The performance of Fe-MnO2/CeO2, K-MnO2/CeO2/ Palygorskite and Fe/ Palygorskite catalysts during the wet oxidative degradation of phenol in a stirred reactor has been evaluated. The experiments were run at 130°C, 20.4 atm., and with an initial phenol and catalyst mass concentration of 0.5 g/L and 5 g/L, respectively. The influence of iron loaded on the support (0, 3; 7 and 10%, m/m) and the initial pH of the reactant medium (3.1; 6.8; 8.7) were studied. The phenol degradation curves showed that the Fe+2//Palygorskite catalyst had the best performance toward the organic carbon conversion compared to the other catalysts. It was also found that by lowering the alkalinity of the reacting media favoured the phenol conversion and that the Palygorskite support showed higher resistance to the actions of the acids formed during the reaction.

Se ha evaluado el funcionamiento de catalizadores Fe-MnO2/CeO2, K-MnO2/CeO2/Paligorsquita y Fe/Paligorsquita en la degradación oxidativa húmeda del fenol en un reactor de mezcla. Los experimentos se ejecutaron a: temperatura de 130º C, presión de 20.4 atm., concentración másica del catalizador de 5 g/L y concentración inicial del fenol de 0,5 g/L Los parámetros evaluados fueron: contenido de hierro impregnado (0, 3; 7 y 10%, m/m) y el pH inicial del medio reactivo (3.1; 6.8 y 8.7). Las curvas de degradación del fenol indican que el catalizador Fe+2/Paligorsquita tiene un papel preponderante en la conversión de carbono orgánico total comparado con los demás catalizadores. Se encontró también que la disminución de la alcalinidad del medio reactivo favorece la conversión de fenol y que el soporte paligorsquita parece ser más resistente a la acción de los compuestos ácidos formados durante la reacción.

In the present work, a synthetic effluent of phenol was treated by means of a total oxidation process-Catalyzed Wet Oxidation (CWO). A mixed oxide of Mn-Ce (7:3), the catalyst, was synthesized by co-precipitation from an aqueous solution of MnCl2 and CeCl3 in a basic medium. The mixed oxide, MnO2/CeO2, was characterized and used in the oxidation of phenol in a slurry reactor in the temperature range of 80-130ºC and pressure of 2.04-4.76 MPa. A phenol solution containing 2.4-dichlorophenol and 2.4-dichlorophenoxyacetic acid was also degraded with good results. A lumped kinetic model, with two parallel reaction steps, fits precisely with the integrated equation and the experimental data. The kinetic parameters obtained are in agreement with the Arrhenius equation. The activation energies were determined to be 38.4 for the total oxidation and 53.4 kJ/mol for the organic acids formed.