Investigating Potential Pollutant Sources Causing Lack Of Biodiversity In Lytle Creek And Indian Run, 2017 Wright State University - Main Campus
Investigating Potential Pollutant Sources Causing Lack Of Biodiversity In Lytle Creek And Indian Run, Audrey E. Mcgowin, Amira Alsenbel, Harry Mcvey, Lori Williams, Taylor Stuckert
Chemistry Faculty Publications
This report describes the results of research performed with funds from the Sture Fredrik Anliot Grant Fund granted in March 2016 and the Wright State University College of Science and Mathematics. The title of the grant was “Lytle Creek and Indian Run Sediment and Water Pollution Assessment” and its primary aim was to identify and measure pollutants that could be causing a lack of biodiversity in Lytle Creek in Wilmington, OH. The project formed the basis of Amira Alsenbel’s Masters in Chemistry thesis research.
Spatial And Temporal Determinants Of A-Weighted And Frequency Specific Sound Levels—An Elastic Net Approach, 2017 Harvard T.H. Chan School of Public Health
Spatial And Temporal Determinants Of A-Weighted And Frequency Specific Sound Levels—An Elastic Net Approach, Erica D. Walker, Jaime E. Hart, Petros Koutrakis, Jennifer M. Cavallari, Trang Vopham, Marcos Luna, Francine Laden
Geography Faculty Publications
Background: Urban sound levels are a ubiquitous environmental stressor and have been shown to be associated with a wide variety of health outcomes. While much is known about the predictors of A-weighted sound pressure levels in the urban environment, far less is known about other frequencies.
Objective: To develop a series of spatial-temporal sound models to predict A-weighted sound pressure levels, low, mid, and high frequency sound for Boston, Massachusetts.
Methods: Short-term sound levels were gathered at n = 400 sites from February 2015 – February 2016. Spatial and meteorological attributes at or near the sound monitoring site were obtained using publicly ...
Numerical Simulations Of The Biogeochemical Impact Of Atmospheric Nitrogen Deposition On Surface Waters Of The Western North Atlantic, 2017 Virginia Institute of Marine Science
Numerical Simulations Of The Biogeochemical Impact Of Atmospheric Nitrogen Deposition On Surface Waters Of The Western North Atlantic, Pierre St-Laurent, Marjorie A.M. Friedrichs
The impacts of atmospheric nitrogen deposition on the chlorophyll and nitrogen dynamics of surface waters in the western North Atlantic (25-45N, 65-80W) were examined with a biogeochemical ocean model forced with a regional atmospheric chemistry model. The model simulations cover the period 2004 to 2008 and are fully described in the following reference: St-Laurent, P., et al., Impacts of atmospheric nitrogen deposition on surface waters of the western North Atlantic mitigated by multiple feedbacks, J. Geophys. Res. Oceans, vol.122, doi:10.1002/2017jc013072.
Mobility Characteristics Of Azithromycin In Soil, 2017 Purdue University
Mobility Characteristics Of Azithromycin In Soil, Ryan Minter, Jihyun Kim, Linda Lee
The Summer Undergraduate Research Fellowship (SURF) Symposium
The presence of pharmaceutical and personal care products (PPCPs) in the environment has become a widespread problem in recent decades. Azithromycin, a macrolide antibiotic commonly prescribed for infections in humans, has been detected in waste treatment plant discharge and surface waters across the world. Data on the mobility characteristics of azithromycin in soil is scarce, and further studies must be performed to explore the potential for azithromycin leaching to groundwater or becoming available for plant uptake. In this study, azithromycin sorption isotherms were measured on eight soils varying in pH, organic carbon content, and clay content. Soil was equilibrated with ...
