Secondary Organic Aerosol from Photooxidation of Polycyclic Aromatic Hydrocarbons

2010 ◽  
Vol 44 (21) ◽  
pp. 8134-8139 ◽  
Author(s):  
Kabindra M. Shakya ◽  
Robert J. Griffin
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Polycyclic Aromatic

The effect of gas-phase polycyclic aromatic hydrocarbons on the formation and properties of biogenic secondary organic aerosol particles

2017 ◽  
Vol 200 ◽  
pp. 143-164 ◽  
Author(s):  
Alla Zelenyuk ◽  
Dan G. Imre ◽  
Jacqueline Wilson ◽  
David M. Bell ◽  
Kaitlyn J. Suski ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Gas Phase ◽  
Aromatic Hydrocarbons ◽  
Particle Number ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Chemical Degradation ◽  
Volatile Components ◽  
Polycyclic Aromatic ◽  
Evaporation Kinetics

When secondary organic aerosol (SOA) particles are formed by ozonolysis in the presence of gas-phase polycyclic aromatic hydrocarbons (PAHs), their formation and properties are significantly different from SOA particles formed without PAHs. For all SOA precursors and all PAHs, discussed in this study, the presence of the gas-phase PAHs during SOA formation significantly affects particle mass loadings, composition, growth, evaporation kinetics, and viscosity. SOA particles formed in the presence of PAHs have, as part of their compositions, trapped unreacted PAHs and products of heterogeneous reactions between PAHs and ozone. Compared to ‘pure’ SOA particles, these particles exhibit slower evaporation kinetics, have higher fractions of non-volatile components, like oligomers, and higher viscosities, assuring their longer atmospheric lifetimes. In turn, the increased viscosity and decreased volatility provide a shield that protects PAHs from chemical degradation and evaporation, allowing for the long-range transport of these toxic pollutants. The magnitude of the effect of PAHs on SOA formation is surprisingly large. The presence of PAHs during SOA formation increases mass loadings by factors of two to five, and particle number concentrations, in some cases, by more than a factor of 100. Increases in SOA mass, particle number concentrations, and lifetime have important implications to many atmospheric processes related to climate, weather, visibility, and human health, all of which relate to the interactions between biogenic SOA and anthropogenic PAHs. The synergistic relationship between SOA and PAHs presented here are clearly complex and call for future research to elucidate further the underlying processes and their exact atmospheric implications.

scholarly journals Secondary organic aerosol formation from photooxidation of naphthalene and alkylnaphthalenes: implications for oxidation of intermediate volatility organic compounds (IVOCs)

2009 ◽  
Vol 9 (1) ◽  
pp. 1873-1905
Author(s):  
A. W. H. Chan ◽  
K. E. Kautzman ◽  
P. S. Chhabra ◽  
J. D. Surratt ◽  
M. N. Chan ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Gas Phase ◽  
Aromatic Hydrocarbons ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Aerosol Formation ◽  
Atmospheric Models ◽  
Gas Phase Reactions ◽  
Aerosol Mass ◽  
Polycyclic Aromatic

Abstract. Current atmospheric models do not include secondary organic aerosol (SOA) production from gas-phase reactions of polycyclic aromatic hydrocarbons (PAHs). Recent studies have shown that primary semivolatile emissions, previously assumed to be inert, undergo oxidation in the gas phase, leading to SOA formation. This opens the possibility that low-volatility gas-phase precursors are a potentially large source of SOA. In this work, SOA formation from gas-phase photooxidation of naphthalene, 1-methylnaphthalene (1-MN), 2-methylnaphthalene (2-MN), and 1,2-dimethylnaphthalene (1,2-DMN) is studied in the Caltech dual 28-m3 chambers. Under high-NOx conditions and aerosol mass loadings between 10 and 40 μg m

scholarly journals Relationship between chemical composition and oxidative potential of secondary organic aerosol from polycyclic aromatic hydrocarbons

