Influence of different resins on the amino acid recovery by resin-filling electrodialysis

Compared to the concentration and separation of inorganic salts, recovery of amino acids by electrodialysis (ED) is normally more difficult due to their weak dissociation ability, relatively complex structure and zwitterionic properties. In this work, three kinds of resins, inert resin, 001 x 4 resin (strongly acidic) and 201 x 4 resin (strongly basic), were added in the diluted compartments of membrane stack to facilitate the transport of amino acids. The effect of the property and quantity of resin-filling on the ED behavior of glutamate (acidic) and lysine (basic) was investigated respectively. It was found that the promotion effect of different resins on the transport of amino acids was in this order: 201 x 4 > 001 x 4 >= inert resin. For inert resin, when the percentage of resin filling in the compartments reached 25% or 50%, the improvement in transport of amino acids was most significant. This was attributed to the influence of resins on the hydraulic conditions in the diluted compartments. As for 201 x 4 and 001 x 4 ion exchange resins, the higher quantity of resin-filling produced more obvious positive effect on the migration of amino acids as compared to inert resin, which was caused by the superior conductive and catalytic ability of the functional groups. (C) 2015 Elsevier B.V. All rights reserved.