Pollution abatement techniques, inexpensive and environmentally friendly, are highly desirable and recommended. That is a reason when heterogeneous photocatalysis using TiO2 as a semiconductor is of considerable interest. In this study, the performance of 5 materials was evaluated in the photocatalytic degradation of diuron herbicide. The kinetic of disappearance is pseudo-order 1 whatever the material. This photodegradation is very little influenced by the initial pH of the solution; even if the best results are obtained for initial pH between 5 and 8. The presence of ions such as nitrate, sulfate and ammonium ions in the reaction medium causes a slight decrease in the initial rate of disappearance of the pollutant. This is explained by a competitive adsorption between the pollutant and the added ions and / or an oxidation reaction of these ions by the photogenerated oxidative species. A photocatalytic degradation order of the diuron according to the material used has been established. This order would be: TiO2 P25 > TiO2 PC500 > Our TiO2 > Quartzel > Média 1048.
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