Advancements in heterogeneous activation of persulfates: Exploring mechanisms, challenges in organic wastewater treatment, and innovative solutions

This review provides a focused and comprehensive overview of the cutting-edge advancements in advanced oxidation processes employing heterogeneous persulfate activation technologies (PS-AOPs), which can serve as effective tools for tackling emerging organic pollutants. This review focuses on the evolution of PS activation mechanisms and the possible challenges in system application. The review delineates traditional radical mechanisms and elucidates non-radical pathways, such as singlet oxygen, high-valent metal-oxo species, electron transfer, and direct oxidation transfer process. By extensively using empirical data, this review also summarizes the reasons behind the emergence of different oxidation mechanisms and offers potential methods to modulate reaction pathways. It also explores the ecological impacts of the system and suggests prospective strategies for improving by-product management to optimize pollutant removal and ecological sustainability. This review can reveal the untapped potential and future directions of heterogeneous PS-AOPs, making an essential contribution to environmental remediation.