater treatment, such as microbial electrolysis cells (MECs), dark fermentation, and photo fermentation, are discussed in detail. Also, This paper compares MEC, photo fermentation, and dark fermentation for hydrogen production and wastewater treatment. Moreover, it shows some benefits and drawbacks of these technologies. In addition, the integration between these technologies is discussed in this review. Additionally, it provides some descriptive statistics about the outcomes. Finally, some recommendations are presented in the review for future work.