Chemistry Commons^™

Evaluation Of Veterinary Pharmaceuticals And Iodine For Use As A Groundwater Tracer In Hydrologic Investigation Of Contamination Related To Dairy Cattle Operations, Larry Boot Pierce, Honglin Shi

Sinkhole Conference 2015

Standard groundwater tracers such as Rhodamine WT, Fluorescein, Eosin and Tinopal CBX effectively provide a snapshot of hydrological conditions over a brief period of time and in a tightly controlled setting. However, in complex environmental situations with multiple potential sources, groundwater hydrologists are often seeking groundwater tracers that have extended longevity in the natural environment and the ability to directly pinpoint source locations. After reviewing operations of the nearby dairy it was determined that emerging contaminants, specifically two bovine veterinary pharmaceuticals (antibiotics), cephapirin sodium (CEPNa) and cephapirin benzathine (CEPB), and a sanitation agent, elemental Iodine (I) may have potential as …

Using Nitrate, Chloride, Sodium, And Sulfate To Calculate Groundwater Age, Kimm Crawford, Terry Lee

Sinkhole Conference 2015

Regression analysis is used to identify monotonic trends to assign water age using ion data from two large well water databases from southeast Minnesota (SE MN). Nitrate (NO3-N), chloride (Cl), sodium (Na), and sulfate (SO4) ions in the commonly used aquifers in SE MN can be used as groundwater tracers since they are either entirely or partly anthropogenic in their sources, their loading occurs on a regional scale, and they are almost entirely conserved. Ion concentrations over time are used to establish six trend patterns. Two patterns are unchanging (background and stable above background), and four are changing (linear up, …

Source-Specific Molecular Signatures For Light-Absorbing Organic Aerosols, Amanda Susan Willoughby

Chemistry & Biochemistry Theses & Dissertations

Organic aerosols (OA) are universally regarded as an important component of the atmosphere based on quantitative significance as well as the far-reaching impact they have on global climate forcing and human health. Despite the acknowledged importance, OA amounts and impacts remain the largest uncertainties regarding radiative forcing estimates. Incomplete chemical characterization of aerosol organic matter (OM) and a lack of concrete source apportionment is a major source of this uncertainty. The primary focus of this study is to provide much needed molecular details regarding ambient OA from key emission sources, and establish links between molecular and optical properties.

Complete chemical …

Comparative Sorption Of Methylene Blue Onto Hydrophobic Clays, Alvaro D. Sponza, Natalia J. Fernandez, David Yang, Karla A. Ortiz, Abel E. Navarro

Publications and Research

Chemical modifications of clay to remove methylene blue (MB) from aqueous solutions at room temperature were compared. Natural bentonite (NC) was modified by cation exchange with hexadecyltrimethylammonium chloride (HC), bencyltriethylammonium chloride (BC), and tetramethylammonium chloride (TC) to reverse the surface polarity of the hydrophilic bentonite. The adsorption of MB was studied and fitted by the adsorption theories of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin. Equilibrium parameters were calculated, indicating that chemical modification did not improve the adsorption, due to the electrostatic adsorption mechanism. Specific surface area was determined, reporting the following trend: NC > TC > BC > HC. Isotherms show that TC is …

Nutrient Addition Effects On Tropical Dry Forests: A Mini-Review From Microbial To Ecosystem Scales, Jennifer S. Powers, Kristen K. Becklund, Maria G. Gei, Siddharth B. Iyengar, Rebecca Meyer, Christine S. O'Connell, Erik M. Schilling, Christina M. Smith, Bonnie G. Waring, Leland K. Werden

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Humans have more than doubled inputs of reactive nitrogen globally and greatly accelerated the biogeochemical cycles of phosphorus and metals. However, the impacts of increased element mobility on tropical ecosystems remain poorly quantified, particularly for the vast tropical dry forest biome. Tropical dry forests are characterized by marked seasonality, relatively little precipitation, and high heterogeneity in plant functional diversity and soil chemistry. For these reasons, increased nutrient deposition may affect tropical dry forests differently than wet tropical or temperate forests. Here, we review studies that investigated how nutrient availability affects ecosystem and community processes from the microsite to ecosystem scales …