Geochemical Fractionation, Speciation, And Bioavailability Of Heavy Metals In Stream Sediments In Aurora, Mo, 2017 Missouri State University
Geochemical Fractionation, Speciation, And Bioavailability Of Heavy Metals In Stream Sediments In Aurora, Mo, Miles Pearson
MSU Graduate Theses
Stream sediments from Chat Creek in Aurora, MO, part of the former Tristate Mining District, were digested via a sequential extraction procedure modeled after the Tessier method. Prior sampling had shown elevated levels of zinc, lead, and cadmium in sediments located near former chat piles. Metals in sediments were divided into four geochemical fractions: 1) easily exchangeable, 2) carbonate-bound, 3) iron-manganese oxides-bound, and 4) organic matter-bound. The distribution of the metals within these fractions can help predict the bioavailability and speciation of said metals. The majority of metals were contained in the third and to a lesser extent the fourth ...
Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, 2017 Plymouth Marine Laboratory
Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. De Bruyn, Adrian H. Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, Eric S. Saltzman
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Simultaneous air–sea fluxes and concentration differences of dimethylsulfide (DMS) and carbon dioxide (CO2/ were measured during a summertime North Atlantic cruise in 2011. This data set reveals significant differences between the gas transfer velocities of these two gases (1kw/ over a range of wind speeds up to 21ms1. These differences occur at and above the approximate wind speed threshold when waves begin breaking. Whitecap fraction (a proxy for bubbles) was also measured and has a positive relationship with 1kw, consistent with enhanced bubble-mediated transfer of the less soluble CO2 relative to that of the more soluble DMS. However ...
Macroporous Carbon Supported Zerovalent Iron For Remediation Of Trichloroethylene, 2017 Iowa State University
Macroporous Carbon Supported Zerovalent Iron For Remediation Of Trichloroethylene, Michael Lawrinenko, Zhuangji Wang, Robert Horton, Deyny Mendivelso-Perez, Emily A. Smith, Terry E. Webster, David A. Laird, Johannes Van Leeuwen
Groundwater contamination with chlorinated hydrocarbons has become a widespread problem that threatens water quality and human health. Permeable reactive barriers (PRBs), which employ zerovalent iron, are effective for remediation; however, a need exists to reduce the economic and environmental costs associated with constructing PRBs. We present a method to produce zerovalent iron supported on macroporous carbon using only lignin and magnetite. Biochar-ZVI (BC-ZVI) produced by this method exhibits a broad pore size distribution with micrometer sized ZVI phases dispersed throughout a carbon matrix. X-ray diffraction revealed that pyrolysis at 900 °C of a 50/50 lignin–magnetite mixture resulted in ...
Comprehensive Silica Removal With Ferric Compounds For Industrial Wastewater Reuse, 2017 University of New Mexico
Comprehensive Silica Removal With Ferric Compounds For Industrial Wastewater Reuse, Ehren D. Baca
Civil Engineering ETDs
Cooling towers, integrated circuit (IC) manufacture and reverse osmosis (RO) generate copious amounts of wastewater high in colloidal and reactive silica inhibiting on-site or synergistic reuse. Silica present in cooling water can reach solubility limits via evaporation and form impervious scale on heat transfer surfaces that decreases efficiency. When water is treated by RO operating at high rejection, silica forms difficult-to-remove scale on the membrane feed side in the form of glassy patches and communities of aggregate particles, inhibiting aspirations for zero liquid discharge. Current methods for silica scale mitigation include abundant dosing with chemical antiscalents or complex operating schemes ...
Evaluation Of A Filtration Sorbent For Remediation Of Arsenic In Groundwater, 2017 California State University - San Bernardino
Evaluation Of A Filtration Sorbent For Remediation Of Arsenic In Groundwater, Clement Do
Electronic Theses, Projects, and Dissertations
A commercially available product, PURA PhosLock, was identified and evaluated for use as a sorbent to remove dissolved arsenic (As) from drinking water. Although marketed as a product to remove phosphate in aquaria, it is composed of iron oxide hydroxide (i.e., FeO(OH)), which is also known to adsorb dissolved As species from water. Arsenic was measured using standard methods and Graphite Furnace Atomic Absorption Spectroscopy. A first rough filtration test was performed to see if the PhosLock adsorbed As well. About 50 g of PhosLock was used to filter 10 L of tap water containing 100 ppb As ...
