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 25min) and superior adsorption capacity (Q_max=1012.15mgg^-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.