Design-Oriented Interpretation of Chlorophenol Oxidation Kinetics in Advanced Oxidation Processes via Interpretable Machine Learning


Kahraman E. N., CAN Z. S.

Ozone: Science and Engineering, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2026
  • Doi Number: 10.1080/01919512.2026.2663816
  • Journal Name: Ozone: Science and Engineering
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Compendex, Environment Index, INSPEC
  • Keywords: Abraham solute descriptors, advanced oxidation processes, chlorophenols, interpretable machine learning, oxidation kinetics, XGBoost
  • Marmara University Affiliated: Yes

Abstract

Oxidation rate constants are critical parameters for the design and optimization of advanced oxidation processes (AOPs) employed to remove persistent organic pollutants from water. In this study, an interpretable, design-oriented modeling framework is developed to predict pseudo-first-order oxidation rate constants expressed as log10(k) for chlorophenols under photo-Fenton, Fenton, and photoperoxidation conditions, while direct UV photolysis is considered separately as a non-radical photochemical treatment. Experimental operating parameters, including pH, temperature, oxidant dosage, iron concentration, and radiation intensity, were integrated with Abraham solute descriptors to capture both process-level and molecular-level influences on oxidation kinetics. An Extreme Gradient Boosting (XGBoost) model was trained and interpreted using SHapley Additive exPlanations (SHAP). Model performance was evaluated using nested grouped cross-validation, with folds constructed to ensure prediction on previously unseen chlorophenol compounds. The optimized model achieved strong in-sample performance (training R2 = 0.94 ± 0.10) and moderate generalization to unseen compounds (test R2 = 0.41 ± 0.50; RMSE = 0.54 ± 0.27 on log10(k)). Model interpretation revealed that oxidation kinetics are predominantly governed by operating conditions, while molecular descriptors related to polarizability and hydrogen bonding interactions modulate pollutant-specific reactivity. Overall, the proposed framework provides mechanistically interpretable insights that support rational AOP selection and operating-condition optimization.