Modified PVP based hydrogel: Synthesis, characterization and application in selective abstraction of metal ions from water

Graft copolymerization and simultaneous crosslinking of polyvinyl pyrrolidone (PVP) have been carried out by microwave assisted method. The pore size and thus the functional properties of hydrogels were customized exclusively for Cr(VI) and As(III) ions abstraction by varying the concentrations of monomer and crosslinker, thus enabling selective entrapment. The hydrogels have been Characterized through ESR at different temperatures and pH and also through FTIR, TGA, SEM, Elemental analysis. Selectivity of hydrogels for Cr(VI) and As(III) ions abstraction from spiked water samples have been evaluated in presence of Na+, Ca2+ and Mg2+ ions at different contact times. The results indicate that hydrogels have selective capability for Cr (VI) and As (III) ion abstraction from water without abstraction of other ions present in water like Ca2+ and Mg2+ ions (natural and essential ions in potable water). The experimental equilibrium data have been analyzed by Langmuir isotherm model and the characteristic parameters for the isotherm have been evaluated. The result of rate kinetics for the entrapment of Cr-VI ions have been found best fitted with pseudo-second order kinetics model. (C) 2017 Elsevier B.V. All rights reserved.