DEGRADATION OF HERBICIDE ATRAZINE IN WATER BY FENTON AND FOTO-FENTON PROCESSES

BENZAQUÉN, TAMARA B.;CURCIO, ALFANO, ORLANDO M.; INÉS; ISLA, MIGUEL A.

Rio de Janeiro

Congreso; VI Encontro sobre Aplicações Ambientais de Processos Oxidativos Avançados; 2011

Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a member of s-triazine group of herbicides. It is one of the most widely used pesticides in the World, mainly for pre and post emergence control of annual grass and broad-leafed weeds in corn cultures. Because of its persistence and its extended and prolonged use, traces of triazine herbicides have been found in water bodies. It is known that these pesticides have endocrine disrupting capabilities, being classified as a possible human carcinogen by the US EPA. Atrazine was included in the Water Framework Directive list of priority hazardous substances; therefore it has been banned in some countries. Previous work showed that Atrazine has a negative impact on the activity of microorganisms present in a biological treatment system [1]. Fenton and photo-Fenton reactions are known for their capacities for the oxidation and even complete mineralization of a great variety of non biodegradable compounds. These capacities mainly depends on radiation and hydrogen peroxide and iron concentrations. In this work, optimization of reagent concentrations was performed to achieve the degradation of the herbicide. Degradability assays were carried out in a lab-scale photochemical reactor operated in batch mode, with ferric salt and hydrogen peroxide initial concentrations falling in the ranges 5 - 15 ppm and 0.5 - 5 mM respectively, in dark and irradiated conditions.