Download or read book Formation of Secondary Aerosols Under Photolysis written by Chris Canfield and published by . This book was released on 2002 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various studies have researched secondary aerosols to determine the source contributions and environmental parameters contributing to the aerosol and Particulate Matter (PM) 10 loading in the ambient air. The majority of studies abroad consider organic contributions to aerosol loading. Concentrations of ammonia, nitrogen dioxide, and sulfur dioxide present in the air have been confirmed to have an effect on the formation of secondary aerosols in the atmosphere. This thesis studies the effects of nitrogen dioxide, sulfur dioxide, ammonia, and humidity in the air on the formation of secondary aerosols in a photo reactor operating at 340 nm.
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.
Download or read book Effects of Humidity on the Formation of Secondary Aerosols in a Photolytic SO2 NO2 System written by Sharon Kay Gillaspy and published by . This book was released on 1981 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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:
Download or read book Atmospheric Aerosols written by Claudio Tomasi and published by John Wiley & Sons. This book was released on 2017-03-20 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ein Blick auf die morphologischen, physikalischen und chemischen Eigenschaften von Aerosolen aus den unterschiedlichsten natürlichen und anthropogenen Quellen trägt zum besseren Verständnis der Rolle bei, die Aerosolpartikel bei der Streuung und Absorption kurz- und langwelliger Strahlung spielen. Dieses Fachbuch bietet Informationen, die sonst schwer zu finden sind, und vermittelt ausführlich die Kenntnisse, die erforderlich sind, um die mikrophysikalischen, chemischen und Strahlungsparameter zu charakterisieren, die bei der Wechselwirkung von Sonnen- und Erdstrahlen so überaus wichtig sind. Besonderes Augenmerk liegt auf den indirekten Auswirkungen von Aerosolen auf das Klima im Rahmen des komplexen Systems aus Aerosolen, Wolken und der Atmosphäre. Auch geht es vorrangig um die Wirkungen natürlicher und anthropogener Aerosole auf die Luftqualität und die Umwelt, auf die menschliche Gesundheit und unser kulturelles Erbe. Mit einem durchgängig lösungsorientierten Ansatz werden nicht nur die Probleme und Gefahren dieser Aerosole behandelt, sondern auch praktikable Lösungswege aufgezeigt.
Download or read book Introduction to Atmospheric Chemistry written by Daniel J. Jacob and published by Princeton University Press. This book was released on 1999 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric chemistry is one of the fastest growing fields in the earth sciences. Until now, however, there has been no book designed to help students capture the essence of the subject in a brief course of study. Daniel Jacob, a leading researcher and teacher in the field, addresses that problem by presenting the first textbook on atmospheric chemistry for a one-semester course. Based on the approach he developed in his class at Harvard, Jacob introduces students in clear and concise chapters to the fundamentals as well as the latest ideas and findings in the field. Jacob's aim is to show students how to use basic principles of physics and chemistry to describe a complex system such as the atmosphere. He also seeks to give students an overview of the current state of research and the work that led to this point. Jacob begins with atmospheric structure, design of simple models, atmospheric transport, and the continuity equation, and continues with geochemical cycles, the greenhouse effect, aerosols, stratospheric ozone, the oxidizing power of the atmosphere, smog, and acid rain. Each chapter concludes with a problem set based on recent scientific literature. This is a novel approach to problem-set writing, and one that successfully introduces students to the prevailing issues. This is a major contribution to a growing area of study and will be welcomed enthusiastically by students and teachers alike.
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.
Download or read book Atmospheric Aerosol Chemistry written by Hind A. Al-Abadleh and published by Walter de Gruyter GmbH & Co KG. This book was released on 2022-04-19 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols are an important and a highly complex component of the Earth’s atmosphere that alter the radiative forcing and the chemical composition of the gas phase. These effects have impacts on local air quality and the global climate. Atmospheric Aerosol Chemistry outlines research findings to date in aerosol chemistry and advances in analytical tools used in laboratory settings for studying their surface and bulk reactivity.
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.
