Synthesis of poly(acrylamide-co-4-vinylpyridine) hydrogels and their application in heavy metal removal

A series of poly(acrylamide-co-4-vinylpyridine) hydrogels having varied acrylamide/4-vinylpyridine content and different crosslink ratios of N,N'-methylene-bisacrylamide was prepared by using solution polymerization. The prepared hydrogel polymers were characterized by their elemental analysis, infrared spectroscopy, and equilibrium water content. The polymers were investigated toward metal ion uptake of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). The polymers were more sensitive to Cu(II) and Ni(II) and the order of metal ion binding was Ni(H), Cu(II) > Zn(II) > Co(II) > Mn(II). Metal ion uptake by the polymers was reduced as the pH of the medium decreased. Recycling of the resins resulted in high recovery of the metal ions from their aqueous solutions. (C) 2003 Wiley Periodicals, Inc.