Solute adsorption and gel layer formation during ultrafiltration of ovalbumin

Abstract

To define the influence of osmotic pressure, solute adsorption, and gel layer formation on permeate flux during the ultrafiltration of an ovalbumin solution, the characteristics of the gel-like layer formed on the membrane surface were investigated and the adsorption rate of ovalbumin to membranes was measured under different conditions. Gel-like layer observed on the membrane surface was found to be a deposit layer formed by an aggregate of denatured ovalbumin which could be precipitated by centrifuga- tion. This layer had a rejection ability for ovalbumin itself and little resistance for permeate flow. In both cases where there is a layer and where is not, the flux values during the ultrafiltration could be precisely predicted by the osmotic pressure and adsorption resistance model which took into account the influence of osmotic pressure and solute adsorption. The forced flow of solution into membrane pores shortened the time to reach adsorption equilibrium, suggesting a notable influence of solute adsorption into membrane pores.