Catalytic ozonation of fenofibric acid over alumina-supported manganese oxide.

The catalytic ozonation of fenofibric acid was studied using activated alumina and alumina-supported manganese oxide in a semicontinuous reactor. The rate constants at 20°C for the non-catalytic reaction of fenofibric acid with ozone and hydroxyl radicals were 3.43±0.20M−1s−1 and (6.55±0.33)×109M−1s−1, respectively. The kinetic constant for the catalytic reaction between fenofibric acid and hydroxyl radicals did not differ significantly from that of homogeneous ozonation, either using Al2O3 or MnOx/Al2O3. The results showed a considerable increase in the generation of hydroxyl radicals due to the use of catalysts even in the case of catalytic runs performed using a real wastewater matrix. Both catalysts promoted the decomposition of ozone in homogeneous phase, but the higher production of hydroxyl radicals corresponded to the catalyst with more activity in terms of ozone decomposition. We did not find evidence of the catalysts having any effect on rate constants, which suggests that the reaction may not involve the adsorption of organics on catalyst surface.