Satishkumar, P.Isloor, A.M.Farnood, R.2026-02-082023Materials for Hydrogen Production, Conversion, and Storage, 2023, Vol., , p. 277-31897811198293489781119829584https://doi.org/10.1007/s12046-025-02990-whttps://idr.nitk.ac.in/handle/123456789/33639Biohydrogen production from wastewater is a prominent way to address escalating global energy demand and alarming environmental pollution. The need for renewable, sustainable, economic, and environment-friendly pathways for energy generation is fulfilled by biohydrogen evolution. Wastewaters contain a vast array of organic contents, as well as microbes and are a suitable source for bioreactors. Treatment of wastewaters with hydrogen-generating bacteria significantly aids its purification process by reducing chemical oxygen demand with simultaneous hydrogen generation. Among the various methods that are available for hydrogen production from microbes, photo fermentation, dark fermentation, and microbial electrolysis cells are discussed thoroughly. Continuous hydrogen generation systems are most suitable for large scale commercial production. Uniform product quality is obtained in the case of continuous systems. Microbial electrolysis cells have been found to yield exceptionally good hydrogen purity. A variety of factors that affect hydrogen evolution in all the techniques are reviewed in detail. © 2023 Scrivener Publishing LLC. All rights reserved.BiohydrogenContinuous hydrogen productionDark fermentationMicrobial electrolysis cellPhoto fermentationWastewater treatment