Distinctive Sources Govern Organic Aerosol Fractions with Different Degrees of Oxygenation in the Urban Atmosphere

2021 ◽  
Author(s):  
Ruichen Zhou ◽  
Qingcai Chen ◽  
Jing Chen ◽  
Lujie Ren ◽  
Yange Deng ◽  
...  
Keyword(s):  
Organic Aerosol ◽  
Urban Atmosphere

Heterogeneous conversion of nitric acid to nitrous acid on the surface of primary organic aerosol in an urban atmosphere

2010 ◽  
Vol 44 (33) ◽  
pp. 4081-4089 ◽  
Author(s):  
Luke D. Ziemba ◽  
Jack E. Dibb ◽  
Robert J. Griffin ◽  
Casey H. Anderson ◽  
Sallie I. Whitlow ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Nitrous Acid ◽  
Organic Aerosol ◽  
Urban Atmosphere

Characteristics of PM2.5 aerosol particles during a heat wave in an urban atmosphere in southwest Germany

2020 ◽  
Author(s):  
Junwei Song ◽  
Linyu Gao ◽  
Harald Saathoff
Keyword(s):  
Black Carbon ◽  
Heat Wave ◽  
Mass Spectrometer ◽  
Heat Waves ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Ionization Mass ◽  
Aerosol Compositions ◽  
Southwest Germany

<p>Aerosol particles have significant impacts on climate, air quality, and human health. Their characteristics are especially important in urban atmospheres during heat waves. Therefore, we conducted a 4-week measurement campaign at an urban kerbside in the city of Karlsruhe in southwest Germany during a heat wave period in July 2019. A high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed in the container to measure non-refractory aerosol compositions of PM<sub>2.5</sub> online. Filter samples were also collected during the campaign, and characterized for oxygenated organic molecular compounds using a chemical ionization mass spectrometer (FIGAERO-CIMS). In addition, a small box with low cost particle sensors and meteorological sensors (solar radiation, temperature, and humidity) was used for spatial resolved measurements employing a bicycle. During our measurement, the total organics, sulfate, nitrate, ammonium, chloride and black carbon contributed on average 58.9%, 17.3%, 5.9%, 5.5%, 0.2% and 12.3% to the particle mass comprising non-refractory components plus black carbon. Positive matrix factorization (PMF) analysis for the AMS organic aerosol (OA) data resolved three factors including hydrocarbon-like OA (HOA), semi-volatile oxygenated OA (SV-OOA) and low-volatility oxygenated OA (LV-OOA). Meteorological effects on aerosol compositions were investigated. Low wind speeds during the whole campaign correspond to major contributions from local emissions. During heat waves, high temperature and low humidity suppressed the formation of nitrate, but facilitated the formation of sulfate and organics. In particular, SV-OOA and LV-OOA showed positive correlations with temperature. The ratios of LV-OOA to SV-OOA strongly correlated with temperature and odd oxygen (O<sub>x</sub> = O<sub>3</sub> + NO<sub>2</sub>), suggesting fast photochemical transformation of SV-OOA to LV-OOA during heat waves. Furthermore, the relationships between organic aerosol factors and typical organic markers were investigated to study the relative influences of biogenic and anthropogenic emissions on OA formation. Besides, bicycle measurements point to important hot spots of particle pollution. This contribution will discuss the interaction of urban air pollution and heat islands.</p>

scholarly journals Influence of Ammonium Sulfate Seed Particle on Optics and Compositions of Toluene Derived Organic Aerosol in Photochemistry

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 961
Author(s):  
Tingting Lu ◽  
Mingqiang Huang ◽  
Weixiong Zhao ◽  
Changjin Hu ◽  
Xuejun Gu ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Light Absorption ◽  
Radiative Forcing ◽  
Fine Particles ◽  
Complex Refractive Index ◽  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Seed Particle ◽  
Optical Parameters ◽  
High Concentration

Aromatic secondary organic aerosol (SOA) particles are known to contribute to radiative forcing and light absorption of atmosphere. However, the complex refractive index (CRI), single-scattering albedo (SSA) and other optical parameters of aromatic SOA are not well understood. SOA generated from photooxidation of toluene with a variety concentration of ammonium sulfate ((NH4)2SO4) seed particles in a smog chamber were investigated in the current study. The real part CRI of toluene SOA without seeds derived and based on aerosol albedometer measurements is 1.486 ± 0.002 at λ = 470 nm, showing a good agreement with available experimental data, and its SSA was measured to be 0.92 ± 0.02 at λ = 470 nm, indicating that the SOA particles without seeds have strong scattering ability. The SSA of SOA formed in the presence of 300 μg/m3 (NH4)2SO4 seed was 0.81 ± 0.02 at λ = 470 nm, less than the SSA of SOA without seed. SSA of SOA decreased, while the imaginary part of CRI (k) of SOA increased with increasing concentration of (NH4)2SO4 seed, demonstrating that the adsorption capacity of SOA formed in the presence of (NH4)2SO4 seed is enhanced. Different from the carboxyl compounds measured in the SOA without seed, imidazoles with strong chromophores of C=N that are responsible for the light absorption were detected as the principal constituents of SOA formed in the presence of (NH4)2SO4 seed. These would provide valuable information for discussing the optics and components of aromatic SOA in the urban atmosphere containing a high concentration of (NH4)2SO4 fine particles.

