Publication
Advanced Redox Technology Lab
Publication
Advanced Redox Technology Lab
Journal papers
Hydroxyl radical (•OH) generated during catalytic ozonation plays a central role in the degradation of ozone (O3)-resistant micropollutants (MPs). Accurate quantification of •OH exposure (∫[•OH]dt), which serves as a key indicator of oxidative capacity under defined conditions, is crucial for effective control of MPs in catalytic ozonation. However, direct in-field measurement of ∫[•OH]dt with a •OH probe compound is not practical. This study explores the application of machine learning (ML) models to predict ∫[•OH]dt in catalytic ozonation using readily available input variables. Using graphitic carbon nitride as a representative catalyst, catalytic ozonation experiments were conducted to quantify ∫[•OH]dt (the output variable) under varying operational (O3 dose, catalyst dose, contact time) and water quality (TOC, pH) parameters (input variables). Two ML models were constructed: Model-1 predicted only the final ∫[•OH]dt after full O3 consumption, whereas Model-2 included contact time as an added variable to estimate ∫[•OH]dt in a time-dependent manner. Both models demonstrated strong predictive performance. More importantly, Model-2 effectively captured the temporal profile of ∫[•OH]dt and yielded greater accuracy for final ∫[•OH]dt estimates by more comprehensively reflecting the effects of each variable. The model-predicted ∫[•OH]dt values were subsequently used for simulating MP degradation, which corresponded closely with experimental observations for multiple O3-resistant MPs. These results demonstrate that ∫[•OH]dt predicted from readily obtained parameters can provide a robust indicator for MP removal, and that ML-powered methods present a valuable framework for optimizing catalytic ozonation systems.