Modification of the commercial carrier in supported liquid membrane system to enhance lactic acid flux and to separate l,d-lactic acid enantiomers

Abstract

Enhancement of lactic acid transmembrane flux through a supported liquid membrane system by using a modified carrier is first time demonstrated in this work. The results show that with the replacement of the chloride ion with a carbonate one in the commercial quaternary ammonium salt (Aliquat™ 336), the lactic acid fluxes are always higher at the correspondingly same volume ratio of extractants in kerosene. In addition, enhanced enantiomer separation of l,d-lactic acid mixtures is also achieved by adding β-cyclodextrin into the feed in the supported liquid membrane system. The separation factor is as high as 2.3 in both ideal and racemic mixture tests with an impressively high transmembrane flux. © 2007 Elsevier B.V. All rights reserved.