A large impact of cooking organic aerosol (COA) on particle hygroscopicity and CCN activity in urban atmosphere

2021 ◽  
Author(s):  
Jieyao Liu ◽  
Fang Zhang ◽  
Weiqi Xu ◽  
Lu Chen ◽  
Jingye Ren ◽  
...  
Keyword(s):  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Large Impact ◽  
Ccn Activity

scholarly journals Gasoline aromatics: a critical determinant of urban secondary organic aerosol formation

2017 ◽  
Vol 17 (17) ◽  
pp. 10743-10752 ◽  
Author(s):  
Jianfei Peng ◽  
Min Hu ◽  
Zhuofei Du ◽  
Yinhui Wang ◽  
Jing Zheng ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Urban Areas ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Aerosol Formation ◽  
Vehicle Exhaust ◽  
Aromatic Content ◽  
Volatile Organic

Abstract. Gasoline vehicle exhaust is an important contributor to secondary organic aerosol (SOA) formation in urban atmosphere. Fuel composition has a potentially considerable impact on gasoline SOA production, but the link between fuel components and SOA production is still poorly understood. Here, we present chamber experiments to investigate the impacts of gasoline aromatic content on SOA production through chamber oxidation approach. A significant amplification factor of 3–6 for SOA productions from gasoline exhausts is observed as gasoline aromatic content rose from 29 to 37 %. Considerably higher emission of aromatic volatile organic compounds (VOCs) using high-aromatic fuel plays an essential role in the enhancement of SOA production, while semi-volatile organic compounds (e.g., gas-phase PAHs) may also contribute to the higher SOA production. Our findings indicate that gasoline aromatics significantly influence ambient PM2. 5 concentration in urban areas and emphasize that more stringent regulation of gasoline aromatic content will lead to considerable benefits for urban air quality.

Size-resolved airborne particulate oxalic and related secondary organic aerosol species in the urban atmosphere of Chengdu, China

2015 ◽  
Vol 161-162 ◽  
pp. 134-142 ◽  
Author(s):  
Chunlei Cheng ◽  
Gehui Wang ◽  
Jingjing Meng ◽  
Qiyuan Wang ◽  
Junji Cao ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Airborne Particulate

Source apportionment and secondary organic aerosol estimation of PM2.5 in an urban atmosphere in China

2013 ◽  
Vol 57 (6) ◽  
pp. 1352-1362 ◽  
Author(s):  
XiaoFeng Huang ◽  
Hui Yun ◽  
ZhaoHeng Gong ◽  
Xiang Li ◽  
LingYan He ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Urban Atmosphere

scholarly journals Formation of highly oxygenated organic molecules from aromatic compounds

2018 ◽  
Vol 18 (3) ◽  
pp. 1909-1921 ◽  
Author(s):  
Ugo Molteni ◽  
Federico Bianchi ◽  
Felix Klein ◽  
Imad El Haddad ◽  
Carla Frege ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Urban Areas ◽  
Organic Molecules ◽  
Large Degree ◽  
Organic Aerosol ◽  
Urban Atmosphere ◽  
Chain Reaction ◽  
Volatile Organic ◽  
Single Ring ◽  
Benzene Toluene

Abstract. Anthropogenic volatile organic compounds (AVOCs) often dominate the urban atmosphere and consist to a large degree of aromatic hydrocarbons (ArHCs), such as benzene, toluene, xylenes, and trimethylbenzenes, e.g., from the handling and combustion of fuels. These compounds are important precursors for the formation of secondary organic aerosol. Here we show that the oxidation of aromatics with OH leads to a subsequent autoxidation chain reaction forming highly oxygenated molecules (HOMs) with an O : C ratio of up to 1.09. This is exemplified for five single-ring ArHCs (benzene, toluene, o-/m-/p-xylene, mesitylene (1,3,5-trimethylbenzene) and ethylbenzene), as well as two conjugated polycyclic ArHCs (naphthalene and biphenyl). We report the elemental composition of the HOMs and show the differences in the oxidation patterns of these ArHCs. A potential pathway for the formation of these HOMs from aromatics is presented and discussed. We hypothesize that AVOCs may contribute substantially to new particle formation events that have been detected in urban areas.

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