2018 ◽  
Vol 18 (6) ◽  
pp. 3987-4003 ◽  
Author(s):  
Shunyao Wang ◽  
Jianhuai Ye ◽  
Ronald Soong ◽  
Bing Wu ◽  
Legeng Yu ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Chemical Composition ◽  
Aromatic Hydrocarbons ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Model Systems ◽  
Proton Nuclear Magnetic Resonance ◽  
Oxidative Potential ◽  
Redox Active ◽  
Polycyclic Aromatic

Abstract. Owing to the complex nature and dynamic behaviors of secondary organic aerosol (SOA), its ability to cause oxidative stress (known as oxidative potential, or OP) and adverse health outcomes remains poorly understood. In this work, we probed the linkages between the chemical composition of SOA and its OP, and investigated impacts from various SOA evolution pathways, including atmospheric oligomerization, heterogeneous oxidation, and mixing with metal. SOA formed from photooxidation of the two most common polycyclic aromatic hydrocarbons (naphthalene and phenanthrene) were studied as model systems. OP was evaluated using the dithiothreitol (DTT) assay. The oligomer-rich fraction separated by liquid chromatography dominates DTT activity in both SOA systems (52 ± 10 % for naphthalene SOA (NSOA), and 56 ± 5 % for phenanthrene SOA (PSOA)). Heterogeneous ozonolysis of NSOA was found to enhance its OP, which is consistent with the trend observed in selected individual oxidation products. DTT activities from redox-active organic compounds and metals were found to be not additive. When mixing with highly redox-active metal (Cu), OP of the mixture decreased significantly for 1,2-naphthoquinone (42 ± 7 %), 2,3-dihydroxynaphthalene (35 ± 1 %), NSOA (50 ± 6 %), and PSOA (43 ± 4 %). Evidence from proton nuclear magnetic resonance (1H NMR) spectroscopy illustrates that such OP reduction upon mixing can be ascribed to metal–organic binding interactions. Our results highlight the role of aerosol chemical composition under atmospheric aging processes in determining the OP of SOA, which is needed for more accurate and explicit prediction of the toxicological impacts from particulate matter.

scholarly journals Relationship between Chemical Composition and Oxidative Potential of Secondary Organic Aerosol from Polycyclic Aromatic Hydrocarbons

2017 ◽  
Author(s):  
Shunyao Wang ◽  
Jianhuai Ye ◽  
Ronald Soong ◽  
Bing Wu ◽  
Legeng Yu ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Chemical Composition ◽  
Aromatic Hydrocarbons ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Model Systems ◽  
Proton Nuclear Magnetic Resonance ◽  
Oxidative Potential ◽  
Redox Active ◽  
Polycyclic Aromatic

Abstract. Owing to the complex nature and dynamic behaviors of secondary organic aerosol (SOA), its ability to cause oxidative stress (known as oxidative potential, or OP) and adverse health outcomes remain poorly understood. In this work, we probed into linkages between the chemical composition of SOA and its OP, and investigated impacts from various SOA evolution pathways, including atmospheric oligomerization, heterogeneous oxidation and mixing with metal. SOA formed from photooxidation of the two most common polycyclic aromatic hydrocarbons (naphthalene and phenanthrene) were studied as model systems. OP was evaluated using the dithiothreitol (DTT) assay. The oligomer-rich fraction separated by liquid chromatography contributed significantly to DTT activity in both SOA systems (52 ± 10 % for NSOA and 56 ± 5 % for PSOA). Heterogeneous ozonolysis of NSOA was found to enhance its OP, which is consistent with the trend observed in selected individual oxidation products. DTT activities from redox-active organic compounds and metals were found to be not additive. When mixing with highly redox-active metal (Cu), OP of the mixture decreased significantly for 1, 2-naphthoquinone (42 ± 7 %), 2, 3-dihydroxynaphthalene (35 ± 1 %), NSOA (50±6%) and PSOA (43 ± 4 %). Evidence from proton nuclear magnetic resonance (1H NMR) spectroscopy illustrates that such OP reduction upon mixing can be ascribed to metal-organic binding interactions. Our results highlight the role of aerosol chemical composition under atmospheric aging processes in determining the OP of SOA, which is needed for a more accurate and explicit prediction of the toxicological impacts from particulate matter.

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