Catalytic ozonation of high-salinity wastewater using salt-resistant catalyst Fe-Bi@γ-Al2O3

Abstract

In this study, a salt-tolerant Fe-Bi@γ-Al2O3 catalyst with stable structure and excellent catalytic performance was prepared with an impregnation method by using γ-Al2O3 as the carrier. The effects of calcination temperature and calcination time on the catalytic activity of the Fe-Bi@γ-Al2O3 catalyst were evaluated. The catalyst was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, BET, X-ray diffraction, and X-ray fluorescence spectrometry to analyze the relationship between the catalyst's apparent morphology, structural characteristics, and catalytic activity. The optimal working conditions and organic degradation mechanism of Fe-Bi@γ-Al2O3 catalytic ozonation of a high-salinity organic wastewater system were studied. The active components Fe and Bi were successfully loaded on the surface of γ-Al2O3 in the form of Fe2O3 and Bi2O3 crystals. Under the working conditions of ozone aeration rate of 0.2 L/min, catalyst filling rate of 10 %, and pH = 11, the removal rate of COD in high-salinity organic wastewater was 83.9 %. The degradation mechanism of organic matter in wastewater was analyzed using ultraviolet absorption peak and three-dimensional fluorescence spectrum. Kinetic analysis of the COD removal rate of high-salinity organic wastewater under optimal working conditions was carried out. A 3E evaluation model of Fe-Bi@γ-Al2O3 catalyst for ozonation treatment of high-salinity organic wastewater was established to realize overall evaluation of the process performance.