scholarly journals Secondary Organic Aerosol Formation from Isoprene: Selected Research, Historic Account and State of the Art

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 728
Author(s):  
Magda Claeys ◽  
Willy Maenhaut
Keyword(s):  
Molecular Characterization ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Quality Data ◽  
Formation Mechanisms ◽  
Aerosol Formation ◽  
Fine Aerosol ◽  
Aerosol Sources ◽  
Different Sources

In this review, we cover selected research on secondary organic aerosol (SOA) formation from isoprene, from the beginning of research, about two decades ago, to today. The review begins with the first observations of isoprene SOA markers, i.e., 2-methyltetrols, in ambient fine aerosol and focuses on studies dealing with molecular characterization, speciation, formation mechanisms, and source apportionment. A historic account is given on how research on isoprene SOA has developed. The isoprene SOA system is rather complex, with different pathways being followed in pristine and polluted conditions. For SOA formation from isoprene, acid-catalyzed hydrolysis is necessary, and sulfuric acid enhances SOA by forming additional nonvolatile products such as organosulfates. Certain results reported in early papers have been re-interpreted in the light of recent results; for example, the formation of C5-alkene triols. Attention is given to mass spectrometric and separation techniques, which played a crucial role in molecular characterization. The unambiguous structural characterization of isoprene SOA markers has been achieved, owing to the preparation of reference compounds. Efforts have also been made to use air quality data to estimate the influence of biogenic and pollution aerosol sources. This review examines the use of an organic marker-based method and positive matrix factorization to apportion SOA from different sources, including isoprene SOA.

scholarly journals Molecular Characterization of Organosulfur Compounds in Biodiesel and Diesel Fuel Secondary Organic Aerosol

2016 ◽  
Vol 51 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Sandra L. Blair ◽  
Amanda C. MacMillan ◽  
Greg T. Drozd ◽  
Allen H. Goldstein ◽  
Rosalie K. Chu ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Diesel Fuel ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Organosulfur Compounds

Particulate matter emissions over the oil sands regions in Alberta, Canada

2017 ◽  
Vol 25 (4) ◽  
pp. 432-443 ◽  
Author(s):  
Zhenyu Xing ◽  
Ke Du
Keyword(s):  
Particulate Matter ◽  
Oil Sands ◽  
Secondary Organic Aerosol ◽  
Ambient Air ◽  
Organic Aerosol ◽  
Open Pit ◽  
Open Pit Mining ◽  
Formation Mechanisms ◽  
Aerosol Formation ◽  
Secondary Aerosol

Particulate matter (PM) emissions from the expanded oil sands development in Alberta are becoming a focus among the aerosol science community because of its significant negative impact on the regional air quality and climate change. Open-pit mining, petroleum coke (petcoke) dust, and the transportation of oil sands and waste materials by heavy-duty trucks on unpaved roads could release PM into the air. Incomplete combustion of fossil fuels by engines and stationary boilers leads to the formation of carbonaceous aerosols. In addition, wildfire and biogenic emissions surrounding the oil sands regions also have the potential to contribute primary PM to the ambient air. Secondary organic aerosol formation has been revealed as an important source of PM over nearby and distant areas from the oil sands regions. This review summarizes the primary PM sources and some secondary aerosol formation mechanisms that are linked to oil sands development. It also reviews the approaches that can be applied in aerosol source apportionment. Meteorological condition is an important factor that may influence the primary PM emission and secondary aerosol formation in Alberta’s oil sands regions. Current concern should not be limited to the primary emission of atmospheric PM. Secondary formation of aerosols, especially secondary organic aerosol originating from photochemical reaction, should also be taken into consideration. To obtain a more comprehensive understanding of the sources and amount of PM emissions based on the bottom-up emission inventory approach, investigations on how to reduce the uncertainty in determination of real-world PM emission factors for the variable sources are needed. Long-range transport trajectories of fine PM from Alberta’s oil sands regions remain unknown.

Insights into Secondary Organic Aerosol Formation Mechanisms from Measured Gas/Particle Partitioning of Specific Organic Tracer Compounds

2013 ◽  
Vol 47 (8) ◽  
pp. 3781-3787 ◽  
Author(s):  
Yunliang Zhao ◽  
Nathan M. Kreisberg ◽  
David R. Worton ◽  
Gabriel Isaacman ◽  
Robin J. Weber ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Formation Mechanisms ◽  
Aerosol Formation ◽  
Secondary Organic Aerosol Formation

scholarly journals Real-time, controlled OH-initiated oxidation of biogenic secondary organic aerosol

