Sodium Percarbonate-Based Advanced Oxidation Processes for the Degradation of Emerging and Recalcitrant Contaminants Across Water, Soil, Sediment, and Sludge Matrices

The widespread release of emerging and recalcitrant pollutants into the environment necessitates robust removal technologies. Advanced oxidation processes (AOPs) are known for degrading such pollutants, and sodium percarbonate (SPC) emerges as an alternative to liquid H2O2, generating both non-selective hydroxyl (•OH) and carbonate (CO3•−) radicals that are selective toward electron-rich moieties through physical energy inputs (UV, ultrasound, and cavitation) or transition metal/composite catalysts. This review examines recent literature on SPC-based AOPs, organized by pollutant category across water, soil, sludge, and sewer environments. A recurring finding is that SPC’s performance, including which reactive oxygen species predominates and the extent of true carbon mineralization, depends strongly on the specific activation strategy, pollutant, and matrix. Beyond pollutant degradation, SPC supports environmental and resource sustainability through functional applications, including greenhouse and odour gas suppression (CH4, H2S) in sewer deposits, enhanced sludge dewatering, and volatile fatty acid recovery. However, claims regarding SPC’s sustainability should be qualified against energy demand, catalyst synthesis, residual metal leaching, and under-characterised transformation-product ecotoxicity. By consolidating these findings, this review clarifies SPC’s demonstrated potential and defines the research directions that will support its translation toward real-world remediation, including pilot-scale validation, techno-economic analysis, and long-term catalyst and by-product management.