Simulation Of Energetic Particle Precipitation Effects During The 2003-2004 Arctic Winter, C. E. Randall, V. L. Harvey, L. A. Holt, D. R. Marsh, D. Kinnison, B. Funke, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

Energetic particle precipitation (EPP) during the 2003-2004 Arctic winter led to the production and subsequent transport of reactive odd nitrogen (NO_x=NO+NO₂) from the mesosphere and lower thermosphere (MLT) into the stratosphere. This caused NO_x enhancements in the polar upper stratosphere in April 2004 that were unprecedented in the satellite record. Simulations of the 2003-2004 Arctic winter with the Whole Atmosphere Community Climate Model using Specified Dynamics (SD-WACCM) are compared to satellite measurements to assess our understanding of the observed NO_x enhancements. The comparisons show that SD-WACCM clearly displays the descent of NO_x produced …

Growth In Stratospheric Chlorine From Short-Lived Chemicals Not Controlled By The Montreal Protocol, R. Hossaoni, M. P. Chipperfield, A. Saiz-Lopez, J. J. Harrison, R. Von Glasow, R. Sommariva, E. Atlas, M. Navarro, S. A. Montzka, W. Feng, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

We have developed a chemical mechanism describing the tropospheric degradation of chlorine containing very short-lived substances (VSLS). The scheme was included in a global atmospheric model and used to quantify the stratospheric injection of chlorine from anthropogenic VSLS (Cl_y^VSLS) between 2005 and 2013. By constraining the model with surface measurements of chloroform (CHCl₃), dichloromethane (CH₂Cl₂), tetrachloroethene (C₂Cl₄), trichloroethene (C₂HCl₃), and 1,2-dichloroethane (CH₂ClCH₂Cl), we infer a 2013 Cl_y^VSLS mixing ratio of 123 parts per trillion (ppt). Stratospheric injection …

Nanodiamond Extraction At A Potential Impact Location, Joel Kathan

DePaul Discoveries

Meteoritic or cometary impacts create the temperature and pressure conditions necessary to form nanodiamonds (NDs). The presence of extracted NDs from rocks of the time and locations of extinctions, fires, or known environmental changes are commonly used to confirm that a theorized cosmic impact occurred to trigger those events. Samples were obtained from an archeological site described in the Old Testament of the Bible as having been destroyed by the God of the Old Testament.† To see if the historical description of Biblical events might have been triggered by a cometary impact or explosion, an attempt was made to …

On The Influence Of Ionic Strength On Radium And Strontium Sorption To Sandy Loam Soils, Brian A. Powell, Todd Miller, Daniel I. Kaplan

Journal of the South Carolina Academy of Science

Models which can estimate environmental transport of radioactive contaminants in natural and engineered systems are required to 1) deploy effective remediation strategies for contaminated sites, 2) design waste repositories for future waste streams, and 3) ensure protection of human and environmental health in all cases. These models require accurate transport parameters in order to correctly predict how these contaminants will move in the subsurface. This work aimed to determine more accurately the distribution coefficients for radium and strontium sorption to Savannah River Site (SRS) soils. Radium and strontium sorption to the soils was found to be highly dependent upon ionic …

Investigation Of The Potential For Algaenan To Produce Hydrocarbon Based Fuels From Algae By Hydrous Pyrolysis, Wassim Adel Obeid

Chemistry & Biochemistry Theses & Dissertations

The use of algae as a feedstock for hydrous pyrolysis has a high potential for producing biofuels. The non-food nature of algae in addition to the various advantages associated with the hydrous pyrolysis process makes this combination for the production of biofuels of high interest. However, current results from algae processing have alluded to some challenges: byproducts arising from the thermal transformation of carbohydrates and proteins, which become incorporated in the oil fraction, result in high oxygen and nitrogen contents of the oil. Accordingly, this produces an oil of low quality for refineries. This dissertation investigates use of a pretreatment …

The Effects Of Clay On Glycerol/Carboxylic Acid Polymerization: Implications Of Mineral Controls In Prebiotic Chemistry, Joseph T. Romero

