Different degradation methods have been applied to assess the suitability of advanced oxidation process (AOPs) to promote mineralization of imazethapyr, (RS)-5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid, a widely used imidazolinone class herbicide, the persistence of which has been demonstrated in surface and ground waters destined to human uses. Independently of the oxidation process assessed, the decomposition of imazethapyr always followed a pseudo-first order kinetic. The direct UV-irradiation of the herbicide as its oxidation with O3 and H2O2/UV-oxidation were sufficiently slow to permit the identification of intermediate products, the formation pathway of which has been proposed. O3/UV, O3/UV+TiO2, TiO2/UV, and TiO2/UV+H2O2 treatments were characterized by a faster degradation and rapid formation of a lot of little molecules, which were quickly destroyed.
NEW ASSESSMENT OF DEGRADATION METHODS FOR MICROPOLLUTTANTS:SEVERAL ALTERNATIVES FOR IMAZETHAPYR DETOXIFICATION
SCRANO, Laura;LELARIO, FILOMENA;BUFO, Sabino Aurelio
2006-01-01
Abstract
Different degradation methods have been applied to assess the suitability of advanced oxidation process (AOPs) to promote mineralization of imazethapyr, (RS)-5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid, a widely used imidazolinone class herbicide, the persistence of which has been demonstrated in surface and ground waters destined to human uses. Independently of the oxidation process assessed, the decomposition of imazethapyr always followed a pseudo-first order kinetic. The direct UV-irradiation of the herbicide as its oxidation with O3 and H2O2/UV-oxidation were sufficiently slow to permit the identification of intermediate products, the formation pathway of which has been proposed. O3/UV, O3/UV+TiO2, TiO2/UV, and TiO2/UV+H2O2 treatments were characterized by a faster degradation and rapid formation of a lot of little molecules, which were quickly destroyed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
