Journal of Hazardous Materials, Vol.182, No.1-3, 363-370, 2010
Combined cation-exchange and extraction chromatographic method of preconcentration and concomitant separation of bismuth(III) with high molecular mass liquid cation exchanger
A selective method has been developed for the extraction chromatographic separation of Bi-III with Versatic 10 coated on silanized silica gel (SSG). Bi-III has been quantitatively extracted from 0.1 M acetate buffer at the range of pH 5.0-5.5. The result showed that the solution pH, influent volume, flow-rate and solution temperature would affect the sorption of Bi-III. The sorbed Bi-III was eluted with 0.1 M H2SO4. The extractor system has got good values of exchange capacity (1.42 meq. of H+ g(-1) of dry exchanger at 25 degrees C), breakthrough capacity (19.75 mg g(-1) at pH 5.5) and column efficiencies (300) with respect to Bi-III. The positive value of Delta H (12.63 kJ mol(-1)) and Delta S (0.271 kJ mol(-1) K-1) and negative value of Delta G (-68.241 kJ mol(-1)) indicated that the sorption process was endothermic, entropy gaining and spontaneous in nature. P.F. has been optimized at 76.4 +/- 0.3 and the desorption constants K-desorption (8 x 10(-3)) and K-desorption' (1.4 x 10(-1)) have been determined. R-f values and selectivity factors for diverse metal ions with respect to that of Bi-III have been determined by ion-exchange paper chromatography. Bi-III has been separated from synthetic mixtures containing its congeners and other metal ions associated with it in ores and alloy samples. The method was found effective for removal of Bi-III from different water samples. A plausible mechanism for the extraction of Bi-III has been suggested. (C) 2010 Elsevier B.V. All rights reserved.
Keywords:Extraction chromatography;Versatic 10;Preconcentration;Selectivity factors;Selective separation of Bi-III