Catalysis Today, Vol.151, No.1-2, 148-152, 2010
Catalytic wet peroxide oxidation of cosmetic wastewaters with Fe-bearing catalysts
Catalysts based on Fe supported on gamma-Al(2)O(3) and active carbon (AC) have been prepared and tested for catalytic wet peroxide oxidation (CWPO) of cosmetic wastewaters. The catalysts were characterized by TXRF, XPS, XRD, SEM, elemental chemical analysis, Mossbauer spectroscopy and 77 K N(2) adsorption-desorption. The catalytic performance was monitored in terms of COD, TOC and H(2)O(2) conversions. The possible leaching of iron from the catalyst was also checked. The influence of the catalysts preparation conditions (calcination temperature and Fe content) as well as the operating temperature in the oxidation process has been studied with the purpose of optimization. Working at 85 degrees C with a Fe/gamma-Al(2)O(3) catalyst calcined at 300 degrees C and with 4% Fe content, a remarkable COD reduction (around 85%) has been reached. However, lower temperatures are sufficient to fulfill the locally allowable limit of COD for industrial wastewaters discharge into the municipal sewer system. A substantial improvement of biodegradability (BOD(5)/COD ratio) was observed. Thus, CWPO could be effectively applied whether as a treatment itself or as a pre-treatment addressed to improve subsequent biodegradability of these wastewaters. The Fe/gamma-Al(2)O(3) catalyst showed a reasonable stability, a relatively low decrease of activity (15%) being observed after three successive runs. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
Keywords:AOPs;Catalytic wet peroxide oxidation;Cosmetic wastewaters;Alumina and active carbon-supported iron catalysts;Heterogeneous Fenton process;Hydrogen peroxide