Secondary organic aerosol formation from &amp;lt;i&amp;gt;m&amp;lt;/i&amp;gt;-xylene, toluene, and benzene

Ng, N. L.; Kroll, J. H.; Chan, Arthur W. H.; Chhabra, P. S.; Flagan, Richard C.; Seinfeld, John H.

doi:10.5194/acp-7-3909-2007

Cited by 762 publications

(895 citation statements)

References 49 publications

Supporting

Mentioning

795

Contrasting

Unclassified

Order By: Relevance

“…Substituted aromatics such as 1,3,5-TMB and o-xylene are commonly referred to as low-yield aromatics, due to their lower yield compared to high-yield aromatics such as toluene or benzene. reported yields within the range of 3-5 % and 7-10 % for the low-yield and high-yield aromatics, which have been confirmed by other studies (Cocker et al, 2001;Ng et al, 2007;Healy et al, 2008). These values agree with the yields obtained in most of our anthropogenic experiments.…”

Section: Soa Concentration and Yieldsupporting

confidence: 92%

See 1 more Smart Citation

Experimental data on SOA formation from mixtures of anthropogenic and biogenic organic compounds

Vivanco¹,

Santiago²,

Sánchez³

et al. 2013

Atmósfera

View full text Add to dashboard Cite

RESUMENLos aerosoles orgánicos secundarios (AOS) constituyen una fracción de las partículas atmosféricas. Este tipo de partículas se forman como consecuencia de la reacción de oxidación de ciertos gases orgánicos, lo que conduce a la formación de compuestos de baja volatilidad. Del mismo modo que para otros contaminantes atmosféricos, los modelos de calidad del aire permiten la simulación de partículas, una herramienta muy útil en tareas de gestión de la calidad del aire. Sin embargo, el uso adecuado de estos modelos debe basarse en la validación de su capacidad para reproducir las concentraciones observadas. Las estaciones de monitoreo de la calidad del aire registran información sobre una amplia variedad de contaminantes atmosféricos. Desafortunadamente, no se dispone habitualmente de medidas de AOS, ya que la instrumentación que se tiene en dichas redes de monitoreo no permite la diferenciación de las fuentes primarias y secundarias de los aerosoles orgánicos. Este documento presenta una serie de experimentos de fotooxidación realizados en las cámaras de simulación del Fotorreactor Europeo (CEAM, España) en diferentes condiciones experimentales con objeto de obtener datos sobre la formación de AOS. El uso de este tipo de cámaras permite aislar los procesos químicos y de formación de aerosoles, por lo que los datos presentados en este estudio tienen un considerable valor para propósitos de evaluación de modelos de formación de AOS, al igual que para el estudio del comportamiento de este tipo de partículas. ABSTRACTSecondary organic aerosols (SOA) constitute a significant fraction of the atmospheric particulate matter. Theses particles are formed as a consequence of the oxidation reaction of certain organic gases that leads to the formation of low-volatility compounds. As for other pollutants, air quality models allow the simulation of particle levels and thus models constitute a powerful tool in air quality management. Nevertheless, the Atmósfera 26(1), 59-73 (2013) 60 M. G. Vivanco et al. accepted use of models must be based on the validation of its capacity to reproduce observed concentrations. Air monitoring sites provide measured information of a large variety of ambient pollutants. Unfortunately, measurements on SOA are not normally available, as current monitoring networks do not include instrumentation to distinguish primary from secondary sources of organic carbonaceous aerosol. This paper presents a set of photooxidation experiments performed in the European Photorreactor (EUPHORE) smog chamber (CEAM, Spain) under different experimental conditions to investigate SOA formation. The use of chambers allows the isolation of atmospheric chemistry and aerosol formation processes. Thus, although these measurements were obtained at initial precursor concentrations higher than those in atmospheric conditions, they constitute a valuable set of information for SOA model evaluation purposes.

