Abstract: Heterogeneous catalytic ozonation technology is a new ozone oxidation method and can degrade organic compounds that cannot be oxidized or degraded by ozone alone at room temperature and normal pressure. A SnO2 catalyst was prepared by the precipitation method and used in decolorization of molasses fermentation wastewater through ozonation. Effects of precipitants and calcination temperature on the catalytic ozonation activity of SnO2 were studied byX-raydiffraction, infrared spectroscopy (IR), and thermal analysis (TG-DSC). The results showed that the SnO2 catalyst exhibited considerably high catalytic activity for the catalytic ozonation decolorization of molasses fermentation wastewater. The decolorization rate of the wastewater was enhanced from 43.04% (using ozone oxidation alone) to 60.24%. The activity of the SnO2 catalyst was significantly affected by the precipitants. SnO2 prepared using ammonia as the precipitant showed higher degree of dehydroxylation and higher catalytic activity than those prepared using NaOH and Na2CO3 precipitants. The optimal calcination temperature of SnO2 was 723 K. The IR spectra of adsorbed pyridine showed that there were Lewis acid sites on the surface of the SnO2 catalyst. The IR spectra of O3 adsorbed on SnO2 showed that the terminal O atom of O3 was bonded to the surface hydroxyl group or a Lewis acid site to form a more active oxygen species that can oxidize and degrade the wastewater.

Key words: tin oxide, catalytic ozonation, molasses fermentation wastewater