Geology: Student Scholarship & Creative Works

Proto-enzymatic catalysis on early Earth is an important consideration in prebiotic chemistry research as it leads to the understanding of the emergence of the metabolic reaction networks. Contemporary enzymes are comprised of either organic or inorganic factors scaffolded by globular protein structure whereas we consider hyperbranched polyesters as a possible extant scaffold that is easier assembled than the peptide one. The goals of this project are to consider prebiotically plausible starting materials for such structure formation utilizing a subset of conditions for polymer synthesis involving the presence of mineral surfaces as well as temperature and hydration differential. As likely candidates …

Pyrolysis-Gc-Ms For The Rapid Environmental Forensic Screening Of Contaminated Brownfield Soil, Azucena Lara-Gonzalo, Michael A. Kruge, I Lores, B Gutiérrez, José Luis Gallego

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

An abandoned chemical plant in Asturias (Spain) was studied using a multi-faceted molecular fingerprinting approach, demonstrating that it is possible to: (1) carefully unravel tangled evidence resulting from multiple pollution sources, and (2) recognize major contaminants largely ignored by conventional analyses. This methodology employed a battery of GC-MS analyses of liquid chromatographic fractions of soil extracts, plus the pyrolysis products of the soil extract's asphaltene fraction and the whole soil itself. In this example, coal tar distillation and the subsequent production of naphthalene, phenols and polymer resins are responsible for most of the soil contamination. Styrene, naphthalene, indene, and their …

Analytical Pyrolysis Principles And Applications To Environmental Science, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Over the past half century, analytical pyrolysis has proven itself to be an effective means for the semiquantitative characterization of complex macromolecular organic substances. It has been demonstrated that instruments such as Py-FID, Py-MS, and in particular, Py-GC/MS can provide valuable geochemical insights when applied to a wide variety of problems in environmental science. The more widespread use of analytical pyrolysis methods in the evaluation of environmental pollution is recommended, because of their relatively low cost and information-rich results.

Pyrolysis is the heating of organic substances in an inert, oxygen-free atmosphere, thereby avoiding combustion. When performed on a large scale, …

Spectroscopic Characterization Of Oceanic Dissolved Organic Matter Isolated By Reverse Osmosis Coupled With Electrodialysis, John R. Helms, Jingdong Mao, Hongmei Chen, E. Michael Perdue, Nelson W. Green, Patrick G. Hatcher, Kenneth Mopper, Aron Stubbins

Chemistry & Biochemistry Faculty Publications

Oceanic dissolved organic matter (DOM) is one of the largest pools of reduced carbon on Earth, yet DOM remains poorly chemically characterized. Studies to determine the chemical nature of oceanic DOM have been impeded by the lack of efficient and non-fractioning methods to recover oceanic DOM. Here, a DOM fraction (~40 to 86% recovery) was isolated using reverse osmosis/electrodialysis (RO/ED) and analyzed by solid-state ¹³C nuclear magnetic resonance (NMR) spectroscopy. Samples were obtained from biogeochemically distinct environments: photobleached surface gyre, productive coastal upwelling zone, oxygen minimum, North Atlantic Deep Water, and North Pacific Deep Water. A ubiquitous ‘background’ refractory …

Use Of Esi-Fticr-Ms To Characterize Dissolved Organic Matter In Headwater Streams Draining Forest-Dominated And Pasture-Dominated Watersheds, Yuehan Lu, Xiaping Li, Rajaa Mesfioui, James E. Bauer, R. M. Chambers, Elizabeth A. Canuel, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) has proven to be a powerful technique revealing complexity and diversity of natural DOM molecules, but its application to DOM analysis in grazing-impacted agricultural systems remains scarce. In the present study, we presented a case study of using ESI-FTICR-MS in analyzing DOM from four headwater streams draining forest-or pasture-dominated watersheds in Virginia, USA. In all samples, most formulas were CHO compounds (71.8-87.9%), with other molecular series (CHOS, CHON, CHONS, and CHOP (N, S)) accounting for only minor fractions. All samples were dominated by molecules falling in the lignin-like region (H/C …

