Wu Nannan, Yu Haibin, Liu Zhenzhen, Di Shanshan, Zhao Huiyu, Wang Zhiwei, Wang Zunyao, Wang Xinquan, Qi Peipei
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China; State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China.
Water Res. 2025 Apr 1;273:123048. doi: 10.1016/j.watres.2024.123048. Epub 2024 Dec 27.
Tris(2-choroethyl) phosphate (TCEP) is commonly utilized as a flame retardant and plasticizer, which inevitably coexists with polystyrene microplastics (PS-MPs) in aquatic environments. In this work, the promoting effect of pristine and aged PS-MPs on the photodegradation of TCEP was observed, and the reaction mechanisms and environmental risks of PS-MPs enhancing TCEP photodegradation were clearly revealed. The aged PS-MPs presenting more significant enhancement was attributed to more generation of reactive oxygen species (ROS). The yield of •OH generated in the aged PS-MPs system was 21 times as high as that of pristine PS-MPs. Contributions of •OH, O and O to the degradation of TCEP induced by aged PS-MPs were 59.07 %, 34.98 % and 7.8 %, respectively. Possible degradation products of TCEP were identified, primarily formed through hydroxyl substitution, intramolecular cyclization and carboxylation. Density functional theory calculations demonstrated that •OH was more likely to attack the P atom of TCEP than the C atom. The low molecular derivatives containing oxygen group of PS-MPs reacted with •Cl/•OCHCl released by TCEP to generate interaction products. Toxicity evaluation of interaction products suggested some interaction products were more toxic than TCEP, indicating that these interaction products contributed to the underestimation of transformation risk of TCEP and coexisting PS-MPs. This study provides a novel insight into the fate and the ecological risks associated with the combined contamination of MPs and coexisting plastic additives.
磷酸三（2-氯乙基）酯（TCEP）通常用作阻燃剂和增塑剂，在水生环境中不可避免地会与聚苯乙烯微塑料（PS-MPs）共存。在本研究中，观察到原始态和老化态的PS-MPs对TCEP光降解的促进作用，并明确揭示了PS-MPs增强TCEP光降解的反应机制和环境风险。老化态PS-MPs表现出更显著的增强作用，这归因于更多活性氧物种（ROS）的产生。老化态PS-MPs体系中产生的•OH产率是原始态PS-MPs的21倍。老化态PS-MPs诱导的•OH、O和O对TCEP降解的贡献分别为59.07%、34.98%和7.8%。确定了TCEP可能的降解产物，主要通过羟基取代、分子内环化和羧化形成。密度泛函理论计算表明，•OH攻击TCEP的P原子比攻击C原子的可能性更大。PS-MPs含氧基的低分子衍生物与TCEP释放的•Cl/•OCHCl反应生成相互作用产物。相互作用产物的毒性评估表明，一些相互作用产物比TCEP毒性更大，这表明这些相互作用产物导致了对TCEP和共存PS-MPs转化风险的低估。本研究为微塑料与共存塑料添加剂联合污染的归宿和生态风险提供了新的见解。
