Ozone Catalysis Degradation of Sodium Acetate via Vacancy-Driven Radical Oxidation over Fe-Modified Fly Ash

Abstract

In order to realize the high value-added reuse of coal fly ash, a reusable Fe-modified fly ash catalyst was synthesized for ozone catalysis degradation of chemical oxygen demand (COD) in wastewater. Through enhancement of the pretreatment procedure and FeOx modification, the resulting fly ash with Fe modification demonstrated increased specific surface area and porosity. The presence of Fe loading significantly enhances the reactivity of surface oxidizing reactive species, particularly oxygen vacancy, leading to improved adsorption and activation properties towards ozone molecules. Sodium acetate is chosen as a probe for contaminants due to its status as a small organic substance that remains resistant to further direct oxidation by ozone. This makes it suitable for evaluating the catalyst’s effectiveness in degrading chemical oxygen demand (COD). The quantitative detection of free radicals revealed the generation of •O2− was nearly 10 times that of •OH and dominated the reaction. This study showcases the potential of fly ash, an industrial byproduct, to be utilized as a cost-effective and easily prepared catalyst with consistent physical and chemical characteristics.