This review explores the potential of wastewater as a substrate for the production of clean, renewable energy in the form of hydrogen. The rich organic composition of wastewater pollutants provides an ideal medium for microbial biotransformation processes, enabling the conversion of these compounds into biohydrogen. Among others, emphasis is placed on the metabolic diversity of microorganisms, whose unique capabilities drive efficient hydrogen production. The review highlights advancements in microbial engineering for biohydrogen production, the role of diverse wastewater types, and the integration of hydrogen production with wastewater treatment as a sustainable energy recovery strategy.
Recent advancements include using genetically engineered microbes to enhance hydrogen yield, optimizing reactor designs for scaling up production, and integrating microbial consortia to improve efficiency. Studies demonstrate significant hydrogen yields from wastewater, including municipal, industrial, and agricultural effluents, often accompanied by simultaneous pollutant removal. Furthermore, incorporating nanoparticles yields higher hydrogen production.
This review examines the three primary mechanisms for biohydrogen production—photofermentation, dark fermentation, and biophotolysis—and the advances in developing genetically modified microorganisms to enhance hydrogen yields. It underscores microorganisms’ versatility in utilizing wastewater as a substrate for hydrogen production, showcasing their ability to efficiently transform organic pollutants into renewable energy. These advancements highlight integrating biohydrogen production with wastewater treatment as a sustainable solution to energy and environmental challenges.