Synthesis and characterization of PVP/AAc copolymer hydrogel and its applications in the removal of heavy metals from aqueous solution

Chelating poly(vinylpyrrolidone/acrylic acid) (PVP/AAc) copolymer hydrogels were prepared by radiation-induced copolymerization. The effects of preparation parameters such as PVP content in the hydrogel and irradiation dose on the swelling behavior of the hydrogel were studied. The pH dependent swelling was investigated. The thermal stability of the prepared hydrogel and the metal chelated ones was characterized by TGA. The removal of Fe(III), Cu(II), and Mn(II) from aqueous solution by the prepared PVP/AAc chelating hydrogel was examined by batch equilibration technique. The influence of treatment time, pH, and the initial feed concentration on the amount of the metal ions removed was studied. The results show that the removal of the metal ion followed the following order: Fe(III) > Cu(II) > Mn(II). The amounts of the removed metal ions increased with treatment time and pH of the medium. To re-use the hydrogel, the metal ions were stripped by using 2 N HCl.