Solar photodegradation of pesticides in water by sodium decatungstate

I. Texier; C. Giannotti; S. Malato; C. Richter; J. Delaire

doi:doi:10.1051/jp4:1999344

Issue		J. Phys. IV France Volume 09, Number PR3, March 1999 Proceedings of the 9^th SolarPACES International Symposium on Solar Thermal Concentrating Technologies STCT 9


Page(s)		Pr3-289 - Pr3-294
DOI		https://doi.org/10.1051/jp4:1999344

Proceedings of the 9^th SolarPACES International Symposium on Solar Thermal Concentrating Technologies
STCT 9

J. Phys. IV France 09 (1999) Pr3-289-Pr3-294
DOI: 10.1051/jp4:1999344

Solar photodegradation of pesticides in water by sodium decatungstate

I. Texier^{1, 2}, C. Giannotti¹, S. Malato³, C. Richter³ and J. Delaire²

¹ Institut de Chimie des Substances Naturelles, avenue de la Terrasse, 91198 Gif-sur-Yvette, France
² PPSM, URA 1906, 61 avenue du Président Wilson, 94235 Cachan cedex, France
³ Plataforma Solar de Almeria, P.O. Box 22, 04200 Tabernas, Almeria, Spain

Abstract
Solar photodecomposition of aqueous solutions of phenol, 4-chlorophenol, 2,4-dichlorophenol, bromoxynil, atrazine, imidachloprid and oxamyl in the presence of two photocatalysts titanium dioxide TiO₂ and sodium decatungstate Na₄W₁₀O₃₂ is reported. Titanium dioxide appears to be the most efficient photocatalyst concerning the rate of photodegradation and mineralisation of the pure compounds. However, when the pesticides are used in formulated solutions, the decatungstate anion becomes as efficient or even more efficient than TiO₂. The mechanisms of the photodegradation in the presence of the two photocatalysts are discussed. They appear to be different, accounting for the observed difference of reactivity.