COD and AOX abatement in catalytic wet oxidation of halogenated liquid wastes using CeO2-based catalysts

The treatment of halogenated containing compounds is one of the more promising applications of catalytic wet oxidation (CWO) reaction. The aim of this work is to compare the abatement of chemical oxygen demand (COD) and adsorbable organic halogen (AOX) parameters in three halogenated liquid wastes: a landfill leachate, a pulp and paper bleaching liquor and a heavily organic halogen polluted industrial wastewater, treated at 430-500 K in a batch bench-top pressure vessel. Two catalysts based on ceria were used: a pure CeO2 and a SiO2-doped ceria characterized by different surface area and oxygen storage capacity. The efficiency of the catalytic process was examined controlling COD and AOX parameters; the catalysts deactivation was observed by the measurement of the surface area and the increase of the carbon content of the catalysts after the reactions. (c) 2005 Elsevier B.V. All rights reserved.