2012 ◽  
Vol 12 (3) ◽  
pp. 8183-8224 ◽  
Author(s):  
J. G. Slowik ◽  
J. P. S. Wong ◽  
J. P. D. Abbatt
Keyword(s):  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Aerosol Formation ◽  
Organic Mass ◽  
Ambient Aerosol ◽  
Atmospheric Processing

Abstract. The chemical complexity of atmospheric organic aerosol (OA) requires novel methods for characterization of its components and description of its atmospheric processing-induced transformations. We present the first field deployment of the Toronto Photooxidation Tube (TPOT), a field-deployable flow reactor for the controlled exposure of ambient aerosol to OH radicals. The system alternates between sampling of (1) unreacted ambient aerosol, (2) aerosol subjected to a ~4 °C temperature increase, and (3) aerosol that is both heated and oxidized by OH. This allows both characterization of the aging process and classification of aerosol in terms of its volatility and reaction-based properties. Summertime measurements by an aerosol mass spectrometer coupled to the TPOT were performed in the remote forest of Western Canada, resulting in aerosol dominated by biogenic secondary organic aerosol. Volatilization resulted in an approximately 10 to 25% decrease in organic mass and resulted in a slight increase in oxygenation. OH oxidation resulted in a further organic mass decrease (additional ~25%) and yielded an aerosol with O:C values comparable to those characteristic of low volatility, highly oxygenated OA. Most OH-induced changes occurred within the equivalent of ~3 days of atmospheric processing, with further reactions generally proceeding at a greatly reduced rate. Positive matrix factorization (PMF) analysis of the TPOT data yielded five factors. One factor is related to primary biomass burning organic aerosol, while the others describe oxygenated organic aerosol (OOA) components in terms of reactivity and volatility: (1) volatile and reactive; (2) non-volatile and reactive; (3) non-volatile and reactive early-generation product; (4) non-volatile and non-reactive product. This PMF classification of aerosol components directly in terms of reactivity and volatility is enabled by the TPOT-modulated perturbation of aerosol composition, and is not otherwise accessible. The particle-phase reaction end products have mass spectra similar to the low-volatility oxygenated organic aerosol (LV-OOA) factors widely reported in the literature, providing supporting evidence for aged organic aerosol formation from OH-driven oxidation processes.

Modelling of secondary organic aerosol formation from isoprene photooxidation chamber studies using different approaches

2013 ◽  
Vol 10 (3) ◽  
pp. 194 ◽  
Author(s):  
Haofei Zhang ◽  
Harshal M. Parikh ◽  
Jyoti Bapat ◽  
Ying-Hsuan Lin ◽  
Jason D. Surratt ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Gas Phase ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Basis Set ◽  
Chemical Mechanism ◽  
Formation Mechanisms ◽  
Aerosol Formation ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere

Environmental context Fine particulate matter (PM2.5) in the Earth’s atmosphere plays an important role in climate change and human health, in which secondary organic aerosol (SOA) that forms from the photooxidation of volatile organic compounds (VOCs) has a significant contribution. SOA derived from isoprene, the most abundant non-methane VOC emitted into the Earth’s atmosphere, has been widely studied to interpret its formation mechanisms. However, the ability to predict isoprene SOA using current models remains difficult due to the lack of understanding of isoprene chemistry. Abstract Secondary organic aerosol (SOA) formation from the photooxidation of isoprene was simulated against smog chamber experiments with varied concentrations of isoprene, nitrogen oxides (NOx=NO + NO2) and ammonium sulfate seed aerosols. A semi-condensed gas-phase isoprene chemical mechanism (ISO-UNC) was coupled with different aerosol-phase modelling frameworks to simulate SOA formation, including: (1) the Odum two-product approach, (2) the 1-D volatility basis-set (VBS) approach and (3) a new condensed kinetic model based upon the gas-particle partitioning theory and reactive uptake processes. The first two approaches are based upon empirical parameterisations from previous studies. The kinetic model uses a gas-phase mechanism to explicitly predict the major intermediate precursors, namely the isoprene-derived epoxides, and hence simulate SOA formation. In general, they all tend to significantly over predict SOA formation when semivolatile concentrations are higher because more semivolatiles are forced to produce SOA in the models to maintain gas-particle equilibrium; yet the data indicate otherwise. Consequently, modified dynamic parameterised models, assuming non-equilibrium partitioning, were incorporated and could improve the model performance. In addition, the condensed kinetic model was expanded by including an uptake limitation representation so that reactive uptake processes slow down or even stop; this assumes reactive uptake reactions saturate seed aerosols. The results from this study suggest that isoprene SOA formation by reactive uptake of gas-phase precursors is likely limited by certain particle-phase features, and at high gas-phase epoxide levels, gas-particle equilibrium is not obtained. The real cause of the limitation needs further investigation; however, the modified kinetic model in this study could tentatively be incorporated in large-scale SOA models given its predictive ability.

