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Chemical And Physical Studies Of Secondary Organic Aerosol Formed From Beta Pinene Photooxidation
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Book Synopsis Chemical and Physical Studies of Secondary Organic Aerosol Formed from Beta-pinene Photooxidation by : Mehrnaz Sarrafzadeh
Download or read book Chemical and Physical Studies of Secondary Organic Aerosol Formed from Beta-pinene Photooxidation written by Mehrnaz Sarrafzadeh and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric organic aerosols have a significant impact on climate and human health. However, our understanding of the physical and chemical properties of these aerosols is inadequate, thus their climate and health influences are poorly constrained. In this study, we investigated the secondary organic aerosol (SOA) formation from OH-initiated oxidation of -pinene. The majority of experiments were conducted in the York University smog chamber. The main objective was to identify the gas and particle phase products with an atmospheric pressure chemical ionization mass spectrometer (APCI-MS/MS). A wide variety of products were identified containing various functional groups including alcohol, aldehyde, carboxylic acid, ketone and nitrate. Following the chemical composition characterization of products, the shape, phase state and density of generated particles were determined. Images from a scanning electron microscope (SEM) revealed that SOA particles from -pinene were commonly spherical in shape, and adopted an amorphous semi-solid/liquid state. Additionally, the density was determined for SOA particles generated from -pinene/OH, nopinone/OH and nopinone/NO3 experiments for the first time using a tapered element oscillating microbalance-scanning mobility particle sizer (TEOM-SMPS) method. Our results showed a correlation between the determined particle density and the particle chemical composition of the respective system. This demonstrates that changes in particle density can be indicative of the changes in chemical composition of particles. We also investigated the chemical aging of oxidation products by exposing them to additional OH radicals or ozone. The observed changes in chemical composition of products and additional SOA mass production during OH-induced aging were attributed to further oxidation of gas phase intermediate products. The NOx dependence of SOA formation from -pinene photooxidation was investigated in the York University smog chamber and the Jlich Plant Atmosphere Chamber (JPAC). Consistent with previous NOx studies, SOA yields increased with increasing [NOx] at low-NOx conditions, whereas increasing [NOx] at high-NOx conditions suppressed the SOA yield. This increase was attributed to an increase of OH concentration. After removing the effect of [OH] on SOA yield in the JPAC, SOA yields only decreased with increasing [NOx]. Finally, the formation mechanisms of identified products were probed based on the information acquired throughout our study.
Book Synopsis Chemical and Physical Characterization of Secondary Organic Aerosol Formation from Select Agricultural Emissions by : Quentin Gerald James Malloy
Download or read book Chemical and Physical Characterization of Secondary Organic Aerosol Formation from Select Agricultural Emissions written by Quentin Gerald James Malloy and published by . This book was released on 2009 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Chemistry of Secondary Organic Aerosol by : Lindsay Diana Yee
Download or read book Chemistry of Secondary Organic Aerosol written by Lindsay Diana Yee and published by . This book was released on 2013 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The photooxidation of volatile organic compounds (VOCs) in the atmosphere can lead to the formation of secondary organic aerosol (SOA), a major component of fine particulate matter. Improvements to air quality require insight into the many reactive intermediates that lead to SOA formation, of which only a small fraction have been measured at the molecular level. This thesis describes the chemistry of secondary organic aerosol (SOA) formation from several atmospherically relevant hydrocarbon precursors. Photooxidation experiments of methoxyphenol and phenolic compounds and C12 alkanes were conducted in the Caltech Environmental Chamber. These experiments include the first photooxidation studies of these precursors run under sufficiently low NOx levels, such that RO2 + HO2 chemistry dominates, an important chemical regime in the atmosphere. Using online Chemical Ionization Mass Spectrometery (CIMS), key gas-phase intermediates that lead to SOA formation in these systems were identified. With complementary particle-phase analyses, chemical mechanisms elucidating the SOA formation from these compounds are proposed. Three methoxyphenol species (phenol, guaiacol, and syringol) were studied to model potential photooxidation schemes of biomass burning intermediates. SOA yields (ratio of mass of SOA formed to mass of primary organic reacted) exceeding 25% are observed. Aerosol growth is rapid and linear with the organic conversion, consistent with the formation of essentially non-volatile products. Gas and aerosol-phase oxidation products from the guaiacol system show that the chemical mechanism consists of highly oxidized aromatic species in the particle phase. Syringol SOA yields are lower than that of phenol and guaiacol, likely due to unique chemistry dependent on methoxy group position. The photooxidation of several C12 alkanes of varying structure n-dodecane, 2-methylundecane, cyclododecane, and hexylcyclohexane) were run under extended OH exposure to investigate the effect of molecular structure on SOA yields and photochemical aging. Peroxyhemiacetal formation from the reactions of several multifunctional hydroperoxides and aldehyde intermediates was found to be central to organic growth in all systems, and SOA yields increased with cyclic character of the starting hydrocarbon. All of these studies provide direction for future experiments and modeling in order to lessen outstanding discrepancies between predicted and measured SOA.
