Polarographic determination of uranyl adsorption onto poly(acrylamide-g-ethylenediaminetetraacetic acid) hydrogels in the presence of cadmium and lead

Poly(acrylamide-g-ethylenediaminetetraacetic acid) [P(AAm-g-EDTA)] hydrogels with various compositions were prepared from ternary mixtures of acrylamide, ethylenediaminetetraacetic acid and water by using Co-60 gamma-rays. This study showed that P(AAm-g-EDTA) hydrogels adsorb heavy metal ions such as UO22+ in the presence of Pb2+ and Cd2+ selectively at certain pH's. The external stimuli of pH, temperature and ionic strength play an important role on the adsorption behavior. Since a very sensitive electro-analytical technique, differential pulse polarography (DPP) was used for determination of UO22+ adsorbed onto hydrogels (0.1-3.2 mg/g dry gel) from 5.0 mg/l aqueous solution without interfering Pb2+ and Cd2+ at certain pH's. These hydrogels can be used directly as UO22+ selective adsorbent for water and environmental pollutants without any pre-concentration techniques. (C) 2003 Elsevier B.V. All rights reserved.