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Photochemical Reactivity of Dissolved Organic Matter: Implications for the Environmental Fate and Engineered Removal of Saxitoxins
Photochemical Reactivity of Dissolved Organic Matter: Implications for the Environmental Fate and Engineered Removal of Saxitoxins
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202103110
- ISBN
- 9798315702337
- DDC
- 628
- 서명/저자
- Photochemical Reactivity of Dissolved Organic Matter: Implications for the Environmental Fate and Engineered Removal of Saxitoxins
- 발행사항
- [Sl] : University of Colorado at Boulder, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 170 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-11, Section: B.
- 주기사항
- Advisor: Rosario-Ortiz, Fernando.
- 학위논문주기
- Thesis (Ph.D.)--University of Colorado at Boulder, 2025.
- 초록/해제
- 요약Dissolved organic matter (DOM) is a fundamental component of natural aquatic systems that influences processes such as nutrient cycling, primary productivity through the attenuation of light, indirect photochemical transformations of contaminants, and production of CO2 through photomineralization. DOM also has a major impact on engineered water treatment systems due to its reactivity with oxidants, such as chlorine and ozone, and absorption of ultraviolet (UV) light. Despite many years of efforts to characterize DOM, its complexity and variation across aquatic systems have imposed challenges to analyzing DOM composition, chemical structure, and reactivity. Two areas of DOM research that have remained unclear are its three-dimensional (3D) structure and its photochemical production of reactive intermediates (RIs). First, the 3D structure of DOM is important to understanding intermolecular interactions within DOM, the reactivity of DOM in engineered systems, and the interactions between DOM molecules and contaminants. Second, the photochemical production of RIs from DOM is well-understood, apart from hydroxyl radicals (•OH). Due to the fast reaction rates and non-selective reactivity of •OH, it is important to understand which chemical components of DOM contribute to •OH generation and how quickly •OH is formed.The RIs produced by DOM play a crucial role in the environmental fate of molecules such as saxitoxins, which do not absorb light in the solar spectrum and are resistant to microbial degradation and hydrolysis. Saxitoxins are a class of neurotoxins produced by cyanobacteria during a harmful algal bloom (HAB). The release of saxitoxins by cyanobacteria is a concern for the health of aquatic ecosystems, may cause human intoxication through recreation in affected water bodies, and threaten drinking water quality. Since saxitoxins are resistant to degradation through several conventional water treatment methods, it is critical to develop an efficient removal option in the case that saxitoxins are present at dangerous levels in source waters. This thesis aims to address DOM structure and mechanisms of •OH production in order to elucidate its critical role in the photochemical degradation of emerging contaminants such as saxitoxins. Chapter 2 explores previous literature related to the 3D structure of DOM and proposes a new model to depict the simultaneous solubility of DOM molecules and their complex intermolecular interactions. In Chapter 3, the mechanism of the photochemical generation of •OH by DOM model photosensitizers is examined. Chapters 4 and 5 evaluate the indirect photochemical degradation of saxitoxins in natural surface waters and UV-advanced oxidation processes (AOP), respectively.
- 일반주제명
- Biological oceanography
- 기타저자
- University of Colorado at Boulder Civil Environmental and Architectural Engineering
- 기본자료저록
- Dissertations Abstracts International. 86-11B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■020 ▼a9798315702337
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■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a628
■1001 ▼aNorris, Kari Elena.▼0(orcid)0000-0002-6801-2134
■24510▼aPhotochemical Reactivity of Dissolved Organic Matter: Implications for the Environmental Fate and Engineered Removal of Saxitoxins
■260 ▼a[Sl]▼bUniversity of Colorado at Boulder▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a170 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-11, Section: B.
■500 ▼aAdvisor: Rosario-Ortiz, Fernando.
■5021 ▼aThesis (Ph.D.)--University of Colorado at Boulder, 2025.
■520 ▼aDissolved organic matter (DOM) is a fundamental component of natural aquatic systems that influences processes such as nutrient cycling, primary productivity through the attenuation of light, indirect photochemical transformations of contaminants, and production of CO2 through photomineralization. DOM also has a major impact on engineered water treatment systems due to its reactivity with oxidants, such as chlorine and ozone, and absorption of ultraviolet (UV) light. Despite many years of efforts to characterize DOM, its complexity and variation across aquatic systems have imposed challenges to analyzing DOM composition, chemical structure, and reactivity. Two areas of DOM research that have remained unclear are its three-dimensional (3D) structure and its photochemical production of reactive intermediates (RIs). First, the 3D structure of DOM is important to understanding intermolecular interactions within DOM, the reactivity of DOM in engineered systems, and the interactions between DOM molecules and contaminants. Second, the photochemical production of RIs from DOM is well-understood, apart from hydroxyl radicals (•OH). Due to the fast reaction rates and non-selective reactivity of •OH, it is important to understand which chemical components of DOM contribute to •OH generation and how quickly •OH is formed.The RIs produced by DOM play a crucial role in the environmental fate of molecules such as saxitoxins, which do not absorb light in the solar spectrum and are resistant to microbial degradation and hydrolysis. Saxitoxins are a class of neurotoxins produced by cyanobacteria during a harmful algal bloom (HAB). The release of saxitoxins by cyanobacteria is a concern for the health of aquatic ecosystems, may cause human intoxication through recreation in affected water bodies, and threaten drinking water quality. Since saxitoxins are resistant to degradation through several conventional water treatment methods, it is critical to develop an efficient removal option in the case that saxitoxins are present at dangerous levels in source waters. This thesis aims to address DOM structure and mechanisms of •OH production in order to elucidate its critical role in the photochemical degradation of emerging contaminants such as saxitoxins. Chapter 2 explores previous literature related to the 3D structure of DOM and proposes a new model to depict the simultaneous solubility of DOM molecules and their complex intermolecular interactions. In Chapter 3, the mechanism of the photochemical generation of •OH by DOM model photosensitizers is examined. Chapters 4 and 5 evaluate the indirect photochemical degradation of saxitoxins in natural surface waters and UV-advanced oxidation processes (AOP), respectively.
■590 ▼aSchool code: 0051.
■650 4▼aEnvironmental engineering
■650 4▼aBiological oceanography
■653 ▼aNatural aquatic systems
■653 ▼aDissolved organic matter
■653 ▼aHarmful algal bloom
■690 ▼a0775
■690 ▼a0416
■690 ▼a0474
■71020▼aUniversity of Colorado at Boulder▼bCivil, Environmental, and Architectural Engineering.
■7730 ▼tDissertations Abstracts International▼g86-11B.
■790 ▼a0051
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17356976▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
