Utilização de carvão ativado para tratamento de efluentes gerados em planta de formulação de defensivos contendo acefato

Abstract

The production of agricultural pesticides generates effluents from the formulation process that must be disposed of correctly in accordance with current regulations in each country. In Brazil, there are some parameters that must be met so that these effluents can be disposed of in receiving bodies. Acephate is the 5th best-selling active ingredient in tons in Brazil, and due to this large volume, it is the object of this study. Activated carbon is known as an adsorbent with great capacity for filtration and purification of mixtures and based on this knowledge, this work aims to verify the possibility of using it to achieve these parameters. The research was carried out using the liquid chromatography technique to quantify the effluent containing acephate in contact with activated carbon. Using Langmuir, Freundlich, Sips, Toth, Redlich Peterson and Jovanovich isotherms, it was evaluated through linear and non-linear adjustments, which model was best adapted to represent the acephate adsorption process on activated carbon. The Freundlich isotherm model stood out when compared to all other models in both linear and nonlinear adjustment. It was also possible to verify through the nonlinear constants that the process obtained a better performance at temperatures of 30°C and 35°C, however, the adsorption process proved to be unfavorable, showing that activated carbon used is not the best choice for acephate adsorbent in aqueous phases.