Download or read book Heterogeneous and Multiphase Chemistry of Trace Atmospheric Gases with Mineral Dust and Other Metal Containing Particles written by Aruni Gankanda and published by . This book was released on 2016 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particulate matter in the atmosphere emitted from various natural and anthropogenic sources is important due to their effects on the chemical balance of the atmosphere, the Earth's climate, human health and biogeochemical cycles. Although there have been many studies performed to understand the above effects, there still remains substantial uncertainty associated with processes involved and thus it is difficult for current atmospheric chemistry and climate models to reconcile model results with field measurements. Therefore, it is important to have better agreement between models and observations as the accuracy of future atmospheric chemistry and climate predictions depends on it. In this research, a greater understanding of the role of mineral dust chemistry was pursued through focused laboratory studies in order to better understand fundamental processes involved. In particular, studies to further understand the photochemistry of adsorbed nitrate, an important inorganic ion associated with particulate matter exposed to gas-phase nitrogen oxides, were conducted using Al2O3, TiO2 and NaY zeolite to represent non-photoactive components, photoactive components and aluminosilicate respectively, present in mineral dust. These studies reveal that photochemistry of nitrate adsorbed on mineral dust is governed by wavelength of light, physicochemical properties of dust particles and adsorption mode of nitrate. Gas phase NO2, NO and N2O are the photolysis products of nitrate on oxide particles under dry conditions. In contrast, nitrate adsorbed on zeolite is converted mainly to adsorbed nitrite upon irradiation. This nitrite yield is decreased with increasing relative humidity. Gas phase N2O is the main photolysis product of nitrate adsorbed in zeolite in the presence of co-adsorbed ammonia. Water adsorbed on semiconducting TiO2 can be photochemically converted to hydroxyl radicals.
Download or read book Chemistry of Multiphase Atmospheric Systems written by Wolfgang Jaeschke and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 773 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapidly increasing interest in the problems of air pollution and source-receptor relationships has led to a significant expansion of knowledge in the field of atmospheric chemistry. In general the chemistry of atmospheric trace constituents is governed by the oxygen content of the atmosphere. Upon entering the atmosphere in a more or less reduced state, trace substances are oxidized via various pathways and the generated products are often precursors of acidic compounds. Beside oxidation processes occurring in the gas phase, gaseous compounds are often converted into solid aerosol particles. The various steps within gas-to-particle conversion are constantly interacting with condensation processes, which are caused by the tropospheric water content. Thus in addition to the gaseous state, a liquid and solid state exists within the troposphere. The solid phase consists of atmospheric conversion products or fly ash and mineral dust. The liquid phase consists of water, conversion products and soluble compounds. The chemistry occurring within this system is often referred to as hydrogeneous chemistry. The chemist interprets this term, however, more strictly as reactions which occur only at an interphase between phases. This, however, is not always what happens in the atmosphere. There are indeed heterogeneous processes such as reactions occurring on the surface of dry aerosol particles. But apart from these, we must focus as well on reactions in the homogeneous phase, which are single steps of consecutive reactions running through various phases.
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 Heterogeneous Atmospheric Chemistry written by David R. Schryer and published by American Geophysical Union. This book was released on 1982 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 26. In the past few years it has become increasingly clear that heterogeneous, or multiphase, processes play an important role in the atmosphere. Unfortunately the literature on the subject, although now fairly extensive, is still rather dispersed. Furthermore, much of the expertise regarding heterogeneous processes lies in fields not directly related to atmospheric science. Therefore, it seemed desirable to bring together for an exchange of ideas, information, and methodologies the various atmospheric scientists who are actively studying heterogeneous processes as well as other researchers studying similar processes in the context of other fields.
