Application of AlMCM-41 for competitive adsorption of methylene blue and rhodamine B: Thermodynamic and kinetic studies

AlMCM-41 was applied for adsorption of methylene blue (MB) and rhodamine B (RB) in single and binary component systems. In the single component systems. AlMCM-41 represents higher adsorption capacity for MB than RB with the maximal adsorption capacity of 2.08 x 10(-4) and 8.74 x 10(-5) mol/g at 25 degrees C for MB and RB, respectively. In the binary component system, MB and RB exhibit competitive adsorption onto the adsorbent. The adsorption is approximately reduced to 94 and 79% of single component adsorption systems for MB and RB (initial concentration of 8 x 10(-6) M) at 25 degrees C. In single and binary component systems, kinetic and adsorption isotherm studies demonstrate that the data are following pseudo-second-order kinetic model and Langmuir isotherm. Effect of solution pH on the adsorption in single and binary component systems was studied and the results were described by electrostatic interactions. (C) 2010 Elsevier B.V. All rights reserved.