Filtration of protein colloids by fibrous membranes: A mechanistic investigation using packed bed filtration approach

•BSA filtration by the fibrous membranes was simulated with column filtration.•Microfiltration and column filtration yielded similar attachment efficiencies.•Membrane fouling was the most severe at pH close to the isoelectric point of BSA.•BSA–BSA interactions strongly affected its removal by microfiltration.

This research aimed to use packed bed filtration as a novel approach to investigate fibrous membrane filtration of aqueous particles, a novel environmental application of fibrous materials and a new frontier for engineering colloidal science. For this purpose, bovine serum albumin (BSA) was filtered through a pre-characterized glass bead column to determine attachment efficiencies (α) of BSA onto glass beads. Subsequently, BSA was filtered through a glass-fiber membrane possessing similar surface elemental compositions as the glass beads. By simulating the glass fiber membrane as a packing of spherical glass particles with a diameter equivalent to fiber diameter, α values pertinent to BSA-glass fiber attachment were calculated using the clean bed efficiency model. A side-by-side comparison of the α values show that membrane filtration exhibited greater α values than column filtration, the α values calculated for membrane filtration were always about 1.5 times of those determined under similar conditions in column filtration. However, α values for the two systems varied with solution chemistry in similar trends and the maximal α values for both systems were both found at the isoelectric point of BSA (pHIEP = 4.78). This finding implies that fibrous membrane filtration may be studied using classical packed bed filtration theories.

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