Box-Behnken design for optimization of iron removal by hybrid oxidation-microfiltration process using ceramic membrane

This work reports the preparation and application of a microfiltration membrane based on kaolin. The membrane is characterized using various techniques such as XRD, FESEM, porosity, pure water permeation, and chemical stability tests. The fabricated membrane with a pore size of 1.66 mu m, porosity of 45.46%, and pure water permeability of 1.8 x 10(-8) (m(3) m(-2) s(-1) kPa(-1)) was utilized for studying iron removal from an aqueous solution by hybrid oxidation-microfiltration process. Response surface methodology (RSM) via Box-Behnken design (BBD) was used to study the effect of different input parameters (applied pressure, oxidant dosage, and initial concentration of iron) on permeate flux and iron removal. The experimental data were analysed using a model based on a second-order polynomial, which was then statistically confirmed. Analysis of variance (ANOVA) was used to develop and test the quadratic models between each response and the independent variables. The p value and F-values of the models developed for both the responses indicated the developed models were highly significant. The optimum conditions were found to be at an initial iron concentration of 49.95 mg L-1, an oxidant dose of 22.38 mg L-1, and applied pressure of 3.05 bar at which the permeate flux and rejection reported values of 1.32 x 10(-6) m(3) m(-2) s(-1) and 83.05%, respectively. These results agreed quite well with the experimental values. Based on these results the optimization of the microfiltration process using BBD was reliable in predicting the performance within the limits of the input parameters employed.