Simulation of unstirred batch ultrafiltration process based on a reversible pore-plugging model

An unsteady state mass transfer model has been developed taking into account the effect of reversible pore plugging by the diffusing solute molecules. The osmotic pressure model has been used to predict the membrane surface concentration. The rate of available fractional area of the membrane that is blocked at any time due to pore plugging phenomenon has been assumed to be the function of dimensionless membrane surface concentration prevailing at that time. Experimental data generated in this study using cellulose acetate membrane of 5000 MWCO and polyethylene glycol (PEG)-6000 as solute in unstirred batch configuration has been used to find the appropriate nature of the above-mentioned function. Once the functional dependency between the rate of fractional area blocked and dimensionless membrane surface concentration has been found, it can be used to simulate flux and rejection behaviour during unstirred batch ultrafiltration (UF). The predicted results show very good agreement with the experimental data and the average deviations for all the cases are found to be well within +/-10%. (C) 2000 Elsevier Science B.V. All rights reserved.