Estudo da cinética e equilíbrio de adsorção de corante reativo sobre carvão ativado magnético

Abstract

One of the biggest challenges of the textile industry is the removal of the dye present in its effluents. In order to improve existing treatments, the search for new technologies that present low cost, efficiency and that do not harm the environment becomes necessary. The present work aimed to study the kinetics and adsorption balance of reactive black dye 5 (RB5) on magnetic activated carbon (FeBC) temperatures of 25° and 32°C in batch ing system. The kinetic parameters were obtained by the pseudo-first and pseudo-second order models in which the pseudo-second model adjusted better for both temperatures, presenting values of kinetic constants (k2) of 5.5 x 10-4 h-1 and 8.4 x 10-4 h-1 for temperatures of 25 and 32ºC, respectively. The adsorptive capacity of FeBC was evaluated using the Langmuir, Freundlich and BET isotherm models at temperatures of 25°, 32°C and 40°C. The model that best fit was BET, indicating that adsorption occurs in two mechanisms: formation of monolayer in lower concentration of dyes and multilayer for high concentrations. The results obtained were satisfactory for the use of FeBC as adsorbent for RB5 at different temperatures, presenting qmax values of 32.897 mg g-1, 43.681 mg g-1 and 58.008 mg g-1 for 25º, 32º and 40ºC, respectively. In addition, it becomes advantageous for the process, as it can be removed from the medium with the use of magnets.