Resistance in series model for ultrafiltration of mosambi (Citrus sinensis (L.) Osbeck) juice in a stirred continuous mode

Flux decline during ultrafiltration (UF) of depectinized mosambi juice was quantified by a resistance-in-series model. Resistance against the solvent flux was assumed to be comprised of four components, namely, membrane hydraulic, adsorption, pore plugging and fouling resistance. Apart from the membrane hydraulic resistance, evolution of each of these resistances with time was determined from separate set of experiments independently. The experiments were conducted in a stirred continuous mode both under low as well as high polarization conditions. The range of operating transmembrane pressure drop in the experiments was 276–552 kPa and that of Reynolds number was 1.4–2.1 × 105. Correlations were proposed to quantify the growth kinetics of the resistances, separately. Finally, the profile of total resistance and corresponding flux decline were calculated and compared with the experimental data. The adsorption resistance was found to be about 60% of membrane hydraulic resistance. The pore blocking resistance was about the same as that of membrane resistance at higher Reynolds number and was about four times at lower Reynolds number. The fouling resistance was about six to ten times the membrane resistance in the range of operating conditions, studied herein.