ESTUDOS DE ADSORÇÃO DO CORANTE REATIVO AMARELO OURO EMPREGANDO CARVÃO ATIVADO DE CAROÇO DE PÊSSEGO COMO ADSORVENTE

Abstract

This work aimed at employing activated charcoal of peach kernel in the adsorption of the “Golden Yellow” reactive dye, since the raw material of the adsorber is a residue that is not very well explored for stain removal. The characterization of the physical and chemical properties of the activated charcoal was performed through the analyses of infrared spectroscopy, scanning electron microscopy (SEM), fisistion isotherms of N2, zeta potential, X-rays diffraction, iodine index, ashes content, and through the Boehm titration method. An adsorption study was carried out through the application of a 24 factorial design in order to assess the influence of the temperature, ion strength, adsorber mass and pH variables, and also to establish the optimun conditions for the adsorption of the golden yellow reactive dye: temperature = 25 °C, ion strength = 0,01 mol L-1 of KCl, adsorbent mass = 0,05 g and pH = 2,0 with agitation of 150 rpm. In this work, the training and validation of an algorithm of machine learning were also performed, called artificial neural network; the correlation obtained was 99,17% for the training and 99,82% for the validation of the method, with compatible results with the applied factorial design. By using the conditions of maximum adsorption, a kinetic study was carried out at different temperatures (25 °C, 35 °C, 45 °C and 55 °C), with adsorption balance achieved in 6 hours of contact for all the temperatures. A study of adsorption balance was also performed, where the Langmuir and Freundlich isotherms models were applied, being the first model the one that best related the experimental data, with maximum amount of dye adsorbed of 585,13 mg g-1 for a temperature of 45 °C. The thermodynamic parameters studied allowed the obtainment of enthalpy and entropy values of adsorption of 34,39 kJ mol-1 and 0,9450 J K-1 mol-1 respectively, besides an activation energy of -266,26 kJ mol-1 . In the face of the results obtained in the study, it can be concluded that the activated charcoal of peach kernel presented a good performance in the adsorption of the Golden Yellow reactive, having a potential for the removal of contaminants of textile effluents.