Long-Term Litter Decomposition Controlled By Manganese Redox Cycling, Marco Keiluweit, Peter Nico, Mark E. Harmon, Jingdong Mao, Jennifer Pett-Ridge, Markus Kleber

Chemistry & Biochemistry Faculty Publications

Litter decomposition is a keystone ecosystem process impacting nutrient cycling and productivity, soil properties, and the terrestrial carbon (C) balance, but the factors regulating decomposition rate are still poorly understood. Traditional models assume that the rate is controlled by litter quality, relying on parameters such as lignin content as predictors. However, a strong correlation has been observed between the manganese (Mn) content of litter and decomposition rates across a variety of forest ecosystems. Here, we show that long-term litter decomposition in forest ecosystems is tightly coupled to Mn redox cycling. Over 7 years of litter decomposition, microbial transformation of litter …

Characterization Of Terrestrial Dissolved Organic Matter Fractionated By Ph And Polarity And Their Biological Effects On Plant Growth, Rachel L. Sleighter, Paolo Caricasole, Kristen M. Richards, Terry Hanson, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Background: Humic substances are ubiquitous in the environment, complex mixtures, and known to be beneficial to plant growth. To better understand and identify components responsible for plant growth stimulation, a terrestrial aquatic DOM sample was fractionated according to pH and polarity, obtaining acid-soluble and acid-insoluble portions, as well as acid-soluble hydrophobic and hydrophilic fractions using C18. The various fractions were characterized then evaluated for their biological effects on plant growth using bioassays with corn at two carbon rates.

Results: Approximately 43% and 57% of the carbon, and 31% and 69% of the iron, was found in the acid-insoluble and acid-soluble …

Optical Characterization And Distribution Of Chromophoric Dissolved Organic Matter (Cdom) In Soil Porewater From A Salt Marsh Ecosystem, Catherine D. Clark, Paige Aiona, Jason K. Keller, Warren J. De Bruyn

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

To characterize chromophoric dissolved organic matter (CDOM) in marsh porewaters and its contribution as a carbon source, optical properties (absorbance, fluorescence indices, 3-dimensional excitation-emission matrices [EEMs]) of soil porewater and surface water were measured in a southern Californian salt marsh. Absorption coefficients and fluorescence intensities were higher in porewater than in overlying surface waters, consistent with higher CDOM concentration at depth. Humic-type peaks A and C were observed in EEMs in all samples, and peak M was observed in surface waters and shallow porewater to -5 cm depth. Fluorescence:absorbance (flu:abs) ratios and spectral slopes (S) decreased across the surface interface, …

Toward Understanding The Thermodynamics And Mechanisms Of Actinide Sorption Reactions, Shanna Estes

All Dissertations

The environmental fate of actinides is greatly influenced by interfacial reactions, including sorption onto solid surfaces. Because changes in the primary hydration sphere of the actinide are expected to greatly influence the thermodynamics (i.e., reaction enthalpy and entropy) of these reactions, examining actinide sorption thermodynamics may provide insight into actinide sorption mechanisms. Additionally, examining actinide sorption thermodynamics may enhance the ability to model or predict these reactions in environmental or engineered systems where variable or elevated temperatures are expected. However, few researchers have studied actinide sorption thermodynamics. Therefore, this research examined the thermodynamics of Eu(III) (a trivalent actinide analog), Th(IV), …

Peptide Arrays For Detecting Naphthenic Acids In Oil Sands Process Affected Water, Kamaljit Kaur, Subir Bhattacharjee, Rajesh G. Pillai, Sahar Ahmed, Sarfuddin Azmi

Pharmacy Faculty Articles and Research

Naphthenic acids (NAs) are water-soluble components of petroleum. The characterization and quantification of NAs by analytical methods have proved quite challenging, whilst the toxic effects of these water-soluble compounds on a variety of organisms adversely affecting reproduction and steroid production is becoming apparent. In this study, we report a fluorescence-based competitive binding method for rapid sensing of the presence of NAs using cellulosic peptide array strips as sensors. The peptide array was designed from sequences derived from the estrogen receptor (ER). Several of these peptides were able to detect the presence of NAs at low micromolar (∼5 mg L^{−1 …}

