Concentration polarization during nanofiltration of whey ultrafiltration permeate
Authors:
Sergey A. Titov, Vitaly Yu. Ovsyannikov, Dina V. Klyuchnikova, Konstantin A. Velitchenko
Abstract:
Baromembrane methods for concentrating secondary milk raw materials solve a number of pressing problems in the dairy industry, such as preserving biologically valuable substances, reducing environmental pollution from production waste, and lowering transportation costs. When extracting protein from whey using ultrafiltration, the byproduct is permeate, which is dried after being concentrated. This study examines the factors leading to membrane surface deposition during nanofiltration permeate concentration. Nanofiltration studies of model solutions revealed that membrane permeability, as well as the ratio of ion concentrations in the permeate and concentrate, are lower in calcium chloride solutions compared to sodium and potassium chlorides, due to the accumulation of anions at the membrane surface due to its charge. A model solution with the same ionic composition as the permeate, as well as calcium lactate solutions, are characterized by higher permeability than the other solutions, due to the charge state of the complexes formed in the boundary layer. This is confirmed by a decrease in ionic permeability with filtration time, as well as a drop in solution permeability with increasing concentration, even in the range of 1–2%. The ion concentration in the filtrate during filtration of these solutions decreases over time, due to complex formation and precipitate formation on the membrane surface. The intensity of precipitate formation depends on the pH of the solution and is minimal at pH 6.5–7. During permeate filtration, a dense precipitate with low ion permeability forms, which is not washed away by tangential flow. Moreover, the membrane permeability to distilled water irreversibly decreases from 80 to 21 dm³/(m²∙h). The increased viscosity of the boundary layer in the presence of lactose with a mass fraction of 4.83% can explain this. The rate of precipitate formation increases with increasing solution concentration.
Keywords:
whey; concentration polarization; ultrafiltration; permeate; nanofiltration; baromembrane processes
For citation:
Titov S.A., Ovsyannikov V.Yu., Klyuchnikova D.V., Velitchenko K.A. Concentration polarization during nanofiltration of whey ultrafiltration permeate. Индустрия питания|Food Industry. 2026. Vol. 11, No. 2. Pp. 45–54. DOI: 10.29141/2500-1922-2026-11-2-5. EDN: DUKOBF.