Download or read book The Heterogeneous Chemistry of Mineral Dust and Sea Salt and Their Components with Trace Atmospheric Gases written by Brenda Jean Krueger and published by . This book was released on 2005 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heterogeneous Chemistry of Atmospheric Mineral Dust Particles and Their Resulting Cloud nucleation Properties written by Ryan Christopher Sullivan and published by . This book was released on 2008 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mineral dust particles are a major component of tropospheric aerosol mass and affect regional and global atmospheric chemistry and climate. Dust particles experience heterogeneous reactions with atmospheric gases that alter the gas and particle-phase chemistry. These in turn influence the warm and cold cloud nucleation ability and optical properties of the dust particles. This dissertation investigates the atmospheric chemistry of mineral dust particles and their role in warm cloud nucleation through a combination of synergistic field measurements, laboratory experiments, and theoretical modeling. In-situ measurements made with a single-particle mass spectrometer during the ACE-Asia field campaign in 2001 provide the motivation for this work. The observed mixing state of the individual ambient particles with secondary organic and inorganic components is described in Chapter 2. A large Asian dust storm occurred during the campaign and produced dramatic changes in the aerosol's composition and mixing state. The effect of particle size and mineralogy on the atmospheric processing of individual dust particles is explored in Chapters 3 & 4. Sulfate was found to accumulate preferentially in submicron iron and aluminosilicate-rich dust particles, while nitrate and chloride were enriched in supermicron calcite-rich dust. The mineral dust (and sea salt particles) were also enriched in oxalic acid, the dominant component of water soluble organic carbon. Chapter 5 explores the roles of gas-phase photochemistry and partitioning of the diacids to the alkaline particles in producing this unique behavior. The effect of the dust's mixing state with secondary organic and inorganic components on the dust particles' solubility, hygroscopicity, and thus warm cloud nucleation properties is explored experimentally and theoretically in Chapter 6. Cloud condensation nucleation (CCN) activation curves revealed that while calcium nitrate and calcium chloride particles were very hygroscopic and CCN-active, due to the high solubility of these compounds, calcium sulfate and calcium oxalate were not. Particles composed of these two sparingly soluble compounds had apparent hygroscopicities similar to pure calcium carbonate. This implies that the commonly made assumption that all dust particles become more hygroscopic after atmospheric processing must be revisited. Calcium sulfate and oxalate represent two forms of aged mineral dust particles that remain non-hygroscopic and thus have poor CCN nucleation ability. The particle generation method (dry versus wet) was found to significantly affect the chemistry and hygroscopicity of the aerosolized particles. Finally, in Chapter 7 the timescale for the atmospheric conversion of insoluble calcite particles to soluble, CCN-active calcium nitrate particles was derived from aerosol flow tube experiments. The reaction rate is rapid was used to estimate the conversion of calcite particles to very hygroscopic particles can occur in just a few hours of exposure to tropospheric levels of nitric acid. This process will therefore be controlled by the availability of nitric acid and its precursors, as opposed to the available atmospheric reaction time.
Download or read book Advances In Atmospheric Chemistry Volume 2 Organic Oxidation And Multiphase Chemistry written by John R Barker and published by World Scientific. This book was released on 2019-01-07 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This series presents authoritative invited summaries of research on atmospheric chemistry in a changing world. These range from comprehensive reviews of major subject areas to focused accounts by individual research groups. The topics may include laboratory studies, field measurements, in situ monitoring and remote sensing, studies of composition, chemical modeling, theories of atmospheric chemistry and climate, feedback mechanisms, emissions and deposition, biogeochemical cycles, and the links between atmospheric chemistry and the climate system at large.Volume 2 comprises chapters describing research on multiphase chemistry affecting air quality in China, on multiphase chemistry of organic compounds leading to secondary organic aerosol formation, on biogeochemical cycles involving ammonia, on oxidation of aromatic compounds, on reactions of Criegee intermediates (important in oxidation of alkenes), and on laboratory and field measurements of isotopic fractionation in the atmosphere.
Download or read book Understanding Atmospheric Mineral Dust Photochemistry written by Milena Ponczek and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Minerals that absorb light near UV/Vis present in dust aerosols interact with trace gases in the atmosphere and can initiate a new and potentially significant photo-induced heterogeneous chemistry, which is currently poorly documented. This thesis aims to address different issues of mineral dust reactivity towards organic compounds and, therefore, assesses the impact of these interactions on several aspects of atmospheric sciences. We investigated experimentally the physicochemical interaction of mineral aerosols (synthetic and natural), pure or coated with organic/inorganic materials with trace gases from several chemical families (alcohols, ketones, carboxylic acids, etc.), under simulated conditions close to the real environment (regarding to humidity, concentration in the gas phase, wavelength and intensity of irradiation, pressure and temperature). In a first approach, we studied the uptake of oxygenated organics onto different dust proxies such as SiO2, TiO2 and Arizona test dust (ATD) evaluating the effects of ambient conditions on the uptake kinetics and product generation. Then, we discussed the chemistry of 5 dicarboxylic acids (C4-C8) on ATD particles upon UV-A irradiation monitoring products in the gas phase as well as those whose stay adsorbed on the particulate phase. Lastly, we investigated the influence of nitrate anions on the uptake of acetone on ATD and SiO2 and in the photochemical product formation of glutaric acid on ATD. Overall, our results clearly show that photochemical processing of dust aerosols should be considered as a source of reactive compounds and as a key process affecting their action as ice nucleation and cloud condensation nuclei.
