Oxidation of cosmetic wastewaters with H₂O₂ using a Fe/γ-Al₂O₃ catalyst

A catalyst based on Fe supported on γ-Al₂O₃ has been prepared and tested for catalytic wet peroxide oxidation (CWPO) of cosmetic wastewaters. The influence of the main operating conditions (space-time, temperature, and H₂O₂ dose) have been investigated. Working with this self-made Fe/γ-Al₂O₃ catalyst at 85°C, with a space-time of 9.4 kg_cat h/kg_COD and a dose of H₂O₂, corresponding to 0.5 times the theoretical stoichiometric H₂O₂/COD ratio, a substantial COD reduction (around 80%) has been reached with a complete consumption of H₂O₂. The locally allowable limit of COD for industrial wastewaters discharge to the municipal sewer system can be achieved at lower temperature and space-time. The catalyst showed a high stability in 100 h time on stream tests, where COD and TOC reductions around 82 and 60%, respectively, were maintained working at 85°C and 9.4 kg_cat h/kg_COD space-time. Fe leaching from the catalyst upon that time on stream was lower than 3% of the initial load.