1993 Volume 19 Issue 2 Pages 279-287
The performance of a membrane extraction module, was analyzed for the mutual separation of Er and Y in the presence of a water-soluble complexing agent (DTPA), and the effects of various conditions on the membrane areas of extraction and scrubbing sections were studied.
It was confirmed that the required membrane areas decreased extremely by the addition of a complexing agent. There existed an optimum pH because pH influenced both complex formation equilibria in the aqueous phase and extraction ability. Moreover, selection of a porous support membrane with high permeability was found to be especially effective for improvement of membrane performance because the mass transfer through the porous support membrane was rate-determining in the scrubbing section. In the extraction section, the operating condition that the mass transfer with the dissociation of DTPA complex in the aqueous phase became the rate-determining step was desirable for obtaining high selectivity.
