Chapter 7: Persulfate-based Advanced Oxidation Processes in Environmental Remediation: Theoretical Chemistry Study

Persulfate-based advanced oxidation processes (P-AOPs) utilizing strong reactive oxygen species (SO₄˙⁻, ˙OH, or ¹O₂) from persulfate activation, could be used to degrade highly resistant and toxic organic contaminants. In order to investigate the performance and mechanism of persulfate activation for pollutant degradation on P-AOPs, various techniques have been utilized in experiments. However, it is challenging to elucidate the inner mechanism and explore the essential reasons at the electronic and atomic levels. Theoretical chemistry studies are an effective supplement to experimental results to manifest the reaction mechanism. In addition, they have an excellent ability to systematically predict the experimental results, and guide the design of catalysts. Currently, there are no systemic and comprehensive evaluation criteria on theoretical chemistry studies to guide and estimate the performance and mechanism of P-AOPs for environmental remediation. In this chapter, the evaluation criteria from the view of theoretical chemistry are summarized systematically in the following three areas: (1) the persulfate activation process; (2) pollutant degradation process; and (3) influencing factors. The criteria are guidable, comprehensive, and reasonable to evaluate the performance and understand the mechanism of P-AOPs at the electronic and atomic levels. This chapter has practical significance for the development and application of theoretical chemistry in environmental remediation.