Completely water insoluble resins containing different ligand groups were synthesized by radical polymerization in solution. The yield was higher than 78%. The resins were characterized by FT‐IR spectroscopy and thermal analysis. The retention properties at different pH were investigated by a batch method. Metal ions studied were: Cu(II), Cd(II), Zn(II), Hg(II), Pb(II), Cr(III), and U(VI). The retention properties were also tested under competitive conditions and were found to depend strongly on the pH. Elution of the metal ions was investigated in acid and basic media.

ABSTRACT:The ability of poly(N-vinylimidazole) hydrogels to bind Cu(II), Co(II), Ni(II), Zn(II), Cd(II), Pb(II), Hg(II), Na(I) and Ca(II) cations, as well as uranyl, vanadium, rhenium, and molybdenum complexes, was studied by a batch equilibrium procedure using atomic absorption spectroscopy and UV-Vis spectrophotometry. The optimum pH for ion adsorption was determined in any case. The influence of the crosslinking degree of the hydrogel on the sorption kinetics and the sorption capacity at equilibrium were also studied. Sorption from the binary mixture Cu(II) / U(VI) was also analyzed at the optimum pH. Elution of the ions adsorbed from single and binary solutions was achieved in all cases. A selective desorption of loaded hydrogels with two types of ions was attained. The general conclusion is that poly( N-vinylimidazole) hydrogels are excellent materials for retention of all the ions studied here [except for Pb(II), Na(I), and Ca(II)]. The elution, which can be selective, allows regeneration of the hydrogel.

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ABSTRACT:The binding ability of poly(4-vinylpyridine) hydrochloride resin for Cu(II), Cd(II), Zn(II), Hg(II), Pb(II), Cr(III), and U(VI) was investigated. All these ions, except Hg(II), could be not removed from aqueous solutions under the same conditions. The selective sorption of Hg(II) from mixtures of ions was observed. The elution of Hg(II) bound to the resin was also investigated using various concentrations of nitric acid and perchloric acid. Due to rapid complexation, a high mercury ion-binding capacity, high selectivity, and ease of regenerability, the resin can be useful for the removal and recovery of mercury ions from aqueous solutions.

SYNOPSISThe synthesis of a water-insoluble metal ion complexing resin was carried out by radical polymerization of 2,2-bis(acrylamido) acetic acid. The resin was characterized by elemental analyses, FTIR spectroscopy, and thermal analyses. The ability to bind copper(II), iron(II), iron(III), and uranium(V1) as well as the elution of the metal ions from the loaded resins were studied. For uranyl ions, pH 5 was the optimum sorption pH value. Sorption selectivity from the binary mixture Cu(I1) + U(V1) was studied at pH 2. The thermal stability is increased by adsorption of TJO;+. According to these results a coordination mechanism is suggested for sorption of copper and uranium. 0 1995 John Wiley & Sons, Inc.