자료유형  

 학위논문

Control Number  

0017164174

International Standard Book Number  

9798384438410

Dewey Decimal Classification Number  

543

Main Entry-Personal Name  

Dalton, Evan Zachary.

Publication, Distribution, etc. (Imprint  

[S.l.] : Indiana University., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

436 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-03, Section: B.

General Note  

Advisor: Raff, Jonathan.

Dissertation Note  

Thesis (Ph.D.)--Indiana University, 2024.

Summary, Etc.  

요약Nitrate (NO3ˉ) is ubiquitous in environmental systems, originating in part from the oxidation of nitrogen dioxide (NO2) in the atmosphere. Aerosols and surfaces accumulate NO3ˉ from nitric acid (HNO3) deposition, especially in polluted environments with high NOx (= NO2 + NO) concentrations originating from combustion. During the daytime, adsorbed NO3ˉ photolyzes to form NO2, hydroxyl radical (OH), nitrous acid (HONO), and oxygen atoms, all of which react with compounds on environmental surfaces where they impact atmospheric composition. This chemistry is poorly understood, leading to large uncertainties in atmospheric chemistry models used to inform air pollution policy. This dissertation aims to improve our understanding of environmental NO3ˉ photochemistry, which is a significant heterogenous source of reactive species that affects daytime ozone pollution and the ability of the atmosphere to remove pollutants.Experiments focused on elucidating the chemistry of NO3ˉ photoproducts in the presence of chloride or organic matter containing aliphatic and chromophoric (i.e. light absorbing) components. Aliphatic organic matter scavenges OH and produces superoxide, which subsequently converts NO2 to HONO. Chromophoric organic matter is both a source and sink of many radical intermediates. Specifically, light absorbing components of organic matter act as electron mediators that regulate ambient concentrations of reactive oxygen and nitrogen species. Lastly, this work showed that nitrate present in sea salt aerosol is a source of reactive Cl species such as Cl2, HOCl, and ClNO2. Product amounts were highly dependent on pH, with highest concentrations formed below pH 7. Oxygen atom, formed as a product of nitrate photolysis, was found to be an important oxidant for chloride, although this chemistry is not considered in most models. Overall, this research advances our understanding of nitrate photolysis mechanisms within complex matrices, establishing a foundation for the future parameterization of nitrate photochemistry for atmospheric models.

Subject Added Entry-Topical Term  

Analytical chemistry.

Subject Added Entry-Topical Term  

Environmental science.

Subject Added Entry-Topical Term  

Atmospheric chemistry.

Index Term-Uncontrolled  

Chlorine

Index Term-Uncontrolled  

Kinetic modeling

Index Term-Uncontrolled  

Nitrate

Index Term-Uncontrolled  

Photochemistry

Index Term-Uncontrolled  

Reactive emissions

Added Entry-Corporate Name  

Indiana University Chemistry

Host Item Entry  

Dissertations Abstracts International. 86-03B.

Electronic Location and Access  

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Control Number  

joongbu:658626