An Assessment of Agro-Industrial Wastewaters as a Resource for Biohydrogen Recovery Potential Using Dark Fermentation Biorefineries

South Africa’s agro-industrial sector generates substantial volumes of wastewater, presenting both environmental challenges and opportunities for renewable energy production, particularly through the development of biohydrogen. Valorising these waste streams aligns with national strategies promoting the circular economy, the Hydrogen Society Roadmap (DSI, 2021) and the Bioeconomy Strategy. This study assessed the agro- industrial sector's potential for biohydrogen production via dark fermentation, focusing on waste- stream quantification, spatial mapping, identification of high- potential streams, and technical feasibility. In this regard, a mixed- methods approach was applied, including literature review, industry surveys, geospatial analysis, and laboratory -scale experimental work. Data from various sources were used to estimate wastewater volumes, organic loads, and nutrient composition.