Adsorption of methylene blue onto Platanus orientalis leaf powder: Kinetic, equilibrium and thermodynamic studies

In this study, the potential of Platanus orientalis leaves powder (PULP) to remove methylene blue (MB), a cationic dye, from aqueous solution was evaluated. Morphology of adsorbent surface and the nature of the possible PULP and MB interactions were examined by the SEM micrograph and FTIR technique, respectively. The effects of contact time, initial dye concentration, temperature and solution pH on the MB adsorption were investigated. The adsorption was analyzed using different isotherms and kinetic models. The results showed that the adsorption isotherm data were fitted well to the Langmuir isotherm and adsorption kinetics followed the pseudo-second-order model. The thermodynamic parameters, such as Delta G degrees, Delta H degrees and Delta S degrees, were also evaluated. The calculated parameters indicated that adsorption process was spontaneous and endothermic in nature. Recycling efficiency of PULP was also investigated for the removal of MB. The adsorption capacity of MB onto PULP found to be as high as 114.94 mg/g, which is higher than the adsorption capacity of a number of recently studied in the literature potential adsorbents. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.