Adsorção de agrotóxico por nanopartícula recuperada de atividade industrial em presença e ausência de matéria orgânica

Abstract

Due to the occurrence of rains, the leaching of pesticide molecules present in soils can be transferred to groundwater. Herbicides are a type of pesticide widely used in Brazil. The southwestern region of Paraná is among the most consuming pesticides, as it has a large area of agricultural production, such as maize planting, predominant in the region, thus requiring the application of the herbicide Atrazine (ATZ) on a large scale to avoid action of weeds. One technique that can be developed to reduce the drag of agrochemicals to groundwater is to promote the adsorption of herbicide through the action of nanoparticles. The use of iron nano-oxides such as the recovered goethite from mining waste may be an alternative. In this work, the resulting ATZ was quantified in rainwater (AC) leached in columns of fixed beds containing 120 g of soil sterilized in each. The beds were submitted to the experimental situations: percolation of the AC in natural soil; AC in soil with ATZ, AC in soil with humic acid (HA) content; of the AC in soil with nanoparticle (NP) and the AC in soil with AH and NP. The leached waters were collected in the 60 and 120 minute times after finishing the fixed bed. All experiments were done in triplicate. The ATZ content in the CA that passed through soils with increased organic matter (OM), by the addition of AH was lower than in NPonly situations. The lowest concentrations of ATZ in the leachate waters of the beds were found when humic acid and nanogoethite were used in a unified form, which contributed to the herbicide retention in the soil.