Effect of the Mass Fraction of Ion-Exchange Resin in a Ralex CM Cation-Exchange Membrane on Demineralization of Phenylalanine Aqueous Salt Solutions by Neutralization Dialysis

Васильева, В. И.; Saud, Ali M.; Акберова, Э. М.

doi:10.1134/s2517751621020074

Cited by 4 publications

(3 citation statements)

References 17 publications

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“…In order to reduce the loss of Phe, it is necessary to ensure the reagent-free pH control in the D compartment so that the pH value is as close as possible to the pI of the amino acid. Based on the literature [ 8 , 10 , 17 , 18 ], pH can be controlled by influencing the ion exchange rate (ion fluxes) across the CEM and AEM. This may be realized in several ways: by the selection of membranes with desired properties (structure, thickness, ion-exchange capacity, nature of fixed ion-exchange groups, etc.…”

Section: Resultsmentioning

confidence: 99%

“…Of particular interest is the use of ND for the separation of multicomponent mixtures and the separation of pure valuable components. This method has shown its effectiveness for the separation of weak acids and bases [ 7 ], isolation of mono-, oligo- and polysaccharides [ 8 ], aldehydes [ 9 ], and amino acids [ 8 , 10 , 11 ]. Another prospect for ND may be its application for the separation of organic and mineral compounds as a pretreatment step for electrodialysis processing of liquids of biological origin, for example, whey.…”

Section: Introductionmentioning

confidence: 99%

“…However, maintaining the required pH value of the solution being desalted is a demanding task. This value is influenced by a large number of parameters of ion-exchange membranes (for example, the ion-exchange capacity, nature of functional groups, thickness, degree of matrix crosslinking) and of the ND process (concentration and flow rate of acid, alkali solutions, and solution being desalinated in the corresponding compartments) [ 5 , 10 , 11 , 14 , 15 ]. In contrast to ampholyte-containing solutions, the mechanisms of strong electrolyte ions transfer during the ND have been studied sufficiently to gain a comprehensive idea of what trends the pH of the solution being desalted obeys.…”

Section: Introductionmentioning

confidence: 99%

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Phenylalanine Losses in Neutralization Dialysis: Modeling and Experiment

et al. 2023

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A non-steady state mathematical model of an amino acid (phenylalanine (Phe)) and mineral salt (NaCl) solution separation by neutralization dialysis (ND) carried out in a batch mode is proposed. The model takes into account the characteristics of membranes (thickness, ion-exchange capacity, and conductivity) and solutions (concentration, composition). As compared to previously developed models, the new one considers the local equilibrium of Phe protolysis reactions in solutions and membranes and the transport of all the phenylalanine forms (zwitterionic, positively and negatively charged) through membranes. A series of experiments on ND demineralization of the NaCl and Phe mixed solution was carried out. In order to minimize Phe losses, the solution pH in the desalination compartment was controlled by changing the concentrations of the solutions in the acid and alkali compartments of the ND cell. The validity of the model was verified by comparison of simulated and experimental time dependencies of solution electrical conductivity and pH, as well as the concentration of Na+, Cl− ions, and Phe species in the desalination compartment. Based on the simulation results, the role of Phe transport mechanisms in the losses of this amino acid during ND was discussed. In the experiments carried out, the demineralization rate reached 90%, accompanied by minimal Phe losses of about 16%. Modeling predicts a steep increase in Phe losses when the demineralization rate is higher than 95%. Nevertheless, simulations show that it is possible to achieve a highly demineralized solution (by 99.9%) with Phe losses amounting to 42%.

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