Iron Sources And Dissolved-Particulate Interactions In The Seawater Of The Western Equatorial Pacific, Iron Isotope Perspectives, M. Labatut, F. Lacan, C. Pradoux, J. Chmeleff, A. Radic, J. W. Murray, F. Poitrasson, Anne M. Johansen, F. Thil

All Faculty Scholarship for the College of the Sciences

This work presents iron isotope data in the western equatorial Pacific. Marine aerosols and top core margin sediments display a slightly heavy Fe isotopic composition (δ⁵⁶Fe) of 0.33 ± 0.11‰ (2SD) and 0.14 ± 0.07‰, respectively. Samples reflecting the influence of Papua New Guinea runoff (Sepik River and Rabaul volcano water) are characterized by crustal values. In seawater, Fe is mainly supplied in the particulate form and is found with a δ⁵⁶Fe between −0.49 and 0.34 ± 0.07‰. The particulate Fe seems to be brought mainly by runoff and transported across continental shelves and slopes. …

Carbon And Nitrogen Dynamics From Slow Pools Of Soil Organic Matter In A Temperate Forest: Pyrogenic Organic Matter And And Root Litter, Fernanda Dos Santos

Dissertations, Theses, and Capstone Projects

Soil organic matter (SOM) is the dominant reservoir of organic carbon (OC) in terrestrial ecosystems, storing approximately three times the size of the C pool in the atmosphere. In temperate forests, a major fraction of the SOM consists of slowly decaying soil organic C (SOC) pools. While slowly cycling C pools constitute a large reservoir of stable C in soils, the dominant environmental factors controlling this C pool remain unresolved. This research investigates two significant, but poorly characterized slowly decaying C pools: fine root litter (< 2mm) and thermally altered plant biomass (pyrogenic organic matter, PyOM). Specifically, I used compound-specific stable isotope analysis (¹³C and ¹⁵N) as my main methodological approach to examine the (1) …

Ice Caves On Extraterrestrial Bodies: What Are The Prospects For Speleogenesis And Detection?, Penelope J. Boston

The International Workshop on Ice Caves

Potential mechanisms for creating cavities in icy extraterrestrial bodies have been tentatively explored by several authors. On one hand we have examples of mechanisms that create caves in water ice here on Earth. In addition, there may be unique mechanisms on other Solar System objects that do not occur on Earth but might produce cavities, e.g. sublimation of comets upon perihelion passage. The methods of detecting such cavities depend upon the nature of the icy body in question, the potential for orbital or landed missions to visit those bodies in the future, and remote or landed methods for detecting the …

Detecting Non-Seismic Precursor Earthquake Signals Using Tree Antennas, Jaqueline O. Lopez

STAR Program Research Presentations

Forecasting earthquakes has yet to be achieved. However, there are numerous non-seismic precursor signals, which become detectable weeks to days before major events – for instance changes in Earth’s electrical surface potential. These changes are due to the arrival of positive electronic charge carriers, known as positive holes, stress-activated deep in the Earth’s crust, in the hypocenter of the future earthquake. Trees can be used as antennas for detecting the surface potential changes due to these mobile charges. This configuration allows for the detection of diurnal variations of the ground potential. Although we only had 105 days worth of data, …

Carbon Sequestration In Tidal Salt Marshes And Mangrove Ecosystems, Carlos Eduardo Quintana-Alcantara

Master's Projects and Capstones

Wetlands are dynamic systems that provide support to vital environmental functions and services. Wetlands take part in the global carbon cycle by holding organic carbon in biomass, soils and sediments. In recent years, the wetland carbon sequestration capacity has been researched worldwide due to the increase of the concentrations of greenhouse gasses implicated in global warming and climate change. Although coastal wetlands release the greenhouse gasses carbon dioxide, methane and nitrous oxide, these ecosystems maintain high performance in offsetting significant amounts of atmospheric carbon. This paper investigated the carbon sequestration capacity of coastal wetland ecosystems summarizing the environmental conditions and …

Comparative Analysis Of Two Successive Vintages Of Cabernet Sauvignon Must And Pre-Barrel Wine From Two Distinct Soil Types, Jon Garret Page

Master's Theses

The objective of this study was to determine if there were significant statistical differences in the response variables of Cabernet Sauvignon must and pre-barreled wine analyzed from two vintages from two distinct soil types.

