Environmental Chemistry Commons^™

Nitrate Radicals And Biogenic Volatile Organic Compounds: Oxidation, Mechanisms And Organic Aerosol, Nga Lee Ng, Steven S. Brown, Alexander T. Archibald, Elliot Atlas, Ronald C. Cohen, John N. Crowley, Douglas A. Day, Neil M. Donahue, Juliane L. Fry, Hendrik Fuchs, Robert J. Griffin, Marcelo I. Guzman, Hartmut Hermann, Alma Hodzic, Yoshiteru Iinuma, José L. Jimenez, Astrid Kiendler-Scharr, Ben H. Lee, Deborah J. Luecken, Jingqiu Mao, Robert Mclaren, Anke Mutzel, Hans D. Osthoff, Bin Ouyang, Benedicte Picquet-Varrault, Ulrich Platt, Havala O. T. Pye, Yinon Rudich, Rebecca H. Schwantes, Manabu Shiraiwa, Jochen Stutz, Joel A. Thornton, Andreas Tilgner, Brent J. Williams, Rahul A. Zaveri

Chemistry Faculty Publications

Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO₃) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 decades, during which time a large body of research has emerged from laboratory, field, and modeling studies. NO₃-BVOC reactions influence air quality, climate and visibility through regional and global budgets for reactive nitrogen (particularly organic nitrates), ozone, and organic aerosol. Despite its long history of research and the significance of this topic in atmospheric chemistry, a number …

Synthesis Of Complex/Multifunctional Metal (Hydr)Oxide/Graphite Oxide/Aunps Or Agnps Adsorbents And Analysis Of Their Interactions With Chemical Warfare Agents, Dimitrios A. Giannakoudakis

Dissertations, Theses, and Capstone Projects

One of the most widely used chemical warfare agent (CWA) is mustard gas, which is a highly toxic blistering agent. In this study we investigated the interactions of mustard gas surrogates’ vapors on zinc and zirconium hydroxides and their composites with graphite oxide (GO) and/or Au or Ag nanoparticles. Even though a small quantity of reports about the detoxification of CWAs on metal oxides is reported in the literature, almost all of these studies are performed in the liquid phase. Both herein reported Zn(OH)₂ and Zr(OH)₄ showed a good adsorption performance, with the former being photoactive under visible …

Assessment Of Four Solvents For Extraction And Analysis Of The Chemical Composition Of Sansevieria Extrafoliar Nectar Drops By Gas Chromatography-Mass Spectrometry, Hope L. Juntunen, Patrick Videau, Donna Hazelwood, Michael Gaylor

Research & Publications

In the latter part of the 20th century, much effort was devoted to elucidating the chemical constituents of floral and extrafloral nectar secretions, with the primary aim of understanding their ecological roles, especially in regards to attracting pollinators. But, nearly all these studies focused on determining sugar and amino acid constituents. Only a few studies have reported more comprehensive assessments of the organic chemical constituents of plants, with none of those reporting such efforts for Sansevieria taxa (common houseplants known to purify air by bioaccumulating pollutants). To address this knowledge gap, we evaluated the efficacy of four organic solvents with …

Phthalate And Non-Phthalate Plasticizers In Indoor Dust From Childcare Facilities, Salons, And Homes Across The Usa, Bikram Subedi, Kenneth D. Sullivan, Birendra Dhungana

Faculty & Staff Research and Creative Activity

The quality of indoor environment has received considerable attention owing to the declining outdoor human activities and the associated public health issues. The prolonged exposure of children in childcare facilities or the occupational exposure of adults to indoor environmental triggers can be a culprit of the pathophysiology of several commonly observed idiopathic syndromes. In this study, concentrations of potentially toxic plasticizers (phthalates as well as non-phthalates) were investigated in 28 dust samples collected from three different indoor environments across the USA. The mean concentrations of non-phthalate plasticizers [acetyl tri-n-butyl citrate (ATBC), di-(2-ethylhexyl) adipate (DEHA), and diisobutyl adipate (DIBA)] were found …

