Prediction of rejection in ultrafiltration of macromolecular solutes

A mathematical model based on steady-state mass balance over a boundary layer, coupled with the results from irreversible thermodynamics, is proposed in the present study for ultrafiltration of PEG-6000 rising a cellulose acetate membrane. The model is capable of predicting both the membrane surface concentration and permeate concentration, and can be utilized to predict the value of rejection at any operating condition. Three parameters (solvent permeability, solute permeability, and reflection coefficient) were taken into account while developing this model, These parameters, along with the known values of operating conditions and solution properties, allow prediction of rejection. The computed results are in good agreement with the previously published experimental data of Bhattacharjee and Bhattacharya.