Chapter 10 - Mass Transport in the Presence of a Fouling Layer

Abstract

Cake layers' properties can strongly depend on membrane structure and the membrane(s), and solute(s) physical/chemical properties. Accordingly, the foulant layer's structural properties can be very different. This study briefly surveys solute transport through a polarization layer and a fouling layer during pressure-driven membrane processes, where both diffusive and convective transports take place. Applying the diffusive plus convective fluxes across the fouling layer, solute transport is discussed in the presence of more transport layers, namely a polarization layer, a fouling layer, and an asymmetric membrane layer. Detailed analysis is given for mass transport during pressure-retarded osmosis and forward osmosis in the presence of a cake layer. The fouling layer is described similarly to the membrane support layer defining the cake layer's structural parameter. In such a way, the overall solute transport rate was defined by a single, explicit mathematical equation, taking into account all mass transport layers, namely the membrane active and support layers, external boundary layers, and the cake layer.