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

•Biodegradable anionic adsorbent h-XG/SiO2 exhibits excellent Pb2+ uptake capacity.•Adsorption capacity is significantly higher than those of reported adsorbents.•h-XG/SiO2 removes Pb2+ considerably from battery industry effluent.•The nanocomposite showed excellent regeneration characteristics.

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 (Qmax = 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.

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