An experimental research of the absorption properties of metal ions onto synthetic hydrogel obtained by solution polymerization of acrylic acid and itaconic acid in presence of N,N'-methylenebisacrylamide as crosslinking agent was carried out. The swelling behavior in aqueous salt solutions was studied as a function of divalent cation concentration (Cu2+, Zn2+, Ni2+, Co2+, Cd2+, Pb2+, Hg2+) in the external solution ranging from 10degrees to 1M, at 25degreesC. The ability of these hydrogels to bind cations was measured at different pH values and metal ion concentrations. (C) 2003 Wiley Periodicals, Inc.