Fig. 1: Comparison between a decoupled oxidation process (DOP) and a conventional advanced oxidation process (AOP).

a Schematically shows the DOP method which spatially separates oxidant reduction and organic contaminant oxidation, preventing direct contact between harmful oxidants and contaminated water. b Illustrates conventional AOPs, where oxidant chemicals are directly added to contaminated water, potentially posing hazards to the environment and leading to the formation of secondary pollutants.