TY - JOUR T1 - Effect of Transmembrane Pressure on Fouling and Membrane Performance During Ultrafiltration of Milk TT - بررسی اثر فشار بر کارایی و گرفتگی غشا در عمل فراپالایش شیر JF - JCPP JO - JCPP VL - 10 IS - 2 UR - http://jcpp.iut.ac.ir/article-1-553-en.html Y1 - 2006 SP - 191 EP - 202 KW - Milk KW - Ultrafiltration KW - Concentration polarization KW - Fouling KW - Resistance-in -series KW - Flux and retention. N2 - In this study, the effect of transmembrane pressure (TMP) on flux decline and protein rejection due to concentration polarization and fouling (adsorption) resistances during ultrafiltration of reconstituted skimmilk was investigated. UF experiments were carried out using a pilot plant unit equipped with spiral wound module and polysulfonamide UF membrane. A three-stage experimental strategy based on a resistance-in-series model (boundary layer-adsorption) was used to seperately determine the hydraulic membrane resistance, concentration polarization and fouling resistances. The results showed that increasing TMP had no effect on initial flux reduction (Jrt), but flux decline in each TMP was greatly due to concentration polarization, and fouling has a small role in flux decline, whereas dynamic response of flux decline proved that increasing Jrt during operation is due to fouling. The influence of TMP on resistances showed that total hydraulic resistance and reversible fouling resistance are increased with increasing TMP, but intrinsic membrane resistance and irreversible fouling resistance did not change. Increasing the total hydraulic resistance with time resulted in increasing both reversible and irreversible fouling resistances. Increasing TMP or operation time had no significant effect on protein rejection, but only led to an increase about 1-4 percent. M3 ER -