Research was conducted at California Polytechnic University, San Luis Obispo to examine the quantitative chemical analysis of 22 different response variables of Cabernet Sauvignon grapes. The same 22 variables were analyzed in must and pre-barreled wine samples harvested from both Calodo Clay Loam soil and Zaca Clay soil. The analyses were done at both California Polytechnic University, San Luis Obispo and Vinquiry Inc. Labs. The results …

A Review Of Air–Ice Chemical And Physical Interactions (Aici): Liquids, Quasi-Liquids, And Solids In Snow, T. Bartels-Rausch, H-W Jacobi, T. F. Kahan, J. L. Thomas, E. S. Thomson, J. P. D. Abbatt, M. Ammann, J. R. Blackford, H. Bluhm, Chris Boxe, F. Domine, M. M. Frey, I. Gladich, M. I. Guzmán, D. Heger, Th. Huthwelker, P. Klán, W. F. Kuhs, M. H. Kuo, S. Maus, S. G. Moussa, V. F. Mcneill, J. T. Newberg, J. B. C. Pettersson, M. Roeselová, J. R. Sodeau

Publications and Research

Snow in the environment acts as a host to rich chemistry and provides a matrix for physical exchange of contaminants within the ecosystem. The goal of this review is to summarise the current state of knowledge of physical processes and chemical reactivity in surface snow with relevance to polar regions. It focuses on a description of impurities in distinct compartments present in surface snow, such as snow crystals, grain boundaries, crystal surfaces, and liquid parts. It emphasises the microscopic description of the ice surface and its link with the environment. Distinct differences between the disordered air–ice interface, often termed quasi-liquid …

A Review Of The Hyporheic Zone, Stream Restoration, And Means To Enhance Denitrification, Leanne Merill, David J. Tonjes

Technology & Society Faculty Publications

The hyporheic zone is the subsurface area below and adjacent to a stream where groundwater mixes with stream water, through vertical, lateral, and longitudinal flows. The hyporheic zone connects the stream to uplands and other terrestrial environments. It is a zone of distinct faunal communities, high biological diversity and ecological complexity, and is the site of chemical processing and transformations of ground- and stream waters. The hyporheic zone is important to the overall ecosystem ecology of the stream, and it can influence stream water chemistry. Flows, reactions, and biota in the hyporheic zone are heterogeneous and patchy, making it difficult …

Monitoring The Influence Of Acid Deposition On Soil And Implications To Forest Health In The Daniel Boone National Forest, Tyler M. Sanderson

Theses and Dissertations--Forestry and Natural Resources

Combustion of fossil fuels has contributed to many environmental problems including acid deposition. The Clean Air Act (CAA) was created to reduce ecological problems by cutting emissions of sulfur and nitrogen. Reduced emissions and rainfall concentrations of acidic ions have been observed since the enactment of the CAA, but soils continue to receive some acid inputs. Soils sensitive to acid deposition have been found to have low pH, a loss of base cations and a shift in the mineral phase controlling the activity of Al³⁺ and/or SO₄^2-. If inputs continue, soil may be depleted of base …

Zn(Ii) And Cu(Ii) Adsorption And Retention Onto Iron Oxyhydroxide Nanoparticles: Effects Of Particle Aggregation And Salinity, Rebecca B. Chesne, Christopher S. Kim

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Iron oxyhydroxides are commonly found in natural aqueous systems as nanoscale particles, where they can act as effective sorbents for dissolved metals due to their natural surface reactivity, small size and high surface area. These properties make nanoscale iron oxyhydroxides a relevant option for the remediation of water supplies contaminated with dissolved metals. However, natural geochemical processes, such as changes in ionic strength, pH, and temperature, can cause these particles to aggregate, thus affecting their sorption capabilities and remediation potential. Other environmental parameters such as increasing salinity may also impact metal retention, e. g. when particles are transported …