Download or read book Ocean Atmosphere Interactions of Gases and Particles written by Peter S. Liss and published by Springer. This book was released on 2013-12-18 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceans and atmosphere interact through various processes, including the transfer of momentum, heat, gases and particles. In this book leading international experts come together to provide a state-of-the-art account of these exchanges and their role in the Earth-system, with particular focus on gases and particles. Chapters in the book cover: i) the ocean-atmosphere exchange of short-lived trace gases; ii) mechanisms and models of interfacial exchange (including transfer velocity parameterisations); iii) ocean-atmosphere exchange of the greenhouse gases carbon dioxide, methane and nitrous oxide; iv) ocean atmosphere exchange of particles and v) current and future data collection and synthesis efforts. The scope of the book extends to the biogeochemical responses to emitted / deposited material and interactions and feedbacks in the wider Earth-system context. This work constitutes a highly detailed synthesis and reference; of interest to higher-level university students (Masters, PhD) and researchers in ocean-atmosphere interactions and related fields (Earth-system science, marine / atmospheric biogeochemistry / climate). Production of this book was supported and funded by the EU COST Action 735 and coordinated by the International SOLAS (Surface Ocean- Lower Atmosphere Study) project office.
Download or read book Atmospheric Chemistry written by E. Mészáros and published by Elsevier. This book was released on 1981-10-01 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric Chemistry
Download or read book Chemical Compounds in The Atmosphere written by T Graedel and published by Elsevier. This book was released on 2012-12-02 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical Compounds in the Atmosphere deals with the chemistry of organic and inorganic compounds found in the atmosphere, including rare gases and compounds of oxygen and hydrogen, halogenated aromatic compounds, and organometallic compounds. The sources and concentrations of atmospheric trace gases are discussed, along with their chemical reactions and ultimate fates. The compounds are divided into groups on the basis of chemical constituent or chemical structure. Comprised of 10 chapters, this book opens with an overview of atmospheric composition and atmospheric chemistry, followed by a discussion on inorganic compounds present in the troposphere such as rare gases and compounds containing nitrogen, sulfur, and halogens. The next chapters focus on hydrocarbons such as alkanes, alkenes, and alkynes; carbonyl compounds such as ketones and aldehydes; oxygenated and nitrogen- and sulfur-containing organic compounds; organic halogenated compounds such as mercaptans and thiocyanates; and organometallic compounds such as organophosphorus pesticides. The final chapter is a synthesis of data on atmospheric compounds mentioned in this text, with emphasis on their occurrence, sources, oxidation, and lifetimes. The chemistry of acid rain is also considered. This monograph will be of value to those engaged in atmospheric measurements, theoretical and laboratory studies of chemical parameters relevant to the atmosphere, and air quality assessments.
Download or read book Global Atmospheric Biospheric Chemistry written by Ronald G. Prinn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the invited papers and a transcript of the final panel discussion in the First Scientific Conference of the International Global Atmospheric Chemistry (lGAC) Project, held in Eilat, Israel from April 18-22, 1993. The conference was hosted by the Israeli Institute for Biological Research (IIBR) and was the 37th in the prestigious OHOLO Conference series in Israel. The conference was devoted to the subject of "Global Atmospheric-Biospheric Chemistry" and was a landmark event in this area. It provided the first comprehensive report of progress under IGAC toward improving our understanding of the chemical and biological processes that determine the changing composition of the earth's atmosphere. This work is an essential component of the comprehensive International Geosphere Biosphere Program (lGBP) devoted to measuring and understanding global changes in the past and present, and predicting the future evolution of our planet. I want to devote this brief foreword to thanking several people who worked especially hard to make the conference a success and who helped to produce this volume as a record of the event. Paul Crutzen, Amram Golombek, Pamela Matson and Henning Rodhe did sterling service on the conference organizing committee. Special thanks go to Amram Golombek and Dr. Cohen, the Director of IIBR, who hosted the event in Israel. Anne Slinn did an excellent job in producing the Abstract book and helping with administrative matters. Alex Pszenny helped capably to critically review the Abstracts.
