Síntese de materiais adsorventes à base de quitosana, escamas de peixe e amido de milho – aplicação em remoção de fármacos em meios aquosos

Abstract

The contamination of water by pharmaceuticals is an emerging concern, because some drugs remain resistant even after water treatments. Among several removal processes of this type of pollutant, sorption from solution using adsorbent materials has been considered one of the most effective. In this study, we aimed to develop new adsorbent materials based on chitosan (QT) and corn starch (AMD), both modified with hydroxyapatite (HA) powder extracted from fish scales. The sorption kinetics of the drugs ciprofloxacin (CPX) and acyclovir (ACV) were studied at temperatures of 25, 35 and 45 ° C in buffered solutions (pH 2-5). For the chitosan-based materials (QTHA 1, QTHA 2 and QTHA 3), drugs sorption were fast, observing 45 min up to sorption equilibrium, while sorption times of CPX and ACV in the starch-hydroxyapatite material (AMDHA) were slightly higher (about 60 min). The sorption behavior of the drugs in both type of materials followed the kinetic models of pseudo-second order and the variable kinetic constants. The Morris-Weber model suggests that intraparticle diffusion was not the main sorption rate step, but external boundary layer diffusion processes also affect the sorption of the drugs. It is proposed that the increasing of temperature has reduced the external boundary layer and increases the diffusion rates of the drugs. The prepared materials were proved to be promising for the sorption of drugs in aqueous media.