Utilização de carvão ativado de dendê in natura e funcionalizado em meio ácido na adsorção de paracetamol

Abstract

A possible solution for the removal of pharmaceuticals in water bodies is by means of adsorption with activated carbon. The objective of this work was to study the utilization of dendê carbon in nature and functionalized with nitric acid (HNO3) in the paracetamol adsorption. The samples were characterized as the textural and chemical properties. Kinetic and equilibrium assays were performed with both samples at pH values: 2.0, pHPZC, 11.0 at 25 °C. Micropore blocking seemed to take place in the functionalized activated carbon by oxide groups introduced by the chemical treatment, thus causing decrease in the removal efficiency of paracetamol. In the Boehm method was observed an increase in the acid groups and a decrease in the pHPZC values. The kinetic model of pseudo-second order and the equilibrium Langmuir and Sips model were best fitted to the experimental data. Greatest amount of paracetamol adsorbed was noted in the assays with pH 2.0 and pHPZC to the carbons when compared to the assays with pH 11.0, due to electrostatic repulsion.