Sunlight nitrate-induced photodegradation of chlorotoluron: evidence of the process in aquatic mesocosms.
The nitrate-induced photodegradation of chlorotoluron was demonstrated to occur efficiently in natural water through two series of experiments in outdoor aquatic mesocosms. During the first campaign, it was shown that the pesticide degradation kinetics was clearly dependent on nitrate concentration. This parameter also influenced the accumulation of the first- and second-generation byproducts, including predominantly N-terminus oxidation products and nitro-derivatives of the phenyl ring. The latter compounds, specific to the NO3- -induced photoprocess, appeared particularly abundant as compared to laboratory-simulated sunlight irradiation conditions. During the second campaign, a dual day-night sampling was achieved, which demonstrated the almost exclusive role of photodegradation versus biodegradation.
Nélieu
Sylvie
S
INRA, UR 258 Phytopharmacie et Médiateurs Chimiques, 78000 Versailles, France. nelieu@versailles.inra.fr
Perreau
François
F
Bonnemoy
Fréderique
F
Ollitrault
Martine
M
Azam
Didier
D
Lagadic
Laurent
L
Bohatier
Jacques
J
Einhorn
Jacques
J
D019015:Geologic Sediments / Q000737:chemistry; D009566:Nitrates / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry; D010671:Phenylurea Compounds / Q000737:chemistry* / Q000528:radiation effects*; D010782:Photolysis / Q000528:radiation effects*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013472:Sunlight; D014867:Water / Q000737:chemistry*
D009566:Nitrates; D009573:Nitrites; D010671:Phenylurea Compounds; D000644:Quaternary Ammonium Compounds; D014867:Water; C007033:chlortoluron