Driving force to promote transport by way of the membrane. When the applied stress overcomes the electrical repulsion, proteins method the membrane surface and may perhaps gelify on it, in the event the local concentration inside the boundary layer reaches the gelling circumstances, developing membrane fouling. So as to limit fouling phenomena for the duration of ultrafiltration approach in concentration mode, the crucial pressure in the two selected pH values and at protein concentration from 0.5 to 2 g -1 was investigated. The essential stress was 0.two bar when the initial protein concentration was 0.five or 1 g -1 , and it decreased down to 0.1 bar when the initial concentration was increased up to 2 g -1 (Table two). Even so, in all of the analyzed cases, around the basis of hydraulic CYM-5478 site resistance measurements (Table two), no important irreversible fouling was triggered.Table two. Essential pressure, hydraulic resistance of membrane, and fouling components obtained by ultrafiltration of binary protein mixture at unique initial concentration and pH. Protein Mixture (g -1 ) Important Pressure (bar) 0.two 0.2 0.two 0.2 0.1 0.1 Vital Flux (L -1 -2 ) 68 () 64 () 70 () 68 () 35 () 25 () Rtot (m-1 ) 1.00 1012 (.00 1010 ) 1.24 1012 (.44 1010 ) 1.18 1012 (.44 1010 ) 1.68 1012 (.01 1010 ) 1.16 1012 (.96 1010 ) 1.68 1012 (.40 1010 ) Rm (m-1 ) 9.67 1011 (.80 1010 ) 1.01 1012 (.00 1010 ) 8.29 1011 (.80 1010 ) eight.7 1011 (.22 1010 ) 9.20 1011 (.60 1010 ) 9.73 1011 (.84 1010 ) Rfrev (m-1 ) three.34 1010 (.34 109 ) 1.64 1011 (.40 1010 ) three.50 1011 (.45 1010 ) eight.ten 1011 (.86 1010 ) 2.15 1011 (.60 1010 ) six.79 1011 (.75 1010 ) Rfirr (m-1 ) 0 two.20 1010 0 0 2.56 1010 2.62 1010 pH3.0 0.5 three.four 3 1 3.4 three.0 two 3.Rm = hydraulic resistance because of the membrane; Rtot = hydraulic resistance resulting from membrane and fouling; Rfirr = hydraulic resistance as a consequence of irreversible fouling; Rfrev = hydraulic resistance because of reversible fouling. It really is worth underlining that the Rfirr is within the error array of Rm and Rtot ; this confirms its negligible contribution to Rtot .Appl. Sci. 2021, 11,eight of3.three. Binary Protein Mixture Ultrafiltration at pH three in Concentration Mode As currently pointed out inside the Components and Methods section, the ultrafiltration of binary protein mixtures was carried out in concentration mode. A continuous flux as a function of time was observed when the ultrafiltration approach was carried out applying initial protein concentrations of 0.five or two g -1 (Figure three). In particular, working with an initial protein concentration of 0.5 g -1 and applying a TMP of 0.2 bar, a steady-state flux of 68 () L -1 -2 was obtained, though working with an initial protein concentration of 2 g -1 and applying a TMP of 0.1 bar, a steady-state flux of 30 () L -1 -2 was obtained. Appl. Sci. 2021, 11, x FOR PEER Critique equivalent flux obtained operating in concentration mode (Figure three) or at constant feed eight of 13 The volume (Table two) can be a additional confirmation that no significant fouling is observed, because just reversible fouling is obtained, which might be easily removed by washing actions. The TMP values 10-9) mPa-1 -1 was also to the outcomes of your criticalUF with protein Furthermore, in (.68 have been chosen Sapienic acid Bacterial according fully restored after stress study. solutions (6.65 9 this series of10-9) mPa-1 -1). In initial pure water permeance (6.70 10-8 (.68 10-as 10-8 (.52 experiments, the Figure 4, the electrophoretic profile of samples analyzed ) mPa-1 -1 of ultrafiltration time had been reported UF with with all the options (six.65 10-8 a function was also totally re.
