Volume 200, 2017

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

Abstract

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.

Associated articles

Article information

Article type
Paper
Submitted
22 jan 2017
Accepted
21 feb 2017
First published
21 feb 2017

Faraday Discuss., 2017,200, 143-164

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

A. Zelenyuk, D. G. Imre, J. Wilson, D. M. Bell, K. J. Suski, M. Shrivastava, J. Beránek, M. L. Alexander, A. L. Kramer and S. L. Massey Simonich, Faraday Discuss., 2017, 200, 143 DOI: 10.1039/C7FD00032D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements