Hydrogen peroxide-promoted-CWAO of phenol with activated carbon

The effect of hydrogen peroxide as radical promoter in the wet air oxidation of phenol with activated carbon catalysts is studied in a trickle-bed reactor at 127 °C, 8 atm and 20–320 gAC h/gPhenol. The modifications that hydrogen peroxide induces on the radical reaction mechanism and the consequences on the effluent ecotoxicity are analyzed. The synergistic effect between oxygen and hydrogen peroxide in the initiation step of the reaction is verified. Hydroperoxy radicals, produced by the reaction between hydrogen peroxide and adsorbed oxygen, initiate the reaction on the carbon and in the liquid phase. They are responsible for the increased initial activity which provokes a faster removal of phenol and aromatic intermediates and, therefore, of the toxicity. The adsorbed oxygen on the carbon is crucial for the efficient consumption of hydrogen peroxide.