Chemical Engineering Journal, Vol.235, 100-108, 2014
Surfactant assisted nano-composite cation exchanger: Development, characterization and applications for the removal of toxic Pb2+ from aqueous medium
A novel nano-composite cation exchanger sodium dodecyl sulfate acrylamide Zr(IV) selenite (SDS-AZS) was developed by sol-gel method. The physico-chemical properties of SDS-AZS were studied using FTIR, TGA, XRD, SEM, EDX, TEM and elemental analyses. The material was effectively used for the removal of Pb2+ which is an important environmental pollutant. Batch experiments were performed as a function of various experimental parameters such as effect of pH (2-10), contact time (5-60 mm), SDS-AZS dose (0.1-1.0 g), initial Pb2+ concentration (10-30 mu g mL(-1)) and temperature (25-55 degrees C). The uptake rate of Pb2+ onto SDS-AZS was rapid and equilibrium established within 40 min. Kinetic studies showed better applicability for pseudo-first-order model. The applicability of Langmuir, Freundlich and Temkin isotherm models was investigated and the Freundlich isotherm exhibited the best fit with the experimental data. The values of thermodynamic parameters (Delta G degrees, Delta H degrees and Delta S degrees) were computed from the Van't Hoff plot which showed that the adsorption of Pb2+ was feasible, endothermic and spontaneous. The regeneration studies were carried out which demonstrated a decrease in the recovery of Pb2+ from 90% to 79% after four consecutive cycles. On the basis of good uptake capacity, SDS-AZS was successfully used for the removal and recovery Pb2+ from a real water sample spiked with Pb2+. (C) 2013 Elsevier B.V. All rights reserved.