SEPARATION OF AMINO-ACIDS BY ELECTRODIALYSIS WITH ION-EXCHANGE MEMBRANES

The selective separation of amino acids, glutamic acid, methionine and lysine, from their solution mixture was examined by electrodialysis w ith ion-exchange membranes, SELEMION-CMV and SELEMION-AMV, under condi tions of pH 1 to 12 and current densities of 0 to 15 A/m(2). The amino acids were almost completely separated from each other under the cond itions studied: Only glutamic acid is transported across the anion-exc hange membrane; only lysine across the cation-exchange membrane; and m ethionine is not transportaed at all, Their fluxes across the membrane s have maxima in the neutral pH range, increasing almost linearly with current density, A model for explanation of the experimental results has been proposed considering solution equilibrium, ion-exchange equil ibrium and diffusion in the membranes, Successful simulation has confi rmed the amino acid transport mechanism which was proposed in the mode l, The diffusivities of ionic species, model parameters, have been det ermined, Moreover the role of each ionic species in carrying current a nd the effect of water splitting are also discussed.