Theoretical insights into the degradation mechanisms, kinetics and eco-toxicity of oxcarbazepine initiated by OH radicals in aqueous environments  

作　　者：Yanhui Sun Ming Li Mohammad Hassan Hadizadeh Lin Liu Fei Xu 

机构地区：[1]College of Environment and Safety Engineering,Qingdao University of Science and Technology,Qingdao 266042,China [2]Environment Research Institute,Shandong University,Qingdao 266237,China

出　　处：《Journal of Environmental Sciences》2023年第7期189-201,共13页环境科学学报（英文版）

基　　金：This work was supported by the Shandong Provincial Natural Science Foundation of China(No.ZR2021MB039);the National Natural Science Foundation of China(No.21607089);the Shandong Provincial Key Research and Development Program(Major Scientific and Technological Innovation Project)(No.2020CXGC011402).

摘　　要：As an anticonvulsant,oxcarbazepine(OXC)has attracted considerable attention for its potential threat to aquatic organisms.Density functional theory has been used to study the mechanisms and kinetics of OXC degradation initiated by OH radicals in aqueous environment.A total of fourteen OH-addition pathways were investigated,and the addition to the C8 position of the right benzene ringwas themost vulnerable pathway,resulting in the intermediate IM8.The H-abstraction reactions initiated by OH radicalswere also explored,where the extraction site of the methylene group(C14)on the seven-member carbon heterocyclic ring was found to be the optimal path.The calculations show that the total rate constant of OXC with OH radicals is 9.47×10^(9)(mol/L)^(−1)sec^(−1),and the half-life time is 7.32 s at 298 K with the[·OH]of 10^(−11) mol/L.Moreover,the branch ratio values revealed that OH-addition(89.58%)shows more advantageous than H-abstraction(10.42%).To further understand the potential eco-toxicity of OXC and its transformation products to aquatic organisms,acute toxicity and chronic toxicity were evaluated using ECOSAR software.The toxicity assessment revealed that most degradation products such as OXC-2OH,OXC-4OH,OXC-1O-1OOH,and OXC-1OH’are innoxious to fish and daphnia.Conversely,green algae are more sensitive to these compounds.This study can provide an extensive investigation into the degradation of OXC by OH radicals and enrich the understanding of the aquatic oxidation processes of pharmaceuticals and personal care products(PPCPs).

关 键 词：OXCARBAZEPINE OH radicals Degradation mechanisms Kinetic calculation Eco-toxicity evaluation 

分 类 号：X171.5[环境科学与工程—环境科学]