scholarly journals Secondary organic aerosol formation from the β-pinene+NO<sub>3</sub> system: effect of humidity and peroxy radical fate

2015 ◽  
Vol 15 (13) ◽  
pp. 7497-7522 ◽  
Author(s):  
C. M. Boyd ◽  
J. Sanchez ◽  
L. Xu ◽  
A. J. Eugene ◽  
T. Nah ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Peroxy Radical ◽  
Organic Aerosol ◽  
Formation Mechanisms ◽  
Organic Nitrate ◽  
Organic Nitrates ◽  
Aerosol Formation ◽  
System Effect ◽  
Aerosol Mass ◽  
Wide Range

Abstract. The formation of secondary organic aerosol (SOA) from the oxidation of β-pinene via nitrate radicals is investigated in the Georgia Tech Environmental Chamber (GTEC) facility. Aerosol yields are determined for experiments performed under both dry (relative humidity (RH) < 2 %) and humid (RH = 50 % and RH = 70 %) conditions. To probe the effects of peroxy radical (RO2) fate on aerosol formation, "RO2 + NO3 dominant" and "RO2 + HO2 dominant" experiments are performed. Gas-phase organic nitrate species (with molecular weights of 215, 229, 231, and 245 amu, which likely correspond to molecular formulas of C10H17NO4, C10H15NO5, C10H17NO5, and C10H15NO6, respectively) are detected by chemical ionization mass spectrometry (CIMS) and their formation mechanisms are proposed. The NO+ (at m/z 30) and NO2+ (at m/z 46) ions contribute about 11 % to the combined organics and nitrate signals in the typical aerosol mass spectrum, with the NO+ : NO2+ ratio ranging from 4.8 to 10.2 in all experiments conducted. The SOA yields in the "RO2 + NO3 dominant" and "RO2 + HO2 dominant" experiments are comparable. For a wide range of organic mass loadings (5.1–216.1 μg m−3), the aerosol mass yield is calculated to be 27.0–104.1 %. Although humidity does not appear to affect SOA yields, there is evidence of particle-phase hydrolysis of organic nitrates, which are estimated to compose 45–74 % of the organic aerosol. The extent of organic nitrate hydrolysis is significantly lower than that observed in previous studies on photooxidation of volatile organic compounds in the presence of NOx. It is estimated that about 90 and 10 % of the organic nitrates formed from the β-pinene+NO3 reaction are primary organic nitrates and tertiary organic nitrates, respectively. While the primary organic nitrates do not appear to hydrolyze, the tertiary organic nitrates undergo hydrolysis with a lifetime of 3–4.5 h. Results from this laboratory chamber study provide the fundamental data to evaluate the contributions of monoterpene + NO3 reaction to ambient organic aerosol measured in the southeastern United States, including the Southern Oxidant and Aerosol Study (SOAS) and the Southeastern Center for Air Pollution and Epidemiology (SCAPE) study.

scholarly journals Kinetic modeling of secondary organic aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

2007 ◽  
Vol 7 (15) ◽  
pp. 4135-4147 ◽  
Author(s):  
A. W. H. Chan ◽  
J. H. Kroll ◽  
N. L. Ng ◽  
J. H. Seinfeld
Keyword(s):  
Gas Phase ◽  
Secondary Organic Aerosol ◽  
Laboratory Data ◽  
Organic Aerosol ◽  
Formation Mechanisms ◽  
Hydrocarbon Oxidation ◽  
Phase Reaction ◽  
Particle Phase ◽  
Aerosol Formation ◽  
Kinetics Of

Abstract. The distinguishing mechanism of formation of secondary organic aerosol (SOA) is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics), of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

scholarly journals Kinetic modeling of Secondary Organic Aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

2007 ◽  
Vol 7 (3) ◽  
pp. 7051-7085 ◽  
Author(s):  
A. W. H. Chan ◽  
J. H. Kroll ◽  
N. L. Ng ◽  
J. H. Seinfeld
Keyword(s):  
Gas Phase ◽  
Secondary Organic Aerosol ◽  
Laboratory Data ◽  
Organic Aerosol ◽  
Formation Mechanisms ◽  
Hydrocarbon Oxidation ◽  
Phase Reaction ◽  
Particle Phase ◽  
Aerosol Formation ◽  
Kinetics Of

Abstract. The distinguishing mechanism of formation of secondary organic aerosol (SOA) is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics), of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

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