Mass Loading And Removal Of Pharmaceuticals And Personal Care Products Including Psychoactives, Antihypertensives, And Antibiotics In Two Sewage Treatment Plants In Southern India, Bikram Subedi, Keshava Balakrishna, Derrick Ian Joshua, Kurunthachalam Kannan

Faculty & Staff Research and Creative Activity

Environmental contamination by pharmaceuticals and personal care products (PPCPs) is barely studied in India despite being one of the largest global producers and consumers of pharmaceuticals. In this study, 29 pharmaceuticals and six metabolites were determined in sewage treatment plants (STPs) in Udupi (STP_U: population served ~150,000) and Mangalore (STP_M: population served ~450,000); the measured mean concentrations ranged from 12 to 61,000 ng/L and 5.0 to 31,000 ng/L, respectively. Atorvastatin (the most prescribed antihypercholesterolemic in India), mefenamic acid, and paraxanthine were found for the first time in wastewater in India at the mean concentrations of 395 …

Digital Fabrication Of An Atmospheric Aerosol Impactor, Stefan J. Vincent, Shawn Daley, Matthew E. Wise

CUP Undergraduate Research

Atmospheric aerosol (AA) particles are defined as solid or liquid particles suspended in the air. AA particles smaller than 10 μm (1x10^-5 meters) in diameter are small enough to bypass the upper respiratory system which functions as a filter for harmful substances entering the lungs. AA particles can be collected using a device called an aerosol impactor. After collection, the particles can be analyzed offline for chemical composition using a variety of analytical techniques. The weight of a commercially manufactured AA particle impactor poses an issue if it is attached to a mobile AA particle sampling platform such as …

A Novel Method For Determination Of Ammonium Isotope Ratios With Electrospray Ionization Mass Spectrometry, Rebecca J. Chmiel

Honors Theses

Nitrogen (¹⁵N) isotope tracer studies are an invaluable tool for understanding the rate of N transformations in the environment. A mechanistic understanding of N cycling is critical to management of excess N availability in freshwater and marine ecosystems. Conventional methods for measuring ¹⁵N:¹⁴N of dissolved inorganic nitrogen species are time consuming and require large sample volumes. Here, we present a technique for measuring ¹⁵N:¹⁴N in ammonium (NH₄⁺) using electrospray ionization mass spectrometry (ESI-MS). NH₄⁺ present in small volumes of sample (3 ml) is complexed with phenol via …

Choline Chloride Eutectics: Low Temperature Applications, Kaila M. Kuehn, Camille M. Massmann, Natalie R. Sovell

The Journal of Undergraduate Research

Deep eutectic solvents (DESs) have a lower melting point than each of their individual components due to ion dipole interactions or hydrogen bonding. Traditionally, DES are used for processing metals through plating and have many synthesis applications. DES are able to be substituted for hazardous solvents that are traditionally used for metal plating and synthesis. This, along with many other advantageous properties, appear promising for the use of DESs as solvents or for use in electrochemical systems, particularly at low temperatures. Choline chloride:propylene glycol was a novel DES synthesized and analyzed for its properties, including melting point, viscosity, conductivity, heat …

Effects Of Nitrogen On Soil And Corn Yields, Doug W. Hughes

Natural Sciences Student Research Presentations

This poster for the Natural Sciences Poster Session at Parkland College describes the effects of nitrogen on soil and corn yields. Nitrogen has a major role in establishing and maintaining optimal photosynthesis in corn plants. A comparison shows that crops with more nitrogen applied produces healthier plants. The presentation also includes ways to reduce Nitrogen loss and the impact that Nitrogen rates have on the environment, corn yield, and cost to farmers.

Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik

Honors Theses and Capstones

The expansion of local agriculture in the New England region is putting increased pressure on farmers to expand their arable land base. While clear-cutting is a traditional method of converting forested land to agriculture, it is known for having adverse ecological impacts. To minimize these impacts, farmers can create a silvopasture which incorporates a portion of the original forest canopy into pastures or crop fields. This study evaluates the impact of land-use changes for agriculture on soil nitrogen (N) retention. In particular, this study investigates the differences in soil N turnover, gaseous loss, and aqueous loss among an established forest, …

Caffeine Used As A Tracer Of Wastewater Contamination In South Florida, Stephanie Spence

Honors Program Theses

In this study, a method was developed to analyze caffeine levels of water samples collected in Miami, Florida. The method was used to determine caffeine concentrations in reclaimed water samples and environmental water samples using on-line solid phase extraction (SPE) high pressure liquid chromatography (HPLC) high resolution mass spectrometry (HRMS). The rising use and disposal of pharmaceuticals and personal care products are becoming a concern as contaminants increasingly enter lakes, streams, and rivers without proper removal by traditional wastewater treatment processes. Caffeine may be used as a chemical tracer to indicate the presence of contamination in water samples and to …

Monitoring And Evaluation Of Terni (Central Italy) Air Quality Through Spatially Resolved Analyses, Lorenzo Massimi, Martina Ristorini, Marta Eusebio, Darla Florendo, Adeola Adeyemo, David Brugnoli, Silvia Canepari

Conference Papers

A study of spatial variability of PM10 elemental components was conducted in Terni city (Central Italy), situated in an intramountain depression characterized by the presence of several particulate matter emission sources. The meteorological conditions of the Terni basin limit the dispersion and enhance the accumulation of atmospheric pollutants. Thanks to the utilization of new smart samplers, used for the first time and working in parallel at 23 sampling sites, spatially resolved data were obtained. Localizations of the samplers were chosen in order to evaluate the impact of different local PM10 sources. Chemical composition of the samples was determined in combination …

Quantifying Carbonyl Sulfide And Other Sulfur-Containing Compounds Over The Santa Barbara Channel, Julia Black

Scripps Senior Theses

Carbonyl sulfide (OCS) is emitted to the atmosphere through the outgassing of ocean surface waters. OCS is also the primary source of sulfur-containing compounds in the stratosphere and contributes to the formation of the stratospheric sulfate layer, an essential controller of the radiative balance of the atmosphere. During the 2016 Student Airborne Research Program (SARP), 15 whole air samples were collected on the NASA DC-8 aircraft over the Santa Barbara Channel. Five additional surface samples were taken at various locations along the Santa Barbara Channel. The samples were analyzed using gas chromatography in the Rowland-Blake lab at UC Irvine, and …

Bioavailable Iron In Equatorial Pacific Ocean Aerosol Samples, Hsiang T Teng

All Master's Theses

Oceanic iron (Fe) fertilization experiments performed in remote regions have established that Fe additions draw carbon into the ocean, at least over the months-long time frame of the experiments. However, the mechanisms that control Fe speciation in atmospheric aerosol particles before and after deposition into the surface ocean remain largely unknown. This is in part due to the analytical challenge of quantifying Fe at environmentally significant sub-nano molar levels. The flow injection analysis method combined with the luminol chemiluminescence analytical system allows us to explore the near-real time determination of pico-molar levels of both Fe(II) and H₂O_{2 …}

A Miniaturized Spectrophotometric In Situ Ph Sensor For Seawater, Reuben C. Darlington

Graduate Student Theses, Dissertations, & Professional Papers

Since the Industrial Revolution, the world's oceans have absorbed increasing amounts of CO2 and the resultant changes to the marine carbonate chemical system have reduced the pH by > 0.1 units (~ 30%) in surface waters. This acidification of the oceans has many far reaching impacts on marine life and there is great need of quality instrumentation to assess and follow the changing carbonate system. This MIS project aims to develop a low cost pH sensor with high precision and accuracy for open sea measurements with special emphasis on reduced size and cost. Design effort is based on the commercially available …