show abstract

Section: Soa Concentration and Yieldsupporting

confidence: 92%

“…We considered density values of 1.0 and 1.5 g/cm 3 , in order to account for the range of density values reported by previous studies Ng et al, 2007). Dilution and wall-losses corrections were calculated by considering the particle loss as a first order rate process.…”

Section: Soa Concentration and Yieldmentioning

confidence: 99%

Experimental data on SOA formation from mixtures of anthropogenic and biogenic organic compounds

Vivanco¹,

Santiago²,

Sánchez³

et al. 2013

Atmósfera

View full text Add to dashboard Cite

show abstract

“…First, SOA mass yields determined in the laboratory may not be representative for the conditions in the real atmosphere and recent research has focused on this question. Mass yields were found to depend strongly on NO x levels, for example, and can be higher than previously reported (27). Second, the main anthropogenic precursors of SOA may not be measured by current methods.…”

Section: Urban Sourcesmentioning

confidence: 61%

Organic Aerosols in the Earth’s Atmosphere

Gouw

Jimenez²

2009

Environ. Sci. Technol.

393

303

View full text Add to dashboard Cite

Organic particles are abundant in the troposphere and important for air quality and climate, but what are their sources?Aerosols, microscopically small particles suspended in air, are an important species in the Earth's atmosphere and influence both air quality and climate. Aerosols are small enough to penetrate deep into the lungs of people and have been linked to severe short-and long-term health effects such as asthma, cardio-respiratory disease, and lung cancer. Aerosols impact the Earth's climate directly through the scattering and absorption of solar radiation, and indirectly through their role as cloud-condensation nuclei. A large fraction (∼50%) of the submicron aerosol mass in the troposphere consists of organic material (1, 2). Direct emissions of organic aerosol (primary organic aerosol or POA) are distinguished from secondary organic aerosol (SOA) formed in the atmosphere from gas-phase precursors. Both POA and the precursors of SOA can be from urban, biogenic, and biomass burning sources. Our understanding of each of these sources is limited at present (3, 4), which hinders the efforts to mitigate the adverse effects. In this feature article, we briefly review the latest insights from field studies into the sources of organic aerosol (OA). Many results were obtained using two relatively new methods for quantifying OA on time scales of minutes: particle-into-liquid sampling combined with total organic carbon analysis for measurements of water-soluble organic carbon (5) and aerosol mass spectrometry (AMS) (6); both have been evaluated in detail against other reported methods, both in terms of the mass loading (7-10) as well as the source apportionment (11-13) of organic aerosol. Urban SourcesGlobal models predict that urban sources of OA are small compared with biomass burning emissions and biogenic SOA formation (4). Nevertheless, several recent studies found that OA was well correlated with tracers of urban pollution such as CO, acetylene (C 2 H 2 ), iso-propylnitrate, and odd oxygen (O 3 + NO 2 ) (8,(14)(15)(16)(17), suggesting that the influence of urban emissions may be larger than previously recognized. These studies showed that the good correlation is not due to emissions of POA, but to a rapid growth of SOA in urban air that overwhelms the direct POA emissions within a few hours of photochemical processing (8,(18)(19)(20).The atmospheric variability in OA is due to the spatial distribution of emissions, transport, chemical transformation, and removal by deposition. By normalizing OA to an inert combustion tracer such as CO or acetylene, the variability due to emissions and transport can be accounted for to a certain extent (8). Enhancement ratios of OA versus CO are denoted as ∆OA/∆CO, where ∆ indicates the excess amount over the background concentration. Accounting for backgrounds is important particularly when using a long-lived species such as CO. In practice, enhancement ratios are often calculated from correlation slopes between OA and CO (7). CO can also be formed from biogenic volatile ...

show abstract

“…Secondly, the presence of NO x increased the SOA formation from 1.6 215 % to 9.7 %. This increment differs from the studies performed by Ng et al 2007. This could be 216 explained by changes in peroxy radical chemistry, e.g., effect of aerosol seeds (Klotz et al, 217…”

Section: Gas-phase Products and Aerosol Profiles 168mentioning

confidence: 82%