The photodegradation of two quinolinecarboxylic herbicides, 7-chloro-3-methylquinoline-8-carboxylic acid (QMe) and 3,7-dichloroquinoline-8-carboxylic acid (QCl), was studied in aqueous solution at different irradiation wavelengths. The effect of sunlight irradiation was investigated also in the presence of titanium dioxide (TiO2). UV irradiation degraded rapidly QMe affording 7-chloro-3-methylquinoline (MeQ) through a decarboxylation reaction. The reaction rate was lower in the presence of dissolved organic carbon (DOC) because of the adsorption of the herbicide on the organic components. Instead, QCl was stable under both UV light and sunlight irradiation. The irradiation of QMe or QCl solutions with simulated sunlight in the presence of TiO2 produced the complete mineralization of the two herbicides.
Direct and indirect photolysis of two quinolinecarboxylic herbicides in aqueous systems / Pinna, Maria Vittoria; Pusino, Alba. - In: CHEMOSPHERE. - ISSN 0045-6535. - 86:(2012), pp. 655-658. [doi:10.1016/j.chemosphere.2011.11.016]
Direct and indirect photolysis of two quinolinecarboxylic herbicides in aqueous systems
Maria Vittoria Pinna;PUSINO, Alba
2012-01-01
Abstract
The photodegradation of two quinolinecarboxylic herbicides, 7-chloro-3-methylquinoline-8-carboxylic acid (QMe) and 3,7-dichloroquinoline-8-carboxylic acid (QCl), was studied in aqueous solution at different irradiation wavelengths. The effect of sunlight irradiation was investigated also in the presence of titanium dioxide (TiO2). UV irradiation degraded rapidly QMe affording 7-chloro-3-methylquinoline (MeQ) through a decarboxylation reaction. The reaction rate was lower in the presence of dissolved organic carbon (DOC) because of the adsorption of the herbicide on the organic components. Instead, QCl was stable under both UV light and sunlight irradiation. The irradiation of QMe or QCl solutions with simulated sunlight in the presence of TiO2 produced the complete mineralization of the two herbicides.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
