Rapid adsorptive removal of toxic Pb2+ ion from aqueous solution using recyclable, biodegradable nanocomposite derived from templated partially hydrolyzed xanthan gum and nanosilica

This work studied the application of a novel biodegradable nanocomposite based on partially hydrolyzed polyacrylamide grafted xanthan gum and nanosilica (h-XG/SiO2) towards efficient and rapid removal of toxic Pb2+ ions from aqueous environment. The uptake ability of Pb2+ using h-XG/SiO2 has been studied in batch adsorption experiments with variation of adsorption parameters. The excellent removal rate (99.54% adsorption within 25 min) and superior adsorption capacity (Q(max) = 1012.15 mg.g(1)) of the composite material have been explained on the basis of synergistic and chelating effects of h-XG/SiO2 with Pb2+ ion through electrostatic interactions. The kinetics, isotherm and thermodynamics studies reveal that Pb2+ adsorb rapidly on nanocomposite surface, which is in agreement with pseudo-second-order kinetics and Langmuir adsorption isotherm models. In consequence of excellent adsorption as well as regeneration characteristics of nanocomposite, it has been found to be a promising adsorbent towards removal of Pb2+ ions from battery industry wastewater. (C) 2014 Elsevier Ltd. All rights reserved.