Thermophilic Dark Fermentation of Olive Mill Wastewater in Batch Reactors: Effect of pH and Organic Loading

In recent decades, olive oil consumption has almost tripled worldwide. Olive production is linked with the of enormous amounts mill wastewater, main by-product derived from three-phase mills. Due to environmental risks wastewater disposal, management and valorization specific waste stream great importance. This work focuses on thermophilic dark fermentation in batch reactors, targeting pH optimization organic loading effect. A series experiments were performed, during which load substrate remained at 40 g/L after dilution tap water, was tested range 4.5 7.5. The maximum yield terms produced hydrogen obtained 6.0, yields 0.7 mol H2/mol glucose or 0.5 L H2/Lreactor. At same conditions, a reduction 62% waste’s phenols achieved. However, concerning effect optimized value (6.0), further increase minimized production, overall process strongly inhibited.