Mechanism of centrifugal filtration for separation of microbe/protein bio-suspension

The mechanism of centrifugal filtration of microbe/protein bio-suspension is studied. The bio-suspension is prepared by adding baker yeast and albumin bovine serum (BSA) into a buffer solution at pH 7.0; and the BSA molecules are purified from the mixture in a swing-arm centrifuge under rotational speeds ranging from 500 to 4000 rpm. A numerical program is established for estimating the concentration profiles of yeast cells in the filter chamber, the cake growth rate, the cake properties and filtration rate. The variations of the average specific filtration resistance and average porosity of cake are estimated based on a Voigt-in-series compression model. The simulated results of cake properties and filtrate rate agree fairly well with the available experimental data. In addition, the separation efficiency of BSA can be predicted accurately under various conditions once the BSA permeation through the cake and the filter septum is analyzed. To compare the separation efficiency of BSA in the centrifugal and cross-flow microfiltration systems, use of centrifugal filtration with a centrifugal effect just over the critical value is an optimum on the viewpoint of operating time, separation efficiency, and energy-saving.