Adsorption of divalent lead ions from aqueous solution using low silica nano-zeolite X

The studies on adsorption of divalent lead from aqueous solution were conducted by varying various parameters such as contact time, pH, adsorbent dosage, concentration of adsorbate and temperature. The maximum adsorption efficiency was obtained in a contact time of 100 min, pH of 3.5-5, adsorbent dosage of 1.5 g/L, adsorbate concentration of 15 mg/L and temperature of 318 K. The adsorption kinetic of Pb2+ onto low silica nano-zeolite X was discussed using different models and the pseudo-second order model provided the best correlation of the experimental data. Langmuir and Freundlich adsorption isotherms were employed in order to evaluate the optimum adsorption capacity of the adsorbent. Low silica nanozeolite X was found to be very effective and reached equilibrium in 100 min. The adsorption capacity of Pb2+ on low silica nano-zeolite X was found to be 909.09 mg/g in the optimum condition. The rate constant and thermodynamic parameters were calculated. (C) 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.