Environmental Chemistry Commons^™

The Investigation Of Lactoferrin Nitration: Quantification, Function, And Inhibition, Amani Yahya Alhalwani

Electronic Theses and Dissertations

Lactoferrin (LF) is an iron-binding glycoprotein of molecular mass ca. 80 kDa that is predominantly found in mammalian body fluids. Lactoferrin is a multifunctional protein that has a wide range of properties such as antibacterial, antiviral, anti-inflammatory, and anti-allergic functions. Tyrosine residues in the protein play a part in many lactoferrin functions. Protein tyrosine nitration modification represents an oxidative and nitrosative stress process which can be caused by the exposure of proteins to oxidants from air pollution or disease. Understanding the way nitrated lactoferrin interacts with the biochemical environment of the body is thus important to the broader goal of …

Environmental Forensics Study Of Crude Oil And Petroleum Product Spills In Coastal And Oilfield Settings: Combined Insights From Conventional Gc-Ms, Thermodesorption-Gc-Ms And Pyrolysis-Gc-Ms, Michael A. Kruge, José Luis Gallego, Azucena Lara-Gonzalo, Noemi Esquinas

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

A representative set of five oil spill samples from four different regions displayed different product characteristics and different levels of weathering. Three of them were taken along shorelines affected by marine oil spill events, viz., Aboño and Prestige (Spain) and Deepwater Horizon (USA) and the other two were taken at inland oil spill sites (Angola and Kuwait). A multi-faceted environmental forensics approach revealed key molecular features. In addition to the conventional GC/MS analysis of saturated and aromatic fractions, the polar fractions also were analyzed, revealing a complex series of linear alkanones in those oil samples particularly enriched in aliphatics. Thermodesorption-GC-MS …

A Modeling Toolbox For Permafrost Landscapes, Irina Overeem, Elchin Jafarov, Kang Wang, Kevin Schaefer, Scott Stewart, Gary Clow, Mark Piper, Yasin Elshorbany

USF St. Petersburg Campus Faculty Publications

No abstract provided.

Presence And Potential Sources Of Pharmaceutical And Personal Care Product Chemicals In Messalonskee Lake, Alyssa T. Kullberg

Honors Theses

Pharmaceuticals and personal care product chemicals (PPCPs) represent a large group of contaminants that are mostly not regulated in surface or drinking water and whose presence and environmental and health impacts are poorly understood. We investigated the presence and potential sources of 18 PPCPs in Messalonskee Lake. We collected samples four times over the summer of 2017 at 13 sites around the lake. Samples were tested for PPCPs using liquid chromatography-tandem mass spectrometry. We detected five out of the 18 PPCPs we tested for at the ng/L level: caffeine, 1,7-dimethylxanthine, acetaminophen, sulfachloropyridazine, and amphetamine. PPCPs showed a significant positive correlation …

Stable Bromine Isotope Signature Of Bromoform From Enzymatic And Abiotic Formation Pathways And Its Application In Identifying Sources Of Environmental Bromoform In The Damariscotta River, Chengyang Wang

Honors Theses

Bromoform is a major source of atmospheric bromine. Most bromoform is produced by marine organisms including macroalgae and phytoplankton, using the enzyme bromoperoxidase (BPO). Bromoform can also be a byproduct of industrial processes such as water disinfection. Identifying sources of environmental bromoform is still a challenge. A novel technique of using quadrupole mass spectrometry coupled to a gas chromatography (GCqMS) was developed and optimized for Br isotope analyses. The study shows that GCqMS in single ion monitoring (SIM) mode can measure 81Br with precision of around ±0.7‰ (60pmol bromoform injected). This study aims to investigate stable Br isotopes of bromoform …

Perspectives On Chemical Oceanography In The 21st Century: Participants Of The Come Aboard Meeting Examine Aspects Of The Field In The Context Of 40 Years Of Disco, Andrea J. Fassbender, Hilary I. Palevsky, Todd R. Martz, Anitra E. Ingalls, Martha Gledhill, Sarah E. Fawcett, Jay A. Brandes, Lihini I. Aluwihare, The Participants Of Come Aboard, Disco Xxv

OES Faculty Publications

The questions that chemical oceanographers prioritize over the coming decades, and the methods we use to address these questions, will define our field's contribution to 21st century science. In recognition of this, the U.S. National Science Foundation and National Oceanic and Atmospheric Administration galvanized a community effort (the Chemical Oceanography MEeting: A BOttom-up Approach to Research Directions, or COME ABOARD) to synthesize bottom-up perspectives on selected areas of research in Chemical Oceanography. Representing only a small subset of the community, COME ABOARD participants did not attempt to identify targeted research directions for the field. Instead, we focused on how best …

Interpreting Mosaics Of Ocean Biogeochemistry, Andrea Fassbender, A. Bourbonnais, Sophie Clayton, P. Gaube, M. Ormand, P.J.S. Franks, M. A. Altabet, D.J. Mcgillicuddy Jr.

