Optimizing Decolorization Efficiency of Methylene Blue by Photo-Fenton Process over Fe-Diatomite using Central Composite Design

Abstract

The methylene blue was degraded by photo-fenton over Fe-diatomite prepared by dry impregnation method. The characterizations of catalyst were studied by XRD, XRF and BET surface area. The photo-fenton reaction conditions were studied as parameters of the H2O2 concentration, the amount of Fe-diatomite, the initial concentration of methylene blue and the initial pH of solution, which were designed by central composite design (CCD) based on response surface methodology (RSM) to accomplish the optimal condition. The results showed that the optimum condition was at the initial H2O2 concentration of 116 mg/L, the Fe-diatomite of 1 g/L, the initial MB concentration of 200 mg/L and the pH of 5.8. It could predict the decolorization value of 100% and reduce the total organic carbon (TOC) to 72.3%. Finally, the validation was tested in 5 runs at the optimization about 99.2 ± 0.2% which implied that the regression model is in a good agreement.