Pine Needle Pyrolysis: Bio-Waste Into Biofuel, 2017 Dominican University of California
Pine Needle Pyrolysis: Bio-Waste Into Biofuel, Alexandra Fuentes
Honors Theses and Capstone Projects
This project explores the alternate uses of biomass. In particular it focuses on pine needles as a source for biofuels. Pine needles are of interest because in certain Mountain communities they are collected and removed from residential properties. By removing the pine needles, communities create a “defensible space” to prevent wild fires from destroying homes and property. These needles are often placed in regional landfills. The South Tahoe Refuse and Recycling Services alone has more than 4,340 tons of pine needles dumped at their facility annually. This large amount of biomass can be a potential energy source.
The focus ...
Channel Bar Morphology, Distribution, And Mining-Related Geochemistry In The Big River, St. Francois County, Missouri: Implications For Geomorphic Recovery, Lindsay Marie Olson
MSU Graduate Theses
Tailings releases associated with large-scale historical Pb mining in St. Francois County, Missouri resulted in system-wide contamination of Pb and excess sediment in the Big River. Previous studies have addressed basin and segment scale variability of the contaminants; however, little is known about reach and bar scale variability. This study addresses how mining sediment inputs influence bar form and geochemistry across a range of scales. Bar sediment samples were collected at 21 reaches and analyzed for particle size and geochemistry, while air photo analysis was used to evaluate channel morphology, bar type, and area. Bar area is initially low in ...
Phosphomolybdic Acid Catalysis Of Cellulose Hydrolysis, 2017 East Tennessee State University
Phosphomolybdic Acid Catalysis Of Cellulose Hydrolysis, Troy R. Dolmetsch
Undergraduate Honors Theses
Renewable sources such as cellulose derived biofuels are sought after in order to replace fossil fuel sources that are currently used to meet energy demands. Cellulose is a biological polymer composed of a chain of glucose molecules. Hydrolysis of cellulosic materials then has potential to serve as a source of renewable energy in the form of biofuels. The crystalline structure of cellulose is very stable, and current methods of catalyzed hydrolysis are inefficient for industrial application. This project explores the use of phosphomolybdic acid (PMA) in water to catalyze hydrolysis of microcrystalline cellulose. Temperature of hydrolysis was varied from 40 ...
Homogeneous Ligand-Centered Hydrogen Evolution And Hydrogen Oxidation : Exploiting Redox Non-Innocence To Drive Catalysis., 2017 University of Louisville
Homogeneous Ligand-Centered Hydrogen Evolution And Hydrogen Oxidation : Exploiting Redox Non-Innocence To Drive Catalysis., Andrew Z. Haddad
Electronic Theses and Dissertations
Hydrogen is a promising carbon-free fuel / energy carrier and is an essential building block for many industrial and agricultural processes. Rising energy demands have ignited interest in the development of carbon-free and carbon neutral energy sources. In this context, hydrogen is an attractive candidate—being energy-dense, carbon-free—and easily accessible through a two-electron reduction of water. Accordingly, many electrochemical homogeneous catalyst systems have been studied, with a focus on understanding the mechanism of hydrogen evolution proceeding through metal-hydride intermediates. However, there has been a renaissance in hydrogen evolution reaction (HER) catalyst design, with many groups implicating ligand redox non-innocence as ...
