Removal of atenolol by adsorption-Study of kinetics and equilibrium

Atenolol is a beta-blocker drug widely consumed for treatment of cardiovascular diseases. Approximately 50% of the amount ingested by humans is excreted without any change in its chemical structure. For this reason, this drug has been commonly found in many environmental matrices, like hospital wastewater. The objective of this study was to evaluate the removal of atenolol in aqueous solutions by adsorption process using granular activated carbon as solid adsorbent. Adsorption experiments were performed in batch evaluating the effect of pH and contact time parameters. Kinetic of atenolol adsorption in granular activated carbon was evaluated using pseudo-first and pseudo-second order models. Equilibrium isotherms for this system were analyzed by Langmuir and Freundlich models. The best results found in the adsorption experiments were pH 6, 90 min of contact time. Pseudo-second order was the kinetic model that best described the adsorption of atenolol. Under these conditions it was possible to obtain an efficiency removal of approximately 88%. Freundlich was the best model that fit the experimental data. Results indicate that the proposed process represents significant potential for removal of this contaminant. (C) 2017 Elsevier Ltd. All rights reserved.