摘要
A three-step treatment (thermal, chemical and activation) has been developed to effectively transform scrap tire carbons (STCs) into highly-pure activated carbons (HP-AC). The as-prepared HP-AC displays a specific surface area of 1048 m(2)/g (total pore volume of 1.16 cm(3)/g) with a yield of 21.4 wt%. Adsorption of methylene blue (MB) using HP-AC from aqueous solution under equilibrium and kinetic conditions was evaluated by varying initial MB concentration (0.15-20 ppm), contact time (0-120 min), solution pH (2-12) at 30 degrees. The Langmuir isotherm model shown better fit to the equilibrium results than the Freundlich model. The adsorption capacity (q(m)) of HP-AC is 323 mg/g. The kinetic adsorption results were well described by the pseudo-second-order model. XPS results reveal that electrostatic interaction between the oxygenated functional groups on HPAC and MB is suggested as the main driving force for the adsorption process. This study demonstrates that HP-AC is an effective and low-cost adsorbent for the removal of MB from aqueous solution. (C) 2017 Elsevier B.V. All rights reserved.