Removal of environmentally impacting metal ions using functional resin poly(4‐styrene sulfonate‐co‐4‐vinylpyridine): Synthesis and metal ion retention properties

A water‐insoluble polymer, poly(sodium 4‐styrene sulfonate‐co‐4‐vinylpyridine), was synthesized by radical polymerization at different amounts (2, 4, 6, and 8 mol %) of crosslinking reagent (CR). The polymerization yield ranged from 83.5% to 100.0%. The resin is characterized by FT IR spectroscopy, thermal analysis, and scanning electron microscopy. The water absorption capacity, WAC (110 g/g dry resin), was obtained for the resin with a 2 mol % of CR. The metal ion affinity is studied by Batch equilibrium procedure under different experimental conditions for the cations: Hg(II), Cd(II), Zn(II), Pb(II), Cr(III), and Al(III). The metal ion affinity increased as the pH increased. At pH 5, the resin presented an affinity above 90% for all metal ions. Hg(II) presented the highest retention value at pH 2. The maximum metal ion retention capacity is determined at optimum pH for Hg(II), Cd(II), Pb(II), and Zn(II).