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DOI	10.1016/j.atmosenv.2021.118708
	Formation pathways and sources of size-segregated nitrate aerosols in a megacity identified by dual isotopes
	Zhu Y.; Zhou S.; Li H.; Luo L.; Wang F.; Bao Y.; Chen Y.
发表日期	2021
ISSN	1352-2310
卷号	264
英文摘要	Nitrate becomes a vital secondary component in atmospheric aerosols, especially in the urban areas with effective control of sulfur emissions. The elucidation of NO3− formation pathways and sources would be very helpful for accurately modeling and controlling the particle pollution. In this study, the dual isotopic compositions (δ15N and δ18O) of size-segregated NO3− aerosols were measured at an urban site of Shanghai in the winter of 2018 and the late summer of 2019. The formation mechanisms and sources of NO3− in five size-modes and different seasons were explored by combining analyses of dual isotopes, ion concentrations, air mass back trajectories and the Bayesian isotopic mixing model. Our results showed that the δ18O-NO3− values in summer (62.1 ± 12.8‰) were generally lower than those in winter (80.1 ± 9.9‰) with the lowest values in Aitken (sub–0.1 μm) and condensation modes (0.1–0.56 μm, 48.6 ± 9.8‰). This suggested that NO2 + ∙OH pathway probably played a significant role in the NO3− formation in summer (56.1 ± 4.8%) especially in Aitken and condensation modes, while N2O5 heterogeneous and NO3 + RH/RSC (hydrocarbons/reduced sulfur compounds) pathways could be critical in winter (55.0 ± 12.6% and 28.3 ± 15.2%, respectively). The isotopic fractionation may play a critical role in the size distribution of δ15N-NO3−. Based on the formation pathways of NO3− and calculated fractionation factors εN, the contribution of major NOx sources to NO3− aerosols in Shanghai was estimated. It was found that diesel engine exhaust contributed to the highest percentages (39.3% and 32.1%) of NO3− aerosols followed by gasoline engine exhaust (30.9%) and coal combustion (29.4%) in summer and winter, respectively. The contribution of coal combustion was almost doubled in winter compared to summer whereas soil emission decreased. Our results suggest that the impact of diesel engine exhaust on particle pollution in eastern Chinese megacities should be emphasized. © 2021 Elsevier Ltd
关键词	Dual isotopes Formation pathways Nitrate Size-segregated Sources
语种	英语
scopus关键词	Atmospheric aerosols; Coal combustion; Condensation; Diesel engines; Isotopes; Nitrogen oxides; Sulfur compounds; Urban growth; Diesel engine exhaust; Dual isotope; Formation pathways; Megacities; Nitrate aerosols; Particle pollution; Secondary components; Size-segregated; Source; Urban areas; Nitrates; acetylene; alkene; coal; gasoline; halogenated hydrocarbon; nitrate; nitrogen 15; oxygen 18; volatile organic compound; xylene; aerosol; air mass; coal combustion; diesel engine; isotopic analysis; isotopic composition; megacity; nitrate; sulfur emission; Article; biomass; boundary layer; city; combustion; concentration (parameter); controlled study; diesel engine; fractionation; hydrolysis; photochemistry; seasonal variation; secondary organic aerosol; summer; vapor pressure; winter; China; Shanghai
来源期刊	ATMOSPHERIC ENVIRONMENT
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/248229
作者单位	Shanghai Key Laboratory of Atmospheric Particle Pollution Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200438, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China; Institute of Eco-Chongming (IEC), Shanghai, 200062, China
推荐引用方式 GB/T 7714	Zhu Y.,Zhou S.,Li H.,et al. Formation pathways and sources of size-segregated nitrate aerosols in a megacity identified by dual isotopes[J],2021,264.
APA	Zhu Y..,Zhou S..,Li H..,Luo L..,Wang F..,...&Chen Y..(2021).Formation pathways and sources of size-segregated nitrate aerosols in a megacity identified by dual isotopes.ATMOSPHERIC ENVIRONMENT,264.
MLA	Zhu Y.,et al."Formation pathways and sources of size-segregated nitrate aerosols in a megacity identified by dual isotopes".ATMOSPHERIC ENVIRONMENT 264(2021).