Extraction of Metal Ions Based on Aqueous Biphasic Systems

MEMBRANE EXTRACTION OF METAL IONS BASED ON AQUEOUS BIPHASIC SYSTEMS 

One study has been carried out in trying to adapt ABSs into a membrane separation technique for metal ions [69]. In this study, the PEG-rich phases from ABSs formed by mixing 40%. PEG-2000 (or PEG-6000) and 35%, (NH4)2S04 with and without NH SCN (4 x 10 M) were used as membranes. Thirty-five percent (NH i)2S04 with NH SCN was used as the metal-loading phase, and the sulfate solution without the extractant was used as the metal-receiving phase. The effects of various factors (pH of 

The results indicated that changes in the Eu and Zn concentrations in the metal-loading solutions during the membrane extraction are in keeping with the extraction data D. n Deu from this ABS. Zn is removed from the loading solution faster than Eu and thus is concentrated in the PEG-membrane under the experimental conditions (load solution [(NH4)2S0 = 35%, pH = 8 [metal ion] = 1 x 10 M [NH SCN] = 4 X 10 M receiving solution [(NH.,)2SO.i] = 35% [PEG-2000] = 35%). 

Although the studies on adapting PEG-ABSs into a membrane technique for metal ions are preliminary, it has been shown that the transfer of the metal ions through a PEG-rich phase membrane is comparatively fast and that it is possible to develop this technique for metal ion separations. More research is needed in this area to define fully the variables in this process and thus allow further practical development. 

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