Kinetics of catalytic wet peroxide oxidation of phenolics in olive oil mill wastewaters over copper catalysts

During olive oil extraction, large amounts of phenolics are generated in the corresponding wastewaters (up to 10 g dm–3). This makes olive oil mill wastewater toxic and conventional biological treatment challenging. The catalytic wet peroxide oxidation process can reduce toxicity without significant energy consumption. Hydrogen peroxide oxidation of phenolics present in industrial wastewaters was studied in this work over copper catalysts focusing on understanding the impact of mass transfer and establishing the reaction kinetics. A range of physicochemical methods were used for catalyst characterization. The optimal reaction conditions were identified as 353 K and atmospheric pressure, giving complete conversion of total phenols and over 50% conversion of total organic carbon content. Influence of mass transfer on the observed reaction rate and kinetics was investigated, and parameters of the advanced kinetic model and activation energies for hydrogen peroxide decomposition and polyphenol oxidation were estimated.