Time-Resolved Phosphorescence Spectroscopy At Cryogenic Temperatures For The Environmental Analysis Of Polycyclic Aromatic Sulfur Heterocycles In Oil Contaminated Sites., Maha Al-Tameemi

Electronic Theses and Dissertations

The large volume of crude oil released into the Gulf of Mexico by the Deepwater Horizon (DWH) accident has raised considerable concerns over potential ecosystem impacts. The dispersion of harmful oil components into the ocean waters could pose long term risks to flora and fauna. Due to the complexity of oil contaminated sites, the unambiguous identification and quantitation of environmental pollutants often requires the sequence of high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). A classic example is the analysis of the sixteen polycyclic aromatic hydrocarbons included in the priority pollutants list of the U.S. Environmental Protection Agency (EPA-PAHs). …

Exploring The Effects Of Different Classroom Environments On The Learning Process. Synthesis Of Thiazole-Linked Porous Organic Polymers For Co2 Separation And Nitro-Aromatics Sensing., Davide D'Urbino

Theses and Dissertations

When attempting to study the learning process of undergraduate chemistry student, the classroom and any interaction that take place within it constitute the social context of interest. By studying how different approaches can foster different classroom environments, it is possible to approach course design from an informed and scientifically sound perspective. Thus, it becomes necessary to identify and quantify the factors that have a positive or negative effect on the classroom environment. Social comparison concerns, comfort levels and self-efficacy have been shown to be social factors that affect each other as well as the learning process and have therefore been …

Biomimetic Devices To Drive A Thermodynamically Uphill Reaction Using Light And To Degrade Industrial Waste Stream Components, Madison Joanne Sloan

Theses and Dissertations--Chemistry

Given the amount of industrial waste produced each year, as well as the accruing amount of greenhouse gases in our atmosphere produced by the burning of fossil fuels, it is imperative that humanity develop environmentally-sustainable sources of energy and methods of remediation. Nature achieves both of these by use of enzymes as catalysts, inspiring interest in designing biomimetic systems capable of harnessing clean energy and remediating industrial waste. This study examined the ability of enzymes in electrochemical and convective flow systems to achieve these tasks. The first portion studied the incorporation of enzymes into an electrochemical system to drive the …

Mechanisms Of Heterogeneous Oxidations At Model Aerosol Interfaces By Ozone And Hydroxyl Radicals, Elizabeth A. Pillar-Little

Theses and Dissertations--Chemistry

Atmospheric aerosols play an important role in climate by scattering and absorbing radiation and by serving as cloud condensation nuclei. An aerosol’s optical or nucleation properties are driven by its chemical composition. Chemical aging of aerosols by atmospheric oxidants, such as ozone, alters the physiochemical properties of aerosol to become more hygroscopic, light absorbing, and viscous during transport. However the mechanism of these transformations is poorly understood. While ozone is a protective and beneficial atmospheric gas in the stratosphere, it is a potent greenhouse gas in the troposphere that traps heat near the Earth’s surface. It also impacts human heath …

Heterogeneous Base Metal Catalyzed Oxidative Depolymerization Of Lignin And Lignin Model Compounds, John Adam Jennings

Theses and Dissertations--Chemistry

With the dwindling availability of petroleum, focus has shifted to renewable energy sources such as lignocellulosic biomass. Lignocellulosic biomass is composed of three main constituents, lignin, cellulose and hemicellulose. Due to the low value of cellulosic ethanol, utilization of the lignin component is necessary for the realization of an economically sustainable biorefinery model. Once depolymerized, lignin has the potential to replace petroleum-derived molecules used as bulk and specialty aromatic chemicals. Numerous lignin depolymerization strategies focus on cleavage of β-aryl ether linkages, usually at high temperatures and under reductive conditions.

Alternatively, selective benzylic oxidation strategies have recently been explored for …