Electrochemical treatment of industrial wastewater for hydrogen production

Over the past decade, one of the main challenges in the industry concerns reusing/recycling wastewater, mainly due to its high treatment cost and complexity. The integration of waste-to-hydrogen strategy proposes a potential revalorization of waste into value-added products towards a circular economy model. Integrating industrial wastewater (IWW) electrolysis into the supply chain potentially represents a sustainable approach for H2 production and wastewater treatment. This critical review analyses the current status and evaluates the main variables of a hydrogen production model using diverse IWW typologies in contrast to electrolytic water splitting and electrolysis of conventional organic compounds. Considering future prospects, further studies are highly required to assess the optimal configuration for each IWW with a well-balanced cost-sustainability-efficiency performance. •The valorization of wastewater-to-H2 fosters the transition to a circular economy.•Electrolysis of industrial wastewater (IWW) occurs at lower potential than water.•Electrochemical treatment of IWW reduces the pollution in water sources.•Ni electrodes are the optimal choice for black liquor (BL) electrolysers.•Hydrogen production from BL electrolysis slightly surpasses that of textile dyeing.