OES Faculty Publications

Advances in technology and modeling capabilities are driving a surge in progress in our understanding of how ocean ecosystems mix and mingle on medium to small scales.

Water Oxidation: Replicating The Power Of Photosynthesis, Flora Denton

Natural Sciences Student Research Presentations

This poster for the Natural Sciences Poster Session at Parkland College details the chemical process of oxygenic photosynthesis, summarizes efforts to study the photosystem II process as well as potential applications.

Determination Of The Oxidative Capacity Of Soot Toward Gsh And Characterization Of Soot Physicochemical Properties, Kaylee Troth

All Master's Theses

Fine atmospheric particulate matter (PM_2.5) emitted during the combustion of fossil and biomass fuels is known to adversely affect human health. While the underlying mechanisms are thought to be driven by the generation of reactive oxygen species (ROS), specific particle characteristics responsible for this detrimental effect are not well understood. In this research, the quantitative determination of the biologically relevant antioxidant, glutathione (GSH), was optimized for use as an indicator of oxidative stress to shed light on relevant particle characteristics. This was accomplished via fluorescent spectroscopy for GSH determination by way of reaction with o-phthalaldehyde (OPA), a …

A Model To Predict Concentrations And Uncertainty For Mercury Species In Lakes, Ashley Hendricks

Dissertations, Master's Theses and Master's Reports

To increase understanding of mercury cycling, a seasonal mass balance model was developed to predict mercury concentrations in lakes and fish. Results indicate that seasonality in mercury cycling is significant and is important for a northern latitude lake. Models, when validated, have the potential to be used as an alternative to measurements; models are relatively inexpensive and are not as time intensive. Previously published mercury models have neglected to perform a thorough validation. Model validation allows for regulators to be able to make more informed, confident decisions when using models in water quality management. It is critical to quantify uncertainty; …

Surface Oxygenation Of Biochar Through Ozonization For Dramatically Enhancing Cation Exchange Capacity, Matthew D. Huff, Sarah Marshall, Haitham A. Saeed, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

Background

Biochar cation exchange capacity (CEC) is a key property that is central to biochar environmental applications including the retention of soil nutrients in soil amendment and removal of certain pollutants in water-filtration applications.

Results

This study reports an innovative biochar-ozonization process that dramatically increases the CEC value of biochars by a factor of 2. The ozonized biochars also show great improvement on adsorption of methylene blue by as much as a factor of about 5. In this study, biochar samples treated with and without ozone were analyzed by means of pH and CEC assays, water field capacity measurement, elemental …

Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia, Nikolai F. Zobov, Phillip A. Coles, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Robert J. Hargreaves, Peter F. Bernath, Jonathan Tennyson, Sergei N. Yurchenko, Oleg L. Polyansky

Chemistry & Biochemistry Faculty Publications

Room temperature NH₃ absorption spectra recorded at the Kitt Peak National Solar Observatory in 1980 are analyzed. The spectra cover two regions in the visible: 15,200 - 15,700 cm^-1 and 17,950 - 18,250 cm^-1. These high overtone rotation-vibration spectra are analyzed using both combination differences and variational line lists. Two variational line lists were computed using the TROVE nuclear motion program: one is based on an ab initio potential energy surface (PES) while the other used a semi-empirical PES. Ab initio dipole moment surfaces are used in both cases. 95 energy levels with J = 1 …

Fabrication Of Mnox/Mwcnts-Gc Nanocatalyst For Oxygen Evolution Reaction, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Amr M. Arafa Eng.

Chemical Engineering

Manganese oxide (MnOx) and multiwalled carbon nanotubes (MWCNTs) are intended to modify the GC electrode for oxygen evolution reaction (OER). Optimization of MnOx loading is carried out and the deposition of 55 cycles was sufficient to obtain the highest activity toward OER. The stability of the catalyst is enhanced by the addition of MWCNTs. As a result, an amount of 22 kWh/Kg of O2 of energy is saved. Several techniques including cyclic voltammetry, linear sweep voltammetry, chronoamperometry, chronopotentiometry, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy will be combined to track the catalyst activity and to determine its morphology …

Assembling Of Niox/Mwcnts-Gc Anodic Nanocatalyst For Water Electrolysis Applications, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Saher D. Khamis Eng

Chemical Engineering

Glassy carbon (GC) electrode is intended to be modified with nickel oxide (NiOx) and multiwalled carbon nanotubes (MWCNTs) in the anodic reaction of water electrolysis. NiOx deposition time is optimized and a 5 min was enough to attain the maximum activity. A further modification of the catalyst with MWCNTs could greatly enhance its stability during continuous electrolysis. As an outcome, an energy amount of 21.7 kWh/KgO2 is minimized. Several electrochemical and materials characterization setups will be utilized to test the catalyst activity and to know its geometry and structure.

