摘要
硝酸钠(NaNO_(3))是常见的大气无机细颗粒,它能够影响二次有机气溶胶(SOA)硝基芳香化合物(NACs)组分的形成和光学性质.本文利用烟雾腔系统研究NaNO_(3)细颗粒存在下苯乙烯光氧化产生SOA的大气化学过程,利用在线和离线仪器表征SOA的NACs组分和光学参数.实验结果显示,NaNO_(3)细颗粒可促进NACs组分的产生和SOA的形成.结合在线质谱测量和离线光谱验证,测得硝基羟基苯甲醛、硝基羟基苯甲酸、硝基乙烯基苯酚、二硝基羟基苯甲醛、二硝基羟基苯甲酸和二硝基乙烯基苯酚等NACs组分是NaNO_(3)细颗粒存在时SOA的主要组分.苯乙烯光氧化产生气相芳香环保留产物在NaNO_(3)细颗粒表面凝结并反应形成硝基酚、二硝基酚等吸光能力强的NACs组分,导致SOA在200~600 nm范围内的平均质量吸收系数(<MAC>)显著增加,并随NaNO_(3)细颗粒浓度的增大而逐渐增加.这为沿海城市NaNO_(3)细颗粒存在背景下,大气SOA颗粒NACs组分的来源指认和吸光特性研究提供了实验依据.
Sodium nitrate(NaNO_(3))is common atmospheric inorganic fine particles,which can affect the formation of nitroaromatic compounds(NACs)components and optical properties of secondary organic aerosol(SOA).The atmospheric chemical process of photooxidation for styrene to generate SOA in presence of NaNO_(3) fine particles was investigated using smog chamber in this study.The NACs components and optical parameters of SOA were characterized by on-line and off-line instruments.Experimental results demonstrated that NaNO_(3) fine particles promote the generation of NACs components and formation of SOA.Combined with on-line mass spectrometry measurement and off-line spectral verification,it was determined that nitro-hydroxybenzaldehyde,nitro-hydroxybenzoic acid,nitro-vinylphenol,dinitro-hydroxybenzaldehyde dinitro-hydroxybenzoic acid and dinitrovinylphenol were the main components of SOA in presence of NaNO_(3) fine particles.Gaseous aromatic ring retaining products formed from photooxidation of styrene condense on the surface of NaNO_(3) fine particles and react to generate nitro-phenols,dinitro-phenols and other NACs compounds with strong light absorption ability,resulting in a significant increase in averaged mass absorption coefficient(<MAC>)of SOA particles in 200~600 nm,and gradually increased with increasing concentration for NaNO_(3) fine particles.These results provide the experimental basis for the study of source identification and light absorption characteristics of NACs components in atmospheric SOA in presence of NaNO_(3) fine particles in coastal cities.
作者
池理盛
黄明强
朱敏聪
曾志威
赵卫雄
胡长进
顾学军
张为俊
CHI Lisheng;HUANG Mingqiang;ZHU Mincong;ZENG Zhiwei;ZHAO Weixiong;HU Changjin;GU Xuejun;ZHANG Weijun(Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology,College of Chemistry&Chemical Engineering and Environment,Minnan Normal University,Zhangzhou 363000;Laboratory of Atmospheric Physico-Chemistry,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031)
出处
《环境科学学报》
北大核心
2025年第12期76-87,共12页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.42275136)
福建省自然科学基金(No.2025J01972,2021J01987)。
关键词
硝酸钠
硝基芳香化合物
苯乙烯
二次有机气溶胶
光学性质
sodium nitrate
nitroaromatic compounds
styrene
secondary organic aerosol
optical property
