Green hydrogen from wastewater─a dual crisis resolution

Abstract

With continuous depletion of fossil fuels, a hike in global temperature due to CO₂ emissions, and increasing population of Earth, the demand for alternative green renewable energy sources has become undeniable. Hydrogen, a potential fuel for energy production, can be produced in a green way by water electrolysis with little to no carbon emissions. As some parts of the world still face the challenge of a drinking water crisis, using clean, drinkable water for hydrogen production becomes a concern. Households, agriculture, pharmacies, and industries release a lot of polluted wastewater into the environment, increasing biological oxygen demand and causing ecological imbalance. If wastewater is used as a feedstock for producing hydrogen, it can address both the energy crisis and water scarcity. In this review, hydrogen production from wastewater is classified into two parts: direct production and wastewater treatment methods followed by hydrogen generation. The technology, beyond all doubt, can be beneficial for green hydrogen generation, reducing carbon emission and contributing to a net-zero future.