An Investigation on the Performance of Nanostructure Poly-Ether-Sulfone Hollow Fiber Membrane in Concentration and Purification of Whey

Whey is a by-product of dairy industries along cheese production. As a raw material, whey has several applications in food industries and its valuable protein and lactose contents. Membrane technology, more specifically ultrafiltration (UF), is being used in dairy industry to produce whey protein concentrate (WPC) because this technology allows selective separation of whey proteins compared to the rest of its components. In this regard, the objective of this research was to investigate the effects of different operating parameter on whey protein concentration and purification process using ultrafiltration membranes.

Three different nanostructure Poly-Eether-Sulfone (PES) hollow fiber membranes were tested and the effects of operating parameters, temperature (43 oC), three different pressures (1 bar, 2 bar, 3 bar) and feed flow rate on the permeate flow rate, protein rejection and lactose permeation were studied.

Results showed that pressure increase enhances the permeation flow rate which is more sensible at lower pressures. Moreover, high pressures have not been considered suitable considering higher fouling and lower flux recovery. Increasing feed flow rate resulted in higher turbulence on the surface of the membrane and reduces the membrane fouling and enhances the permeation flow rate even though these parameters (pressure and feed flow rate) did not have any significant effect on the protein rejection and lactose permeation. At the best operating conditions, maximum protein rejection was %91.01.

considering the findings, it can be concluded that UF process using PES hollow fiber membrane is capable of performing desired separation and purification of whey.