Síntese de nanocompósito magnético: γ-Fe2O3/carvão ativado

Abstract

The present work refers to the preparation of a composite consisting of maghemite nanoparticles impregnated on the surface of an activated carbon matrix (γ-Fe2O3/CA), from the co-precipitation of Fe3+ and Fe2+ metallic cations in the presence of the matrix. This material has an important application in the area of environmental depollution, and can be used in the rapid and selective adsorption of contaminants contained in wastewater, and later isolated by magnetization. The γ-Fe2O3/CA composite was used in adsorption experiments of bright blue dye (AB) in a simulated aqueous solution of contaminated water (10 mg AB/L). In the experiments, the mass of composite used was varied and the supernatants isolated after the adsorption test were analyzed by spectroscopy in the UV-Vis region. From the absorbance values and Lambert-Beer law it was possible to calculate the adsorption efficiency (83 to 100%). The AB photodegradation procedure was performed on a γ-Fe2O3/CA sample, right after the composite was used in an adsorption test, in order to remove the adsorbed dye and evaluate the possibility of its reuse in new experiments of adsorption. However, an efficiency of only 73.3% was observed. In addition, the adsorption test with a raw maghemite sample showed that iron oxide partially contributes to the dye adsorption process (28.1%), with the CA matrix being the main material responsible for this work.