Catalytic Wet Peroxide Oxidation of Dye Wastewater over Fe-Zr-Al/Mt Catalysts with High Activity and Stability

Abstract

The construction of a catalyst with high activity and stability is crucial for wastewater treatment. In this study, Fe-Zr-Al/pillared montmorillonite (Fe-Zr-Al/Mt) catalysts were successfully prepared by the conventional (C) ion exchange method and the microwave-assisted (MW-assisted) method with iron as an active component and montmorillonite as a carrier. X-ray diffraction, scanning electron microscope, Brunauer-Emmett-Teller, and Fourier transform infrared spectroscopy results were used to analyze the micromorphology of the catalyst and the existing form of active components. After comparing the basic fuchsin degradation rate and chemical oxygen demand (COD) removal rate of two prepared catalysts, the MW-assisted method was selected for subsequent studies. The influence of operating parameters, including initial pH, catalyst dosage, and reaction temperature, was optimized in the catalytic wet peroxide oxidation (CWPO) process for degradation of basic fuchsin. The results showed that under the optimal experimental conditions, about 99.23% of basic fuchsin and 81.48% of COD were degraded within 180 min, respectively. In addition, Fe-Zr-Al/Mt(MW) catalyst exhibited good stability and reusability. The catalytic activity decreased slightly after five consecutive runs, and the active component Fe leaching was only 0.0547 mg/L. The CWPO reaction mechanism on basic fuchsin degradation was proposed.