Interpretable Machine Learning Models Delivering a New Perspective for the Reaction Mechanism between Organic Pollutants and Oxidative Radicals.

Journal: Environmental science & technology
PMID:

Abstract

Machine learning (ML) is expected to bring new insights into the impact of organic structures on the reaction mechanisms in reactive oxygen species oxidation. However, understanding the underlying chemical mechanisms still faces challenges due to the limited interpretability of the ML models. In this study, interpretable ML models were established to predict the second-order rate constants between hydroxyl radicals (OH) and organics (). It was found that the energy of the highest occupied molecular orbital (), the number of aromatic rings (), and the number of carbon atoms of organics () have important impacts on . The positive correlation between and can be explained by the regularity of electrophilic reaction, while the relationship between and and seems to be related with reactive sites. Furthermore, a rapid judgment method for reaction mechanism was developed based on an unsupervised learning approach which automatically divided organics into three clusters. Additionally, this methodology was applied to the reaction between organics and sulfate radicals. This study offers a rational model for predicting reaction mechanisms and provides more insights into the impact of organic structures on the reaction mechanism from the perspective of big data.

Authors

  • Yiqiu Wu
    Chemistry & Chemical Engineering Data Center, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
  • Zhixiang Wang
    Department of Ultrasound, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
  • Guangfei Yu
    MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
  • Yuehong Zhao
    Chemistry & Chemical Engineering Data Center, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
  • Chuncheng Chen
    Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
  • Yongbing Xie
    Chemistry & Chemical Engineering Data Center, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
  • Hongbin Cao
    Department of Radiation Oncology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.