Analysis of the Membrane Fouling Mechanisms Involved in Clarified Grape Juice Ultrafiltration Using Statistical Tools

Abstract

Statistical tools were used to analyze membrane fouling occurring during ultrafiltration (UF) of clarified grape juice. Experimental flux data were correlated to dead-end and crossflow filtration models. The UF experiments were performed at 30 and 40 °C for an 8-kDa multitubular ceramic membrane and also at 30 °C for a 1-kDa membrane to determine the effect of pore size. ANOVA was used for the statistical analysis of fluxes. The modified Kolmorov-Smirnov and the Shapiro-Wilk tests were used to evaluate the normality of the residuals obtained from each model, thus allowing validation or rejection of initial adjustments given by a simple R-square statistical test. Using the standard error of the estimate and the mean absolute error it was possible to identify the best model for each case. Differences in the permeate flux and fouling mechanisms between both temperatures and pore size were discussed.

Studies of membrane fouling mechanisms involved in the micellar-enhanced ultrafiltration using blocking models

“…In this study, the fouling type is determined by Hermia blocking model 23 (Table 1). The estimation of K-constant associated with each of the models is calculated by nonlinear regression of the experimental data.…”

“…In Hermia's blocking model, a K-value can be used to estimate the degree of membrane pore blocking 23 . As shown in Table 3, for internal pore blocking, intermediate pore blocking and cake formation model, the increased K-values have the following order: CG 12 < CG 16 < CG 12 +Brij35 < CG 16 +Brij35, which indicates that the thickness of cake layer occurring on membrane surface presents the same sequence as flux behavior in section 4.1.…”

“…Hwang et al 20 claimed that various membranes had different blocking types, e.g., standard blocking occurred in MF-Millipore membrane, while a complete blocking existed in an Isopore membrane and a Durapore membrane presented cases of intermediate blocking. Recently, some studies 23,24 used a blocking model to explain the fouling mechanism of cross-flow filtration. Ho et al 21 put forward a new mathematical model to calculate the thickness of cake layer formed on the membrane surface in protein filtration.…”

Investigation of membrane fouling mechanisms using blocking models in the case of shear-enhanced ultrafiltration

“…Shear-enhanced membrane filtration, which outweighs the traditional cross flow membrane filtration process in stable permeate flux, excellent rejection and low concentration polarization [1], has been widely applied in wastewater treatment [2], chemical engineering [3], medical engineering [4] and food engineering [5] as well as biotechnological separations [6]. Shear-enhanced membrane filtration currently suffers from high energy consumption, membrane fouling and high equipment cost, etc.…”

“…Another smooth transition model, which considers the change from pore blocking fouling to cake filtration resistance with time, was introduced to simplify the cumbersome process that use different models to explain the entire filtration process [21]. Recently, some studies [5,22] devoted to cross-flow filtration and could help to explain the fouling mechanism of cross-flow filtration. Because the amount of solutes contained in the convective flow along membrane surface is larger than that removed by cross flow action, this is similar to dead-end filtration.…”