NOM介导下微塑料的光老化及典型增塑剂的释放与转化机制

光老化是微塑料在环境中重要的老化机制之一，并伴随着有害添加剂的释放，对微塑料的环境行为与生态风险产生重要影响。天然水体的化学成分可能会影响微塑料的光老化，然而目前缺乏深入与系统的研究。天然有机质（Natural Organic Matter，NOM）是自然水体中普遍存在的光学活性物质，光照后可能与微塑料相互作用并形成富含高浓度活性氧物种的疏水性“微反应器”，对微塑料的光老化及有害添加剂的释放与转化可能产生显著影响。因此，本项目以高活性微反应器为切入点，结合多种显微与表征手段、电子自旋共振波谱法、分子探针试验、在线电化学-质谱技术、固相萃取富集、气相色谱-质谱等手段，研究天然有机质对微塑料光老化的进程及典型增塑剂的释放与转化动力学的影响，并揭示天然有机质介导下微塑料光老化的微观机理及典型增塑剂的释放与转化机制，为深入理解自然水体中微塑料的环境行为与潜在风险提供新的思路。

Photo-aging, one of the important aging mechanisms of microplastics in the environment and often accompanied by the release of harmful additives, has an important impact on the environmental behavior and ecological risk of microplastics. The chemical components of natural water may affect the photo-aging process of microplastics. However, there is a lack of in-depth and systematic research on this subject. Natural organic matter (NOM) is a kind of optically active substance ubiquitously existed in natural water. When exposed to light, it may interact with microplastics and form hydrophobic microreactors with high concentrations of reactive oxygen species, which will have a significant impact on the photo-aging process of microplastics and the release and transformation of harmful additives. Therefore, this project intends to study the effects of natural organic matter on the photo-aging process of microplastics and the release and transformation kinetics of typical plasticizers by using a variety of microscopic and characterization methods, the electron spin resonance spectroscopy, molecular probe tests, the online electrochemical-mass spectrometry, solid-phase extraction and gas chromatography-mass spectrometry analysis. The involved microscopic mechanisms of photo-aging and the release and transformation of typical plasticizers will be revealed as well. The results from this project will provide us new insights into the environmental behavior and ecological risk of microplastics in natural water.