Sorção, dessorção e lixiviação do sulfentrazone em diferentes solos brasileiros

• Autor(a) principal: Passos, Ana Beatriz Rocha de Jesus
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2107
• topic: Herbicida; Impacto ambiental; Solos; Herbicide; Environmental impact; Soils; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA

With this work was evaluated the processes of sorption, desorption and leaching of sulfentrazone in soils with different physical and chemical characteristics of the southern and southeastern Brazil. To study the sorption and desorption it was used the method "Batch Equilibrium" and analysis by high performance liquid chromatography with UV-Vis detector at 214 nm. Based on the results obtained from the values of Freundlich constants (Kf), it was determined that the sorption and desorption of sulfentrazone in soils obeys the following order: Sorption: Haplic Planosol < Red-Yellow Latosol Argisol < Red Argisol< Humic Cambisol < Entisol; Desorption: Entisol < Red Argisol < Humic Cambisol < Haplic Planosol < Red-Yellow Latosol. The mobility of sulfentrazone was evaluated in soil columns made of PVC pipes 10 cm in diameter and 50 cm long, and filled with previously prepared samples of these soils. On top of these columns, containing the soil moisture close to field capacity was applied sulfentrazone, and 24 hours after a simulation was carried out 60 mm of rain for about 5 hours. After draining the water columns were opened and taken soil samples from each segment of 5.0 cm (0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35 , 35-40, 40-45 and 45-50 cm) for analysis of sulfentrazone by high performance liquid chromatography. The active principle was extracted from soil by the extraction technique with solid-liquid partition at low temperature (ESL-PBT) which was adapted and validated. The sulfentrazone has high mobility in the four soils studied, being smaller than the Humic Cambisol due to its lower percentage of desorption. In this soil, the herbicide remained in the upper layers of the column while the remaining distribution of the herbicide occurred along these. But the soil that retained the highest concentration of the compound in the first column was the depths of the Red Argisol, which had the highest content of clay. It was concluded that the processes of sorption, desorption and leaching of sulfentrazone in soils are dependent on the assessed chemical and physical characteristics of these, and the main content of clay and sand and organic matter.