FLUX DECLINE IN CROSS-FLOW MICROFILTRATION AND ULTRAFILTRATION - MECHANISMS AND MODELING OF MEMBRANE FOULING

Flux decline in crossflow ultrafiltration and microfiltration was inve stigated by perceiving membrane fouling as a dynamic process from non- equilibrium to equilibrium. Under the influence of the boundary condit ion at the initial section and cross flow, the equilibrium is first re ached at the initial section of the crossflow filter and the front of the equilibrium region progresses with time toward the end of the filt er. A mathematical model was developed to describe this dynamic proces s and a closed-form solution of the model was provided. With the model , the time-dependent flux and the time required to reach the steady st ate in a crossflow filtration can be easily determined. The fouling pr ocess under different conditions is simulated as an illustration and d emonstration of the newly developed model. (C) 1998 Elsevier Science B .V.