" py SiRC": Machine Learning Combined with Molecular Fingerprints to Predict the Reaction Rate Constant of the Radical-Based Oxidation Processes of Aqueous Organic Contaminants

Environ Sci Technol. 2021 Sep 21;55(18):12437-12448. doi: 10.1021/acs.est.1c04326. Epub 2021 Sep 2.

Abstract

We developed a web application structured in a machine learning and molecular fingerprint algorithm for the automatic calculation of the reaction rate constant of the oxidative processes of organic pollutants by OH and SO4•- radicals in the aqueous phase-the pySiRC platform. The model development followed the OECD principles: internal and external validation, applicability domain, and mechanistic interpretation. Three machine learning algorithms combined with molecular fingerprints were evaluated, and all the models resulted in high goodness-of-fit for the training set with R2 > 0.931 for the OH radical and R2 > 0.916 for the SO4•- radical and good predictive capacity for the test set with Rext2 = Qext2 values in the range of 0.639-0.823 and 0.767-0.824 for the OH and SO4•- radicals. The model was interpreted using the SHAP (SHapley Additive exPlanations) method: the results showed that the model developed made the prediction based on a reasonable understanding of how electron-withdrawing and -donating groups interfere with the reactivity of the OH and SO4•- radicals. We hope that our models and web interface can stimulate and expand the application and interpretation of kinetic research on contaminants in water treatment units based on advanced oxidative technologies.

Keywords: apps and web applications; artificial intelligence; emerging contaminant degradation; kinetic parameters.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Hydroxyl Radical
  • Kinetics
  • Machine Learning
  • Oxidation-Reduction
  • Water
  • Water Pollutants, Chemical*
  • Water Purification*

Substances

  • Water Pollutants, Chemical
  • Water
  • Hydroxyl Radical