Study of herbicide ametryne degradation in HDPE packaging using the advanced oxidation process by ionizing radiation

This study is part of the project with the objective to evaluate pesticides degradation for decontamination of commercial polymeric packaging of high density polyethylene, HDPE, used in agriculture. The herbicide used to this study was the herbicide ametryne (commercial name, Gesapax 500), due to its great use, mainly on field crops and on corn. Ametryne is commercialized since 1975, and, depending on the pesticide formulation and type of application, residues may be detectable in water, soil and on the surfaces for months or years. In order to evaluate the efficiency of radiation processing on removal the pesticides contamination, HDPE packaging were irradiated using Radiation Dynamics Electron Beam Accelerator with 1,5 MeV energy and 37 kW, in batch system. The samples were irradiated with water, in various absorbed doses. Ametryne was analyzed by gas chromatography (GC Shimadzu 17A), after extraction with hexane/dichloromethane (1:1 v/v) solution. The calibration curve was obtained with a regression coefficient of 0.986, and the relative standard deviation was lower than 10%. The radiation processing yield was evaluated by the rate of ametryne degradation and by the destruction G-value (Gd). The electron beam irradiation processing, showed high efficiency in destroying ametryne in the HDPE packaging when the samples were irradiated in presence of small quantities of water. (author)