Inactivation of pathogenic microorganisms by sulfate radical: Present and future

Abstract

In recent years, inactivation of pathogenic microorganisms by sulfate radical anion (SO4·-) has attracted increasing attention due to growing demands to control harmful disinfection byproducts and update water treatment systems for efficient microbial control. This critical review focuses on the basic principles and current research status of SO4·--based inactivation technology, and for comparison includes OH-based inactivation of microorganisms. After a brief review of basic mechanisms of radical reactions with biomolecules, the inactivation kinetics and mechanisms by SO4·- in various activation systems are summarized and discussed. We demonstrated that SO4·- oxidatively damages the cell membrane/wall, proteins, and genetic materials (i.e., DNA and RNA), resulting in the inactivation of the microorganisms. Finally, existing problems, challenges, and possible solutions in engineering applications, and future research directions are discussed.