Adsorção de metribuzin em leito fixo de adsorvente derivado de casca de banana

Abstract

The increase in the production of pesticides is increasing over the years, a fact responsible for the constant increase in inhabitants, directly impacting the agricultural sector, which seeks techniques that tend to maximize the harvest. In order for this maximization to take place, pesticides are used to combat possible pests that may threaten or already threaten the yield of the harvest. With that, despite presenting an economic advantage for the farmer, one presents for the environment, directly impacting the soils, which suffer leaching and end up intoxicating groundwater and later rivers and lakes. In view of this, the present work presented the objective of carrying out the removal of the herbicide metribuzin through the adsorption method in a fixed bed, using biosorbent and biochar derived from banana peel, specifically from the silver species. To evaluate the effluent, a characterization was performed using the Fourier Transform Infrared Spectroscopy method, in order to evaluate the chemical groups that form the metribuzin molecule. To obtain the process variables, the mathematical models of Thomas, Yan and Yoon-Nelson were used through the Curve Fitter tool available in the MatLab software, thus obtaining the parameters of the models. For quantification of metribuzin, a calibration curve was performed so that it presented R2 = 0.9997. Regarding the adsorption process, the mathematical model of Yan best adapted to the experimental data of the biosorbent (R2 = 0.8866) and through it it was possible to obtain the adsorption capacity of the biosorbent, being 11.75 mg g-1. Regarding biochar, the models that best adapted to the experimental data were the Thomas and Yoon-Nelson model (R2 = 0.9677, for both), presenting identical adjustments, which, according to the literature, was already expected. The adsorption capacity of biochar, found through the models, was also the same for both models, being 13.84 mg g-1. Through the characterization by the FTIR method, it was possible to observe the presence of peaks representing the chemical compounds that form the metribuzin molecule, in addition to peaks that can be experienced as other substances present in the commercial product Sencor® 480. Therefore, the present work presents satisfactory results for biochar when compared to biosorbent, in addition to presenting promising results for removal of metribuzin through fixed bed using biosorbent and biochar derived from banana peel, which is a viable and economical source of raw material.