COMPARATIVE STUDY ON THE SORPTION PERFORMANCES OF Cu(II), Co(II) and Cr(IH) BIFUNCTIONAL CHELATING ION EXCHANGERS WITH HYDROXAMIC AND AMIDOXIME GROUPS FOR HEAVY METAL IONS

摘要

Two new types of bifunctional chelating ion exchangers on the basis of ethylacrylate: acrylonitrile: divinylbenzene copolymers with hydroxamic acid and amidoxime groups have been evaluated for Cu(II), Co(II) and Cr(III)ions sorption from unbuffered diluted aqueous solutions. To model the retention and to compare the sorption capacity of bifunctional acrylic chelating sorbents for the tested cations the Langmuir and Freundlich isotherm equations have been used The Langmuir maximum sorption capacities for the sorbent of type A were determined to be 2.081, 1.423 and 1.384 mmole/g for Cu (II), Co (II) and Cr (III), respectively The increase of cross-linking degree for the bifunctional chelating ion exchanger of type В resulted in the decrease of its sorption capacity toward heavy metal ions under study. The negative values of AG in all cases indicate the spontaneous character of the sorption process. The kinetics of the Cu (II), Co (II) and Cr (III) sorption follow the Lagergren pseudo - first order model The results are significant for the future development of the tested sorbents into beneficial materials for industrial and environmental applications.