DESALINATION OF PHENYLALANINE SOLUTION BY ELECTRO MEMBRANE METHODS

Abstract

Desalination of phenylalanine solution with mineral salt impurity by electro membrane methods is studied in this paper. The parameters of desalination efficiency such as desalination degree and ampholyte losses in electrodialysis with empty deionization channel and with spacers are compared in the process of desalination of solution containing phenylalanine and sodium chloride.

The experiments have been carried out in a seven compartment electrodialyzer with heterogeneous monopolar ion-exchange membranes. Electrodialysis cell has equipped with anion-exchange membranes MA-41 and cation-exchange membranes МК-40 manufactured by “Shchekinoazot” Ltd, Russia. Two types of spacers are filled in desalination compartment.

An inert filler – styrene-divinylbenzene copolymer as turbulator in electrodialysis cell is used to achieve larger value of the desalination degree than that for laminar fluid flow in the desalting channel of electrodialyzer. The high values of the desalination degree of mixed solution Phe+NaCl are reached at current densities below the limiting one by using EDI. This method can be used as more energy-saving technology.

The mass transfer of organic ampholyte ions through ion-exchange membranes depends on the solution pH of the desalting section. In electrodialysis with spacers in desating channel the value of the limiting current density increases and the change of solution pH of deionization compartment decreases. This is due to the reducing of the diffusion limitation of ions movement from bulk solution to the membrane surface.

Desalination of amino acid solution by electrodialysis with ionconductive and nonconductive spacers is more perspective for obtaining of amino acids solutions with a higher degree of purity.

ACKNOWLEDGEMENTS

The work was supported by the "Foundation for Assistance to Small Innovative Enterprises in Science and Technology", the program "UMNIK" contract 10032GU2/2015.