Highly Oxidized Molecules Make a Significant Contribution to Enhanced Aromatic-Derived Secondary Organic Aerosol under a Humid Environment  

作　　者：Zhaomin YANG Kun LI Lin DU 

机构地区：[1]Environment Research Institute,Shandong University,Qingdao 266237,China

出　　处：《Advances in Atmospheric Sciences》2025年第4期641-652,共12页大气科学进展(英文版)

基　　金：supported by the National Key Research and Development Program of China (Grant No. 2023YFC3706203);the National Natural Science Foundation of China (Grant Nos. 91644214, 22361162668, and 22406109);the China Postdoctoral Science Foundation (Grant No. 2024M751797);Shandong Postdoctoral Science Foundation (SDCX-ZG-202400178)

摘　　要：Enhanced mass concentrations of aromatic-derived secondary organic aerosol(SOA)are frequently observed during humid-haze events.However,the influencing mechanism of relative humidity(RH)in aromatic-derived SOA formation remains incompletely understood.Here,the RH dependence of SOA formation in the presence of NOx was explored by a series of chamber experiments for toluene(TOL)and 1,3,5-trimethylbenzene(TMB)photooxidation.The yield of TOL SOA and TMB SOA increased by 221%and 52%with increasing RH from~8%to~70%,respectively.Analytical results from a high-resolution mass spectrometer showed that SOA constituents with high oxygen content(O/C>0.6)were more abundant in SOA formed in the~70%RH experiment.The elevated yields and O/C of SOA could be attributed to the promoted formation and particle-phase diffusivity of highly oxidized molecules.In addition,in comparison with TMB,TOL could produce more unsaturated aldehydes,which are oxidized into carboxylic acids with high O/C,leading to a more sensitive response of TOL SOA formation to the change in RH.Our work provides mechanistic insights into RH roles in aromatic SOA formation and is helpful for a better understanding of humid-haze events.

关 键 词：secondary organic aerosol aromatic hydrocarbons highly oxidized molecules relative humidity 

分 类 号：X513[环境科学与工程—环境工程]