Download or read book Chemistry of the Natural Atmosphere written by Warneck and published by Academic Press. This book was released on 1988-03-01 with total page 773 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemistry of the Natural Atmosphere
Download or read book Aeolian Dust and Dust Deposits written by Kenneth Pye and published by Elsevier. This book was released on 2015-07-14 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aeolian Dust and Dust Deposits explores the entrainment, dispersion, and deposition of aeolian dust and dust deposits, with emphasis on transport and deposition of dust derived by deflation of surface sediments and soils. Topics covered range from the mechanisms of fine-particle formation to dust sources, sinks, and rates of deposition. Dust-transporting wind systems are also discussed, along with the grain size, mineralogy, and chemical composition of aeolian dust. Comprised of nine chapters, this book begins with an overview of the general nature and significance of windborne dust as well as the importance of aeolian dust and loess. The next chapter deals with the mechanisms underlying the formation of fine particles, including glacial grinding, frost and salt weathering, and fluvial comminution. The reader is then introduced to dust entrainment, transport, and deposition, together with dust sources, sinks, and rates of deposition. Subsequent chapters focus on the implications of dust deflation, transport, and deposition; dust deposition in the oceans; and loess distribution and the thickness and morphology of loess deposits. This monograph is written primarily for research workers and advanced students in sedimentology, geomorphology, and Quaternary studies, but is also likely to be of value to soil scientists, meteorologists, planetary geologists, engineers, and others concerned with environmental management.
Download or read book Atmospheric Chemical Compounds written by T. E. Graedel and published by Elsevier. This book was released on 2012-12-02 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: This practical reference examines the structure and properties of the atmosphere, including listings of compounds in clouds, fog, rain, snow, and ice; a listing of compounds detected in the stratosphere; and a compendium of compounds in indoor air. An introduction to carcinogenicity and bioassay of atmospheric compounds is also presented. Readers will find the extensive cross-referencing especially useful--compounds can be located by chemical type, name, CAS registry number, or source.
Download or read book Processing of Trace Metals in Atmospheric Particulate Matter written by Aurelie Rose Marcotte and published by . This book was released on 2015 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particulate trace metals can enter the atmosphere as mineral dust, sea spray, anthropogenic emissions, biomass burning, etc. Once in the atmosphere they can undergo a variety of transformations including aqueous phase (cloud) processing, photochemical reactions, interact with gases, and ultimately deposit. Metals in aerosols are of particular interest because of their natural and anthropogenic sources as well as their effects on local (human health) and global (climate change) scales. This work investigates the metal component of atmospheric particles and how it changes during physical and chemical processes at local, regional and global scales, through laboratory and field studies. In the first part of this work, the impact of local dust storms (haboobs) on ambient metal concentrations and speciation is investigated in Tempe, AZ. It was found that metal concentrations substantially increase (> 10 times) during these events before returning to pre-storm levels. In a second part of this work, the impact of fog processing on metal concentrations, solubility and speciation is examined through field observations in California's Central Valley. The observations show that fog processing has a profound effect on local metal concentrations but the trends are not consistent between sites or even between events, indicating complex processes that need further investigation. For example, fogs have an effect on scavenging and solubility of iron in Davis, while in Fresno soluble iron content is indicative of the source of the aerosol. The last part of the thesis investigates the role of particle size on the solubilization of iron from mineral dust aerosols during global atmospheric transport through laboratory experiments. The experiments showed that mineralogy and pH have the greatest effect on iron solubility in atmospheric aerosols in general while particle size and photochemistry impact mainly the solubility of iron oxides.
Download or read book Progress And Problems In Atmospheric Chemistry written by John R Barker and published by World Scientific. This book was released on 1995-12-26 with total page 954 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric chemistry is central to understanding global changes — ozone depletion, appearance of the polar ozone holes, and compositional changes which worsen the greenhouse effect. Because of its importance, work is progressing on many fronts.This volume emphasizes the troposhere and stratosphere and has chapters on gas phase, condensed phase, and heterogeneous chemistry. Present progress is emphasized, and important future directions are also described.This book fills a need not satisfied by any others and will be popular for some years to come. It informs students and newcomers to the field of the many facets of atmospheric chemistry and can be used as a text for advanced students. It is also a valuable desk reference summarizing activities by quite a number of the most active research groups.Chapter 18 by Kolb et al. on heterogeneous chemistry is especially noteworthy because it represents a unique joint effort by several groups working on a very timely subject; they describe a conceptual framework and establish conventions which will be standard in future papers on this subject.
