Adsorção de eteramina em caulinita natural e tratada com H2O2: proposição de alternativas para o tratamento de efluentes de mineração

Abstract

The work consisted of comparing the adsorption of etheramine, reagent used in the flotation of iron ore, on natural kaolinite (CN) and kaolinite modified with peroxide (CP). The Response Surface methodology was applied in order to optimize the process and assess the influence among the parameters. The adsorption was more efficient in the concentration of etheramine of 400 mg L-1, pH 10 and adsorbent mass of 0.1 g for CN, while for CP the optimum adsorbent mass was 0.2 g. The treatment did not result in a significant improvement of adsorption efficiency. By means of the kinetics of 24 h it was possible to observe that equilibrium was achieved in approximately 30 min. The kinetic data had a better adjust to the kinetic model of pseudo-second order. The isotherm data were better adjusted to the Sips model and Eads values indicate that the process involves a chemisorption. The adsorption in kaolinite may be a feasible alternative for the treatment of mining effluents, with the natural kaolinite standing outs the treatment did not result in any significant improvement.