Photoaging mechanism of microplastics:a perspective on the effect of dissolved organic matter in natural water  

作　　者：Ying Yu Xinna Liu Yong Liu Jia Liu Yang Li 

机构地区：[1]College of Arts and Sciences,Northeast Agricultural University,Harbin 150030,China [2]Key Laboratory of Water and Sediment Sciences of Ministry of Education,State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University,Beijing 100875,China [3]Institutional Center for Shared Technologies and Facilities,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing,100101 China [4]Institute of Analysis and Testing,Beijing Academy of Science and Technology,Beijing Center for Physical&Chemical Analysis,Beijing 100089,China

出　　处：《Frontiers of Environmental Science & Engineering》2023年第11期287-293,共7页环境科学与工程前沿（英文）

基　　金：supported by the Fund for National Key R&D Program of China(No.2021YFC3200401);the National Natural Science Foundation of China(Nos.52170024,21677015,22006031).

摘　　要：Plastic products widespread in natural water can be broken into smaller-sized microplastics(MPs,<5 mm)under light irradiation,thermal degradation and biodegradation,posing a serious threat to aquatic ecosystems and human health.This perspective concludes that MPs can generate reactive oxygen species(ROS)through initiation,propagation and termination steps,which can attack the polymer resulting in the photoaging and breakdown of C–C and C–H bonds under ultraviolet(UV)irradiation.Free radical generation and weathering degree of MPs depend on their physicochemical properties and environmental conditions.In general,UV irradiation and co-existed MPs can significantly accelerate MP photoaging.With plentiful chromophores carbonyl,carboxyl and benzene rings,Dissolved organic matter(DOM)mainly absorbs photons(300–500 nm)and generates hydrated electrons,^(3)DOM^(*) and ROS,which may affect MP photoaging.However,whether DOM may transfer the electron and energy to MPs under UV irradiation,affect ROS generation of MPs and their photoaging pathway are inadequately studied.More studies are needed to elucidate MP photoaging pathways and mechanisms,consider the influence of stabilization capacity,photosensitization and photoionization of DOM as well as their competitive light absorption with MPs,which provides valuable insights into the environmental behavior and ecological risk of MPs in natural water.

关 键 词：Microplastics PHOTOAGING Dissolved organic matter ROS generation 

分 类 号：O62[理学—有机化学]