Fabrication Of Cuox-Pd Nanocatalyst Supported On A Glassy Carbon Electrode For Enhanced Formic Acid Electro-Oxidation, Islam M. Al-Akraa Dr., Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

Formic acid (FA) electro-oxidation (FAO) was investigated at a binary catalyst composed of palladium nanoparticles (PdNPs) and copper oxide nanowires (CuOxNWs) and assembled onto a glassy carbon (GC) electrode. /e deposition sequence of PdNPs and CuOxNWs was properly adjusted in such a way that could improve the electrocatalytic activity and stability of the electrode toward FAO. Several techniques including cyclic voltammetry, chronoamperometry, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction were all combined to report the catalyst’s activity and to evaluate its morphology, composition, and structure. /e highest catalytic activity and stability were obtained at the CuOx/Pd/GC …

The Study Of The Degradation Of Hexabromocyclododecane In A Heterogeneous System Containing Fe(Ii) Adsorbed To The Iron Oxide Hematite., Kristian K. Roopnarine

Dissertations and Theses

The reaction of hexabromocyclododecane (HBCDD), a widely used brominated flame retardant, was studied in a heterogenous mixture containing reactive Fe(II) adsorbed to the iron oxide hematite. The adsorbed Fe(II)/iron oxide system has shown to be a potent reductant in the transformation of organic contaminants with relatively water soluble organic contaminants. There currently aren’t many studies involving hydrophobic organic contaminants, such as HBCDD, in this reducing Fe(II)/iron oxide system. The results indicate that across the pHs 6.86, 6.95, 7.15 and 7.35 γ and β-HBCDD are degraded within a couple days. The pseudo-first order rate constants at pH 6.95 are 0.049 hr …

The Development Of A Simplified Alkalinity Titration Analyzer, Reba Van Beusekom

Graduate Student Theses, Dissertations, & Professional Papers

Alkalinity is the acid neutralizing capacity for water, meaning alkalinity measures how sensitive an aquatic system is to acidic inputs. Currently, there are various measuring systems for alkalinity available including chemical test kits, potentiometric techniques, and colorimetric methods. Commercially available products lack the ease of use combined with precision and accuracy desired for on-line process and environmental monitoring. The goal of this project is to develop a simplified alkalinity titration analyzer, called the easyTMT, to measure alkalinity with precision and accuracy comparable to the best conventional methods. The system, under development, uses the Tracer Monitored Titration (TMT) technique. TMT …

Aqueous Photochemistry Of 2-Oxocarboxylic Acids, Alexis Eugene

Theses and Dissertations--Chemistry

Atmospheric aerosols affect climate change by altering the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosol (SOA) from gas phase precursors is relatively well understood, it does not account for the abundance of SOA observed during field measurements. Recently it has become apparent that in-aerosol aqueous chemical reactions likely provide some of the missing sources of SOA production, and many studies of aqueous phase processes are underway.

This work explores the fates of the simplest 2-oxocarboxylic acids, glyoxylic acid (GA) and pyruvic acid (PA), …

Evaluation Of Autonomously Measured Alkalinity, Ph, And Pco2 Variability On A Coral Reef, Brittany Peterson

Graduate Student Theses, Dissertations, & Professional Papers

Currently, our understanding of alkalinity (A_T) variability in highly dynamic environments such as coral reefs is limited by the dearth of A_T measurements. In order to better characterize these environments, high temporal resolution A_T data are needed. This work employed the newly developed Submersible Autonomous Moored Instrument for Alkalinity (SAMI-alk), a fully autonomous in situ A_T analyzer, to study seawater A_T variability. The main goals of this research were to evaluate the utility of combining the SAMI-alk data with currently available in situ measurements of pH and partial pressure of carbon dioxide (p …

Development Of Photocatalysts Supported On Graphitic Carbon Nitride For The Degradation Of Organic Water Pollutants, Atanu Giri

Theses and Dissertations

Graphitic carbon nitride (g-C₃N₄) heterojunction composites with the semiconducting metal oxides, CeO₂, ZnO and TiO₂ are prepared in situ by co-calcination of the precursor materials or by a solvothermal method. The structural, morphological and the optical properties of the prepared materials are studied using various microscopy and spectroscopy techniques. The synthesized composite materials, CeO₂/g-C₃N₄, ZnO/g-C₃N₄ and TiO₂/g-C₃N₄ are more efficient in the photocatalytic degradation of the water pollutants indigo carmine (IC) and atrazine than the pure metal oxide, g-C …