Chapter 8: Sulfate Radical-based Advanced Oxidation Processes for Water and Wastewater Disinfection

Sulfate radical (SO₄˙⁻)-based advanced oxidation processes (AOPs) have emerged as promising technologies for inactivation of pathogenic microorganisms in water and wastewater, due to the high oxidation potential and selectivity of SO₄˙⁻ towards different microorganisms, and the negligible formation of undesired byproducts by using these processes. This book chapter provides an overview of the kinetic responses of various pathogenic/indicator microorganisms toward different SO₄˙⁻ based AOPs (e.g., metal-assisted, light-assisted, and piezo-catalytic ones) and the mechanisms responsible for the inactivation (e.g., via membrane destruction, enzyme and genome damage, and affecting repair that doesn't need light). The effects of solution chemistry (e.g., pH, temperature, and various water matrices) on the disinfection efficacies have also been reviewed and discussed. The formation of undesired byproducts in the SO₄˙⁻ based AOPs is also reviewed and discussed. Key points from the review are summarized in the conclusive remarks. Knowledge gaps, research needs, and design requirements for the engineering applications of these processes in real-world practice are proposed as future perspectives.