Adsorption behavior of estrogenic compounds on carbon nanotubes from aqueous solutions: Kinetic and thermodynamic studies

In this study different estrogenic compounds, estrone (El), 17 beta-estradiol (E2), and 17a-ethinylestradiol (EE2), were removed from the model and real solution by the newly emerged multi-walled carbon nanotubes. The effects of different factors which affect the removal process were studied and optimized for efficient removal. The kinetics of E1, E2, and EE2 adsorption on MWCNTs were analyzed using different kinetic models and the results showed that the removal was mainly a pseudo-second-order process. The thermodynamic study showed the spontaneity and exothermic nature of the removal process, with negative entropy. (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.