In this work, the hydroxylation mechanisms and kinetics of some emerging disinfection byproducts (DBPs) have been systematically investigated through theoretical calculation methods. Five chlorophenols and eleven halogenated pyridinols were chosen as the model compounds to study their pH-dependent reaction laws in UV/H₂O₂ system. For the reactions of HO^• with 37 different dissociation forms, radical adduct formation (RAF) was the main reaction pathway, and the reactivity decreased with the increase of halogenation degree. The k_app values (at 298 K) increased with the increase of pH from 0 to 10, and decreased with the increase of pH from 10 to 14. Compared with phenol, the larger the chlorination degree in chlorophenols was, the stronger the pH sensitivity of the k_app values; compared with chlorophenols, the pH sensitivity in halogenated pyridinols was further enhanced. As the pH increased from 2 to 10.5, the degradation efficiency increased at first and then decreased. With the increase of halogenation degree, the degradation efficiency range increased, the pH sensitivity increased, the optimal degradation efficiency slightly increased, and the optimal degradation pH value decreased. The ecotoxicity and bioaccumulation of most hydroxylated products were lower than their parental compounds. These findings provided meaningful insights into the strong pH-dependent hydroxylation of emerging DBPs on molecular level.

在这项工作中，通过理论计算方法系统地研究了一些新出现的消毒副产物 (DBP) 的羟基化机制和动力学。_{选择五种氯酚和十一种卤代吡啶酚作为模型化合物，研究它们在 UV/H 2} O ₂体系中的 pH 依赖性反应规律。^{对于具有37种不同解离形式的HO •}反应，自由基加合物形成（RAF）是主要反应途径，反应活性随着卤化度的增加而降低。k_应用程序值（在298 K）随着pH从0增加到10而增加，随着pH从10增加到14而减少。与苯酚相比，氯酚的氯化度越大，k的pH敏感性越强_应用程序价值观；与氯酚相比，卤代吡啶酚的pH敏感性进一步增强。随着pH从2增加到10.5，降解效率先增加后降低。随着卤化度的增加，降解效率范围增加，pH敏感性增加，最佳降解效率略有增加，最佳降解pH值降低。大多数羟基化产物的生态毒性和生物蓄积性低于其母体化合物。这些发现为新兴 DBP 在分子水平上的强 pH 依赖性羟基化提供了有意义的见解。