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Applied and Environmental Soil Science
Volume 2014 (2014), Article ID 369037, 8 pages
http://dx.doi.org/10.1155/2014/369037
Research Article

Clay and Soil Photolysis of the Pesticides Mesotrione and Metsulfuron Methyl

1Institut de Chimie de Clermont-Ferrand, Clermont Université and Université Blaise Pascal, Equipe Photochimie, BP 80026, 63171 Clermont Ferrand, France
2Clermont Université, ENSCCF, BP 10448, 63171 Clermont Ferrand, France
3Laboratoire GTVD, Faculté des Sciences, Université de Lomé, 05 BP 796, Lomé, Togo

Received 31 July 2013; Revised 21 November 2013; Accepted 5 December 2013; Published 29 January 2014

Academic Editor: Teodoro Miano

Copyright © 2014 Marie Siampiringue et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Photolysis may represent an important degradation process of pollutants at the surface of soil. In the present work, we report a detailed study on the degradation of two pesticides: mesotrione and metsulfuron methyl using a sunlight simulator. In a first step, we studied the photochemical behaviour at the surface of clays from the kinetic as well as from the analytical point of view. In both cases, the quantum yields were found to be higher when compared to those obtained in aqueous solutions. The effect of iron(III), water, and humic substances contents was studied. In the former cases, an increase of the degradation rate was observed while an inhibition was observed with the latter owing to a filter effect phenomenon. In a second step, we studied the photodegradation at the surface of natural soil and identified the generated byproducts. They appear to mainly arise from photohydrolysis process.