Functionalized Silica Gel For Adsorption Of Cesium From Solution, 2017 East Tennessee State University
Functionalized Silica Gel For Adsorption Of Cesium From Solution, Kenneth Marshall Seaton Iii
Electronic Theses and Dissertations
Mesoporous silica gel containing embedded phosphotungstic acid (PTA) was synthesized by sol-gel co-condensation of tetraethyl orthosilicate with PTA in acidic media. The obtained material had high Brunauer-Emmett-Teller Theory (BET) surface area and pore volume. A characteristic band of the Keggin structure of PTA was present in its FT-IR spectrum while its X-ray diffraction patterns were absent. This proved the embedding of PTA on a sub-molecular level and not as a second phase. Acidic sites were determined by neutralization with base in aprotic solvent, followed by titration of the remaining base with an acid. The material demonstrated high adsorption capacity of ...
Influence Of Histidine Residues, Ph And Charge Interactions On Membrane-Spanning Peptides, 2017 University of Arkansas, Fayetteville
Influence Of Histidine Residues, Ph And Charge Interactions On Membrane-Spanning Peptides, Ashley N. Henderson
Theses and Dissertations
Designed transmembrane peptides were employed for investigations of histidine residues within the hydrophobic environment of the lipid bilayer by means of oriented solid-state deuterium NMR spectroscopy. Using the model peptide GWALP23 sequence (GGALW(LA)6LWLAGA) as a host framework, the effects of single and double histidine mutations were explored. Replacement of leucine residue 12 to polar neutral histidine had little influence on the peptide average orientation, however under strongly acidic pH conditions in DOPC bilayers, the histidine becomes positively charged (pKa 2.5) and the GWALP23-H12 peptide exits the membrane and adopts a surface-bound orientation. Conversely, mutation of leucine 14 ...
Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman
Chemistry Faculty Publications
Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their ...
Spectrofluorometric Analysis Of Bisphenol-A In Drinking Water Bottles, 2017 Lynchburg College
Spectrofluorometric Analysis Of Bisphenol-A In Drinking Water Bottles, Jeff Brochetti
Student Scholar Showcase
Spectrofluorometric Analysis of Bisphenol-A in Drinking Water Bottles
Bisphenol-A (BPA) is of environmental concern due to its ability to act as an endocrine disruptor in humans and many other animals. In the food industry, BPA is widely used in the production of plastic bottles and plastic liners in aluminum cans. Over time, trace amounts of BPA can leach from the container and into the contents inside. A new method of testing for trace amount of BPA involved the formation of an inclusion complex with ß-Cyclodextrin. With the formation of the inclusion complex, it becomes much easier to analyze low concentrations ...
Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, 2017 University of Kentucky
Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali
Chemistry Faculty Publications
How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence ...
Multi-Scaled Approaches For Protecting Montana's Watersheds And Water Resources, 2017 University of Montana, Missoula
Multi-Scaled Approaches For Protecting Montana's Watersheds And Water Resources, Elizabeth Yoder
Graduate Student Portfolios
The central theme carried among my four portfolio pieces is: using scientific and governmental approaches to conserve watershed health. For the purposes of this portfolio, I define watershed health as a very general term that describes the state of water quantity and quality that is available for human and ecosystem needs in a watershed. I see each of my portfolio pieces focusing on a different scale and method (i.e., science or government, including different levels of government, local, state and federal) for conserving watershed health. My first portfolio piece reviews water quality degradation caused by pharmaceuticals and personal care ...
Polychlorinated Biphenyls, Polybrominated Biphenyls, Polychlorinated Dibenzo-P-Dioxins And Polychlorinated Dibenzofurans, 2017 United States Environmental Protection Agency, Research Triangle Park, NC.
Polychlorinated Biphenyls, Polybrominated Biphenyls, Polychlorinated Dibenzo-P-Dioxins And Polychlorinated Dibenzofurans, Prasada Rao S. Kodavanti, Joseph Valdez, Jae-Ho Yang, Margarita Curras Collazo, Bommanna G. Loganathan
Faculty & Staff Research and Creative Activity
Environmental contamination levels, human exposure, toxicokinetics, and health effects of PCBs, PBBs, PCDDs/PCDFs are discussed.