Book Synopsis Molecular Composition, Volatility, and Formation Mechanisms of Biogenic Secondary Organic Aerosol by : Emma Louise D'Ambro
Download or read book Molecular Composition, Volatility, and Formation Mechanisms of Biogenic Secondary Organic Aerosol written by Emma Louise D'Ambro and published by . This book was released on 2018 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Chemical Characterization of Biogenic Secondary Organic Aerosol Generated from the Oxidation of Plant and Leaf Litter Emissions by : Celia L. Faiola
Download or read book Chemical Characterization of Biogenic Secondary Organic Aerosol Generated from the Oxidation of Plant and Leaf Litter Emissions written by Celia L. Faiola and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosol impact climate by scattering and absorbing radiation and contributing to cloud formation processes. One of the largest uncertainties in climate change predictions is due to limitations in our understanding of the formation of secondary organic aerosol (SOA). This dissertation investigated SOA formation from the oxidation of plant and leaf litter emissions in a laboratory chamber. To accurately measure the biogenic volatile organic compound (BVOC) emissions, a dynamic dilution system was developed and is described in the first study. This system was used to calibrate the GC-MS-FID and improve quantitation with a maximum instrumental error of +/-10%. In the second study, two separate sets of soil and leaf litter samples were transported from the University of Idaho experimental forest and brought back to the lab. The BVOC emissions from these samples were pumped to an aerosol growth chamber where they were oxidized to generate SOA. The resulting SOA composition was similar to SOA formed from the oxidation of other biogenic SOA precursors. Soil/leaf litter BVOC missions were compared to a canopy emission model and contributed from 12-136% of canopy emissions during spring and fall. Results suggest this could be a significiant emission source during those times of the year. In the third and fourth study, coniferous plants were treated with a plant hormone, methyl jasmonate, to simulate herbivory stress. The third study focused on the plant responses to the stress treatment by investigating changes to the BVOC emission profile. There was a high degree of inter- and intra-plant species variability. Some of the compounds most affected by the stress treatment were alpha-pinene, beta-pinene, limonene, 1,8-cineol, beta-myrcene, terpinolene, and the aromatic cymene isomers. The fourth study investigated changes to SOA composition due to changes in the BVOC emission profiles. Most pre-treatment SOA was very similar in composition with Pearson correlation coefficients between the AMS spectra greater than 0.88. The SOA generated after MeJA treatment produced aerosol mass spectra with similar m/z enhancements. This could indicate an herbivory stress mass spectral fingerprint that could be used to identify plant stress at an ecosystem scale.
Book Synopsis Fundamentals of Chemical Reaction Engineering by : Mark E. Davis
Download or read book Fundamentals of Chemical Reaction Engineering written by Mark E. Davis and published by Courier Corporation. This book was released on 2013-05-27 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Appropriate for a one-semester undergraduate or first-year graduate course, this text introduces the quantitative treatment of chemical reaction engineering. It covers both homogeneous and heterogeneous reacting systems and examines chemical reaction engineering as well as chemical reactor engineering. Each chapter contains numerous worked-out problems and real-world vignettes involving commercial applications, a feature widely praised by reviewers and teachers. 2003 edition.
Book Synopsis Chemical and Physical Investigation of Secondary Organic Aerosol Formation by : Shunsuke Nakao
Download or read book Chemical and Physical Investigation of Secondary Organic Aerosol Formation written by Shunsuke Nakao and published by . This book was released on 2012 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Atmospheric Aerosols by : Rekha Kale
Download or read book Atmospheric Aerosols written by Rekha Kale and published by Scitus Academics LLC. This book was released on 2015-03 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric Aerosols is a vital problem in current environmental research due to its importance in atmospheric optics, energetics, radiative transfer studies, chemistry, climate, biology and public health. Aerosols can influence the energy balance of the terrestrial atmosphere, the hydrological cycle, atmospheric dynamics and monsoon circulations. Because of the heterogeneous aerosol field with large spatial and temporal variability and reduction in uncertainties in aerosol quantification is a challenging task in atmospheric sciences. Keeping this in view the present study aims to assess the impact of aerosols on coastal Indian station Visakhapatnam and the adjoining Bay of Bengal. An aerosol is a colloid of fine solid particles or liquid droplets, in air or another gas. Aerosols can be natural or not. Examples of natural aerosols are fog, forest exudates and geyser steam.
