Photominéralisation de l'uracile et des 5-halogeno-uraciles sur le dioxyde de titane. Effet du pH et de quelques anions sur la photodégradation de l'uracile

Abstract

In oxygenated aqueous solutions, the photocatalytic degradation of uracil and its halogenated homologous is achieved on irradiated titanium dioxide. The kinetics of disappearance and mineralisation in carbon dioxide, ammonium, and nitrate ions are established. In presence of chloride, carbonate, sulphate and nitrate ions, photodisappearance of uracil is inhibited. This can be due to a partial blockage of catalyst active sites by these ions or their reaction with the oxidizing radicals such as HO3/0 or OH0. It is reported that, at pH lower than 6, disappearance kinetics of this pollutant is reduced.