Optimization of Chromium (Vi) Removal by Donnan Dialysis

Abstract

The removal of chromium (VI) from aqueous solutions by Donnan dialysis has been investigated in this paper. In this process, two anion-exchange membranes (AEMs) were used: Selemion® AMV and Neosepta® AFN. The amount of chromium (VI) removed was determined in terms of the following parameters: initial concentration of chromium (VI), type of anion-exchange membrane, concentration of counter-ion and magnetic stirring rate. A 2^4 full factorial design analysis was performed to screen the parameters affecting the Cr (VI) removal efficiency. Using the experimental re- sults, a linear mathematical model representing the influence of the different parameters as well as their interactions was obtained. Analysis of the variance (ANOVA), the F-test and the student’s test shows that the type of anion-exchange membrane is the most significant parameter affecting the chromium (VI) removal. The statistical analysis of the ex- perimental data assumes it to be a normal distribution