Book Synopsis Laboratory Studies on the Formation of Secondary Organic Aerosol from the Atmospheric Oxidation of Alkenes by : Kenneth Stephen Docherty
Download or read book Laboratory Studies on the Formation of Secondary Organic Aerosol from the Atmospheric Oxidation of Alkenes written by Kenneth Stephen Docherty and published by . This book was released on 2004 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Physical and Chemical Processes in the Formation of Biogenic Secondary Organic Aerosols by : Åsa Jonsson
Download or read book Physical and Chemical Processes in the Formation of Biogenic Secondary Organic Aerosols written by Åsa Jonsson and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Atmospheric Multiphase Chemistry by : Hajime Akimoto
Download or read book Atmospheric Multiphase Chemistry written by Hajime Akimoto and published by John Wiley & Sons. This book was released on 2020-06-02 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important guide that highlights the multiphase chemical processes for students and professionals who want to learn more about aerosol chemistry Atmospheric Multiphase Reaction Chemistry provides the information and knowledge of multiphase chemical processes and offers a review of the fundamentals on gas-liquid equilibrium, gas phase reactions, bulk aqueous phase reactions, and gas-particle interface reactions related to formation of secondary aerosols. The authors—noted experts on the topic—also describe new particle formation, and cloud condensation nuclei activity. In addition, the text includes descriptions of field observations on secondary aerosols and PM2.5. Atmospheric aerosols play a critical role in air quality and climate change. There is growing evidence that the multiphase reactions involving heterogeneous reactions on the air-particle interface and the reactions in the bulk liquid phase of wet aerosol and cloud/fog droplets are important processes forming secondary aerosols in addition to gas-phase oxidation reactions to form low-volatile compounds. Comprehensive in scope, the book offers an understanding of the topic by providing a historical overview of secondary aerosols, the fundamentals of multiphase reactions, gas-phase reactions of volatile organic compounds, aqueous phase and air-particle interface reactions of organic compound. This important text: Provides knowledge on multiphase chemical processes for graduate students and research scientists Includes fundamentals on gas-liquid equilibrium, gas phase reactions, bulk aqueous phase reactions, and gas-particle interface reactions related to formation of secondary aerosols Covers in detail reaction chemistry of secondary organic aerosols Written for students and research scientists in atmospheric chemistry and aerosol science of environmental engineering, Atmospheric Multiphase Reaction Chemistry offers an essential guide to the fundamentals of multiphase chemical processes.
Book Synopsis Characterization of Secondary Organic Aerosols in the Atmosphere by Using Mass Spectrometric Approaches by : Farhat Yasmeen
Download or read book Characterization of Secondary Organic Aerosols in the Atmosphere by Using Mass Spectrometric Approaches written by Farhat Yasmeen and published by . This book was released on 2010 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric aerosol. The chemical composition of SOA is highly uncertain as it depends on different ongoing chemical and physical processes of biogenic volatile organic compounds (BVOC) and anthropogenic volatile organic compounds in the atmosphere. The research performed within the frame of this doctoral thesis is focused on the characterization of SOA produced from BVOC under a variety of atmospheric reactions resorting to mass spectrometric approaches. In a first study, the aqueous-phase oligomer formation of a major atmospheric photooxidation product, i.e., methylglyoxal, has been investigated to explore an additional pathway producing SOA through cloud processes during night-time. A second study deals with the chemical characterization (sulfate and organic matter) of marine aerosols. methanesulfonic acid was the dominating organic compound in in the fine size fraction of aerosol. A third study concerns the structural characterization of a dimeric [alpha]- and [beta]-pinene SOA product. It is proposed that diaterpenylic acid is a key monomeric unit for dimers of the ester type. A fourth study deals with the chemical characterization by fragmentation of major terpenoic acids in ambient fine aerosols from a rural site. Emphasis is given to the mass spectrometric differentiation of isobaric terpenoic acids that occur in fine forest aerosol. This thesis presents results on aerosol characterization from a wide range of parent organic compounds under a variety of atmospheric conditions.
