Analysis of proteins transmission in vortex flow ultrafilter for mass transfer coefficient

Abstract

Dilute solutions of two proteins, bovine serum albumin (BSA) and ovalbumin, were ultrafiltered through a hydrophilic ultrafiltration membrane with molecular weight cutoff (MWCO) of 100,000 in a vortex flow module. The protein transmission data were carefully analyzed as a function of pressure at different rotational speed of the membrane. So long as the protein concentration was less than 10 g/l there was a pressure range for each rotational speed where true (or intrinsic) transmission coefficient of the membrane was found constant. Using concentration polarization model and the condition of constant true transmission coefficient, it was possible to calculate the mass transfer coefficient of the system. The mass transfer coefficient calculated by this method compares well with the literature values. The method described here has the advantage over velocity variation method as the mass transfer coefficient dependence on cross-flow velocity was not assumed a priori. The necessary conditions for the application of this method are clearly spelt out and discussed in detail. The true transmission coefficient calculated by this method may, perhaps, serve as a guideline in characterizing high flux ultrafiltration membrane. The true transmission coefficient of BSA and ovalbumin through 100 K MWCO membrane was between 0.03 to 0.05 and 0.11 to 0.15, respectively.