Characterization of Atmospheric Aerosols in Kathmandu, New Hampshire, and Texas: Carbonaceous, Isotopic, and Water-soluble Organic Composition

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dc.contributor.advisorGriffin, Robert J.
dc.creatorShakya, Kabindra Man
dc.date.accessioned2013-03-08T00:38:50Z
dc.date.available2013-03-08T00:38:50Z
dc.date.issued2011
dc.description.abstractTo improve the understanding of aerosol composition, sources, and spatial and temporal variations, atmospheric aerosols were characterized in three locations. Ambient aerosols were characterized using 24-hour samples collected from Kathmandu, Nepal (urban), New Hampshire (semi-rural) and Houston (urban). Results are reported in the main chapters. Chamber studies of secondary organic aerosols (SOA) formation from polycyclic aromatic hydrocarbons (PAHs) and the effects of in-situ SOA formation on atmospheric mercury oxidation are described in the appendices. Carbonaceous, ionic, and isotopic species in aerosols from Kathmandu identified local primary emissions, most likely vehicular exhaust as the most important aerosol sources. Carbonaceous aerosols collected in Kathmandu (24.5 μg C m -3 ) were much larger than those in New Hampshire (3.74 μg C m -3 ) during winter. Stable carbon isotope in aerosols of Kathmandu and New Hampshire were similar (Δδ 13 C ∠ 0.5[per thousand]) while stable nitrogen isotope were much lower in aerosols of Kathmandu (Δδ 15 N = 8.3[per thousand]). Aerosols in New Hampshire exhibited a large seasonal variation for carbonaceous aerosols, stable nitrogen isotope, and the aromatic fraction of water-soluble organic carbon (WSOC). Pure aliphatics (H-C) were the dominant functional group in WSOC. Results illustrate the importance of secondary aerosol sources throughout the year, with enhanced importance of primary sources during winter. Stable carbon isotope values suggest a consistent isotopic signature of carbonaceous aerosol sources, while the nitrogen isotope values indicate the variable nitrogenous sources and the strong influence of meteorological parameters (temperature and relative humidity) on nitrogen isotope fractionation. Characteristics of methoxyphenols (lignin macropolymers) in the ambient aerosols are reported for the first time using CuO oxidation method. The study illustrates the use of lignin oxidation products (LOPs) in aerosols as potential tracers of primary biological aerosol particles (PBAP). The methoxyphenols identified soil organic matter and altered woody angiosperms, with minor influence from soft tissues and gymnosperms as the important PBAP sources in mainly coarse particles in Houston atmosphere. Solvent-extracted methoxyphenols (lignin monomers) and anhydrosugars (levoglucosan, mannosan, and galactosan) in aerosols were either absent or very small, suggesting very limited biomass burning influence with any trace-level presence originating from long-range transport.
dc.format.extent290 p.en_US
dc.format.mimetypeapplication/pdf
dc.identifier.callnoTHESIS C.E. 2011 SHAKYA
dc.identifier.citationShakya, Kabindra Man. "Characterization of Atmospheric Aerosols in Kathmandu, New Hampshire, and Texas: Carbonaceous, Isotopic, and Water-soluble Organic Composition." (2011) Diss., Rice University. <a href="https://hdl.handle.net/1911/70440">https://hdl.handle.net/1911/70440</a>.
dc.identifier.digitalShakyaKen_US
dc.identifier.urihttps://hdl.handle.net/1911/70440
dc.language.isoeng
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.
dc.subjectHealth sciences
dc.subjectEnvironmental science
dc.subjectApplied sciences
dc.subjectEarth sciences
dc.subjectAtmospheric aerosols
dc.subjectSecondary organic aerosols
dc.subjectFunctional groups
dc.subjectCarbonaceous aerosols
dc.subjectAtmospheric chemistry
dc.subjectEnvironmental engineering
dc.titleCharacterization of Atmospheric Aerosols in Kathmandu, New Hampshire, and Texas: Carbonaceous, Isotopic, and Water-soluble Organic Composition
dc.typeThesis
dc.type.materialText
thesis.degree.departmentChemical and Biomolecular Engineering
thesis.degree.disciplineEngineering
thesis.degree.grantorRice University
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy
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