Book Synopsis Influence of Environmental Parameters on Secondary Organic Aerosol Formation by : Bethany A. Warren
Download or read book Influence of Environmental Parameters on Secondary Organic Aerosol Formation written by Bethany A. Warren and published by . This book was released on 2008 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Formation and Aging of Secondary Organic Aerosol from Alpha-pinene Oxidation by : Kaytlin Henry
Download or read book The Formation and Aging of Secondary Organic Aerosol from Alpha-pinene Oxidation written by Kaytlin Henry and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Evolution of Secondary Organic Aerosol Composition, Volatility, and Absorption During Oxidation of Phenolic Compounds Under Conditions Relevant to Biomass Burning by : Carley Fredrickson
Download or read book Evolution of Secondary Organic Aerosol Composition, Volatility, and Absorption During Oxidation of Phenolic Compounds Under Conditions Relevant to Biomass Burning written by Carley Fredrickson and published by . This book was released on 2021 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phenolic compounds emitted from wildfires and biomass burning (BB) are highly reactive and yield secondary organic aerosol (SOA) and brown carbon (BrC) upon oxidation initiated by the hydroxyl radical (OH) and nitrate radical (NO3). In high nitrogen dioxide (NO2) environments, such as BB plumes, phenolic oxidation is expected to form nitroaromatics in high yield which can explain in part the BrC content of associated SOA. We conducted a set of experiments as part of the Monoterpene and Oxygenated aromatics Oxidation at Night and under LIGHTs (MOONLIGHT) campaign to evaluate the chemical and physical drivers of phenolic compound evolution in high nitrogen oxide (NOx = NO + NO2) wildfire plumes, specifically investigating the composition, volatility, and absorption of the SOA components formed under OH and NO3 oxidation, with catechol as the focus of this thesis. Oxidation products in both the gas and particle phases were measured using an I- adduct high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF I- CIMS) coupled with the Filter Inlet for Gases and Aerosols (FIGAERO). Oxidation of catechol produced BrC, defined by light absorption at 405 nm, at the highest yields out of all the phenolics studied. Particle-phase nitrocatechol (C6H5NO4) was found to account for 28% and 79% of organic aerosol (OA) mass formed from OH-initiated or NO3-initiated oxidation, respectively, and was strongly associated with BrC. Effective molar yields, i.e., including chemical and physical losses, of nitrocatechol were measured to range from 0.65 to 1 for NO3-initiated oxidation, and 0.03 for OH oxidation conditions. Maximum SOA mass yields from catechol oxidation were strongly tied to formation of nitrocatechol, ranging from 0.38 to 1.63 for the different experiments, lower than previously reported values. Higher SOA mass yields from catechol oxidation were found for NO3 rather than OH oxidation. The effective volatility of the SOA measured with the FIGAERO thermograms decreased significantly with subsequent aging after formation. Gas-particle partitioning measurements imply the saturation vapor concentration of nitrocatechol to be roughly 5 [micrograms] m-3, while the FIGAERO thermogram model estimate is lower but in the same order of magnitude, implying that wildfire gas-particle partitioning of nitroaromatics is likely dynamic. Group contribution method estimates of nitrocatechol saturation concentration range across 8 orders of magnitude with 3 [micrograms] m-3 from the Nannoolal method paired with the Joback and Reid boiling point method being closest to our observational estimates. In extended photochemical aging experiments, BrC formed from catechol oxidation had a photochemical lifetime of ~12 hours, while that of particulate nitrocatechol ranged from 7 hours if formed by NO3 oxidation to 18 hours if formed by OH oxidation. Implications for atmospheric evolution of BrC in wildfire and mechanisms of particulate nitroaromatic losses are discussed.
Book Synopsis Mechanisms of Atmospheric Oxidation of the Alkanes by : Jack G Calvert
Download or read book Mechanisms of Atmospheric Oxidation of the Alkanes written by Jack G Calvert and published by Oxford University Press. This book was released on 2008-09-15 with total page 1005 pages. Available in PDF, EPUB and Kindle. Book excerpt: An international team of eminent atmospheric scientists have prepared Mechanisms of Atmospheric Oxidation of the Alkanes as an authoritative source of information on the role of alkanes in the chemistry of the atmosphere. The book includes the properties of the alkanes and haloalkanes, as well as a comprehensive review and evaluation of the existing literature on the atmospheric chemistry of the alkanes and their major atmospheric oxidation products, and the various approaches now used to model the alkane atmospheric chemistry. Comprehensive coverage is given of both the unsubstituted alkanes and the many haloalkanes. All the existing quality measurements of the rate coefficients for the reactions of OH, Cl, O(3P), NO3, and O3 with the alkanes, the haloalkanes, and their major oxidation products have been reviewed and evaluated. The expert authors then give recommendations of the most reliable kinetic data. They also review the extensive literature on the mechanisms and rates and modes of photodecomposition of the haloalkanes and the products of atmospheric oxidation of the alkanes and the haloalkanes, and make recommendations for future use by atmospheric scientists. The evaluations presented allow an extrapolation of the existing kinetic and photochemical data to those alkanes and haloalkanes that are as yet unstudied. The current book should be of special interest and value to the modelers of atmospheric chemistry as a useful input for development of realistic modules designed to simulate the atmospheric chemistry of the alkanes, their major oxidation products, and their influence on ozone and other trace gases within the troposphere.
Book Synopsis Secondary Organic Aerosol Formation from Aromatic Hydrocarbons by : Chen Song
Download or read book Secondary Organic Aerosol Formation from Aromatic Hydrocarbons written by Chen Song and published by . This book was released on 2006 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
