Application of activated carbon as adsorbents for efficient removal of methylene blue: Kinetics and equilibrium study

In this study, activated carbon (AC) as novel adsorbent was prepared from low cost and locally available source such as peanut sticks wood. The surface properties of this new adsorbent were identified with various techniques such as FT-IR, BET and SEM analysis. The pore size of this new adsorbent was lower than 20 nm and with high Langmuir absorption capacity. Subsequently, the activated carbon (AC) was applied for the removal of methylene blue (MB) from aqueous solutions. It was found that removal percentage significantly depend to the level of initial solution pH and dye concentration, temperature and adsorption time. In all stages, the variables effect was studied by one at a time method. Among the various conventional isotherm models, Langmuir-Freundlich is more suitable for analyzing the explanation data. The calculated thermodynamic parameters indicate the entropy-driven and endothermic nature of MB removal process. The experimental data at various times was evaluated and modeled by different kinetic equation such as pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models according to correlation coefficient, it was found that the kinetic data follow the Elovich equation. (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.