Abstract

PITTOL VERA, José A; LLATAS, Isabel  and  DER JANI-BAYEH, Sylvana. TATISTICAL DIFFERENCES AMONG PORE DISTRIBUTION MODELS OBTAINED FROM REJECTION PROFILE OF ULTRAFITRATION MEMBRANES. Rev. Fac. Ing. UCV [online]. 2011, vol.26, n.1, pp.129-141. ISSN 0798-4065.

The effective pore size distribution of ultrafiltration membranes’ is obtained from the experimental rejection profile of different types of membranes and solutes. For this, the hydrodynamic transport model is assumed and different standards probability density functions are compared to describe the effective pore size distribution. The chosen probabilistic models are the gamma, log-normal and Weibull, because they are skewed to the right. The robust Levenberg-Marquardt algorithm for non-linear regression as implemented in Matlab® lsqcurvefit subroutine is used to provide the optimized parameters. The 95% confidence intervals for the optimized parameters are obtained from nlparci subroutine in Matlab®. The analysis of variance (ANOVA) is used to test the effects of the probability distribution model in the prediction of the central moments, the average sieving coefficient and the average water flux. With statistical significant differences between 5 and 10%, the two-way and one-way (ANOVA) analysis, indicated that the chosen probabilistic model introduced a significant difference in the predictions of the effective average pore size, and the average sieving coefficient

Keywords : Ultrafiltration; Rejection profile; Effective pores size distribution; Average effective pore size; Average sieving coefficients.