Removal of Clofibric, Salicylic and Gallic Acids from Aqueous Solutions by Adsorption on a Commercial Activated Carbon

Abstract

The adsorption behavior of three pharmaceutical compounds and widespread used drugs, namely, clofibric acid, salicylic acid and gallic acid from aqueous solutions was investigated using an activated carbon, as adsorbent. This study aims to evaluate the performance efficiency of the proposed adsorbent commercial activated carbon for eliminate these organic compounds. The Freundlich, Langmuir, Temkin and Toth models were applied to the equilibrium data and in order to describe the adsorption behavior. It was found that the experimental data fitted well to the Langmuir model. It is also revealed that the adsorption of this compounds from the aqueous solutions on the activated carbon refer to the S-type by the Giles’s classification. In order to investigate the mechanism of adsorption, kinetic data were modelled using the pseudo-first- and pseudo-second-order kinetic model. The results showed that kinetic data followed closely to the pseudo-second order model.