A critical review of solid peroxides in environmental remediation and water purification: From properties to field applications

Due to the effective oxidation performance and slow oxygen release properties, solid peroxides including calcium peroxide (CaO2), magnesium peroxide (MgO2), and sodium percarbonate (Na2CO3·1.5H2O2) have gained increasing attention as alternative oxidants of hydrogen peroxide (H2O2). This review provides an overview of the recent progress of solid peroxides in environmental remediation and water purification based on the current literature. The physical and chemical properties of solid peroxides, as well as the O2 and H2O2 release properties, are outlined. A discussion of the latest modifications, that aim to improve the performance of solid peroxides in applications is also provided. Then, the mechanisms involved in the application, including chemical oxidation, bioremediation promotion, and physicochemical reaction are covered. Above all, the applications of solid peroxides across different water and soil mediums in laboratory studies and field applications are reviewed. In particular, this review focuses on the similarities and differences in the properties of the three solid peroxides, and the corresponding advantages and disadvantages in applications. Finally, the knowledge gaps, challenges, and new opportunities in this field are defined.