Adsorção de tetraciclina em carvão ativado obtido do caroço do açaí (Euterpe oleracea M.)

Abstract

Emerging contaminants include pharmaceuticals and, in this category, antibiotics, which are substances exclusively used and prescribed to treat infections in humans and other animals. Antibiotics are not completely metabolized by the body and are partially eliminated in feces and urine that are part of sewage treatment systems along with hospital and pharmaceutical industry effluents. Recent research shows that antibiotics appear in water and treated sewage in practically unchanged concentrations when compared to input concentrations, reducing the fact that conventional systems are not efficient in removing the substances produced. Although there is no regulation for the limits produced in the environment, the challenge for science is to study possible removal methods. In this study, the adsorption of the antibiotic tetracycline was evaluated using carbons activated by H3PO4 and KOH obtained from the açaí seed (Euterpe oleracea M.) which were carbonized at different temperatures. For statistical analysis, the mixed design (3¹ x 2²) was applied, which shows that activation with KOH and pH 3.0 of the tetracycline solution are variables that favor the adsorption of the antibiotic. The material obtained was characterized by Fourier transform infrared spectroscopy. Adsorption kinetics and equilibrium studies showed that the pseudo-second order and Freundlich models, respectively, described an adsorbate-adsorbent interaction with the best fit to the data.