Reactive green HE-4BD functionalized supermacroporous poly(hydroxyethyl methacrylate) cryogel for heavy metal removal



The aim of this study was to investigate the heavy metal adsorption performance of supermacroporous poly(hydroxyethyl methacrylate) [PHEMA] cryogel. The PHEMA cryogel was produced by cryo-polymerization. The PHEMA cryogel was characterized by scanning electron microscopy (SEM). The PHEMA cryogel containing 385 μmol Reactive Green HE-4BD/g were used in the adsorption studies. Adsorption capacity of the PHEMA cryogel for the metal ions, i.e., Cu2+, Cd2+, and Pb2+ were investigated in aqueous media containing different amounts of the ions (5–600 mg/L) and at different pH values (3.2–6.9). The maximum adsorption capacities of the PHEMA cryogel were 11.6 mg/g (56 μmol/g) for Pb2+, 24.5 mg/g (385 μmol/g) for Cu2+ and 29.1 mg/g (256 μmol/g) for Cd2+. The competitive adsorption capacities were 10.9 mg/g (52 μmol/g) for Pb2+, 22.1 mg/g for Cd2+ (196 μmol/g) and 23.2 mg/g (365 μmol/g) for Cu2+. The PHEMA/Reactive Green HE-4BD cryogel exhibited the following metal ion affinity sequence on molar basis: Cu2+ > Cd2+ > Pb2+. The PHEMA/Reactive Green HE-4BD cryogel can be easily regenerated by 50 mM EDTA with higher effectiveness. These features make the PHEMA/Reactive Green HE-4BD cryogel a potential adsorbent for heavy metal removal. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010