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:
Download or read book Secondary Organic Aerosol SOA Formation from Aqueous OH Radical Oxidation of Dicarbonyl Compounds in the Atmosphere written by Yi Tan and published by . This book was released on 2010 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: Secondary organic aerosols (SOA) affect visibility, health and global climate. Current chemical transport models cannot represent SOA in the free troposphere. Fog/cloud processing, which is the dominant source of atmospheric sulfate, has been recognized as a missing source of SOA globally. Aqueous photooxidation of water-soluble products (e.g., glyoxal and methylglyoxal) of gas-phase photochemistry yields low-volatility compounds including oxalic acid. When this chemistry takes place in clouds and fogs followed by droplet evaporation (or if this chemistry occurs in aerosol water) then products remain in part in the particle phase, forming SOA. However, current aqueous SOA formation mechanism has not shown how the starting concentrations of precursors and presence of acidic sulfate affect product formation. Aqueous phase photochemical batch reactions were conducted with glyoxal and methylglyoxal at cloud relevant concentrations, using hydrogen peroxide photolysis as the hydroxyl radical (OH) source. Experiments were repeated at higher concentrations and with/without sulfuric acid. Precursors and products were investigated using ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS), and IC-ESI-MS. Products included carboxylic acids and higher molecular weight compounds, which are major constituents of aerosols. Sulfuric acid shows little effect on product formation. Dilute aqueous chemistry models successfully reproduced product formation for glyoxal and methylglyoxal at cloud relevant conditions, but measurements deviated from predictions from predictions at elevated concentrations. Higher molecular weight products become increasingly important as precursor concentration increases. Aqueous radical-radical reactions provide explanations for observed higher molecular weight products. Additionally, acetic acid is identified as an SOA precursor for the first time. This work provides an improved understanding of aqueous phase dicarbonyl oxidation mechanism and the overall significance of aqueous SOA formation. Kinetic data are made available to regional and global atmospheric models, and the mechanism described in this work will help people to mitigate adverse aerosol effects.
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:
Download or read book Chemistry of Secondary Organic Aerosol Formation from Reactions of Alkenes with Ozone and Nitrate Radicals written by Huiming Gong and published by . This book was released on 2003 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanisms of Formation of Secondary Organic Aerosols and Implications for Global Radiative Forcing written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic material constitutes about 50% of global atmospheric aerosol mass, and the dominant source of organic aerosol is the oxidation of volatile hydrocarbons, to produce secondary organic aerosol (SOA). Understanding the formation of SOA is crucial to predicting present and future climate effects of atmospheric aerosols. The goal of this program is to significantly increase our understanding of secondary organic aerosol (SOA) formation in the atmosphere. Ambient measurements indicate that the amount of SOA in the atmosphere exceeds that predicted in current models based on existing laboratory chamber data. This would suggest that either the SOA yields measured in laboratory chambers are understated or that all major organic precursors have not been identified. In this research program we are systematically exploring these possibilities.
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.
Download or read book Atmospheric Chemistry and Physics written by John H. Seinfeld and published by John Wiley & Sons. This book was released on 2012-12-18 with total page 1249 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thoroughly restructured and updated with new findings and new features The Second Edition of this internationally acclaimed text presents the latest developments in atmospheric science. It continues to be the premier text for both a rigorous and a complete treatment of the chemistry of the atmosphere, covering such pivotal topics as: * Chemistry of the stratosphere and troposphere * Formation, growth, dynamics, and properties of aerosols * Meteorology of air pollution * Transport, diffusion, and removal of species in the atmosphere * Formation and chemistry of clouds * Interaction of atmospheric chemistry and climate * Radiative and climatic effects of gases and particles * Formulation of mathematical chemical/transport models of the atmosphere All chapters develop results based on fundamental principles, enabling the reader to build a solid understanding of the science underlying atmospheric processes. Among the new material are three new chapters: Atmospheric Radiation and Photochemistry, General Circulation of the Atmosphere, and Global Cycles. In addition, the chapters Stratospheric Chemistry, Tropospheric Chemistry, and Organic Atmospheric Aerosols have been rewritten to reflect the latest findings. Readers familiar with the First Edition will discover a text with new structures and new features that greatly aid learning. Many examples are set off in the text to help readers work through the application of concepts. Advanced material has been moved to appendices. Finally, many new problems, coded by degree of difficulty, have been added. A solutions manual is available. Thoroughly updated and restructured, the Second Edition of Atmospheric Chemistry and Physics is an ideal textbook for upper-level undergraduate and graduate students, as well as a reference for researchers in environmental engineering, meteorology, chemistry, and the atmospheric sciences. Click here to Download the Solutions Manual for Academic Adopters: http://www.wiley.com/WileyCDA/Section/id-292291.html
Download or read book Formation of Secondary Organic Aerosols in Atmospheric Liquid Water written by Marwa M. H. El-Sayed and published by . This book was released on 2018 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of secondary organic aerosols through aqueous processes (aqSOA) has been identified as an important route in forming organic aerosols; however, many aspects of this formation are still uncertain. One main uncertainty is the nature by which these aqueous compounds are formed, whether the formation is reversible, irreversible, or a mixture of both. To date, there are no ambient measurements to quantify or constrain the relative contributions of reversible/irreversible aqSOA. Hence, we have developed an online method to simultaneously measure water-soluble organic carbon in the gas (WSOCg) and particle (WSOCp) phases to characterize the reversible and irreversible uptake of water-soluble organic gases to aerosol liquid water (ALW) across the different seasons in Maryland located in the eastern United States.
