Impregnação de carvão ativado com ferrita magnética para a aplicação na remoção de ácido salicílico em meio aquoso

Abstract

The large-scale use of emerging contaminants such as pharmaceuticals and personal care products (PPCP'S) has been raising concerns about environmental consumption. Within these PPCP'S is salicylic acid (SA) commonly used in cosmetic formulations. The PPCP'S are found in concentrations that vary from L-1 to μg L-1 in treated and wastewater, thus arising the need for new effective methods for the treatment of these contaminated waters. From this, this work aimed to evaluate the effectiveness of the removal of salicylic acid in aqueous medium, using a magnetic composite of activated carbon (AC) impregnated with cobalt ferrite (CoFe2O4) as adsorbent. This potential adsorbent and the cobalt ferrite were synthesized from the coprecipitation method, which were characterized together with the AC, by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) in order to compare and verify the impregnation efficiency. In addition to the zero load point (ZCP) experience. The adsorption capacity of the magnetic composite (CoFe2O4) was evaluated based on removal kinetics, isotherm and thermodynamic parameters, in which the adsorption tests were performed with variations in temperature, time and salicylic acid concentration. The micrographs are displayed as CoFe2O4 nanoparticles distributed on the AC surface. From the spectra it was possible to compare the AC bands before and after impregnation, which showed as bands referring to CoFe2O4 in the magnetic composite. XRD showed the presence of characteristic peaks of CoFe2O4 present in the magnetic composite (CoFe2O4/AC). The adsorption tests created a fast removal and that the impregnation did not affect the efficiency of the AC in the removal of the SA. A removal of 99.42% was achieved. From the kinetic parameters it was possible to observe that the model that best exhibits the adsorption of SA in the CoFe2O4/AC composite is the pseudo-second order model and demonstrated an isotherm modeled for Freundlich. Its thermodynamics followed an organized, spontaneous and endothermic pattern of ΔH= 33.3 kJ mol-1. The CoFe2O4/AC composite demonstrated adsorption with chemisorption and physisorption characteristics. The results obtained experimentally show that the composite CoFe2O4/AC is a good adsorbent for the removal of SA, and the adsorbent is easy to remove, which improves the application on large scales.