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2020

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Articles 61 - 90 of 104

Full-Text Articles in Environmental Chemistry

Using Electrocoagulation To Remove Perfluoroalkyl And Polyfluoroalkyl Substances (Pfas) From Contaminated Water, Amy Yanagida Apr 2020

Using Electrocoagulation To Remove Perfluoroalkyl And Polyfluoroalkyl Substances (Pfas) From Contaminated Water, Amy Yanagida

UCARE: Research Products

Perfluoroalkyl and Polyfluoroalkyl substances (PFAS) are a family of manmade chemicals that are used to improve the quality of several commercial products by making them resistant to heat, oil, stains, grease and water. Unfortunately, the chemical properties that make PFAS useful from an industrial perspective also make them mobile and recalcitrant once released into the environment. We used electrocoagulation to run a direct current through contaminated water to generate a zinc floc to precipiate PFAS out of water.

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Senior Project: An Investigative Study Into The Bacterial Contamination Of Little Black Creek, Margaret I. Brenneman Apr 2020

Senior Project: An Investigative Study Into The Bacterial Contamination Of Little Black Creek, Margaret I. Brenneman

Honors Projects

An investigation of Escherichia coli concentrations in a west Michigan stream was conducted to determine sources of fecal contamination that impact water quality. Little Black Creek (LBC) is located in Muskegon County and discharges into Lake Michigan at the P.J. Hoffmaster Campground Beach. Often referred to as an “indicator bacteria,” water contaminated with E. coli has a high probability to contain other enteric pathogens as well. Beach water testing in 2020 using Colilert-18 methods revealed E. coli levels of 579 cfu/100mL in the creek discharge area that exceeded total body contact criteria of 300 cfu/100mL. A follow-up study of the …

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A Public Health Perspective On Gen X Contamination In Drinking Water, Allison Stevens Apr 2020

A Public Health Perspective On Gen X Contamination In Drinking Water, Allison Stevens

Honors Capstone Enhancement Presentations

No abstract provided.

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Brown Carbon Production By Aqueous-Phase Interactions Of Glyoxal And So2, David O. De Haan, Kevin Jansen, Alec D. Rynaski, W. Ryan P. Sueme, Ashley K. Torkelson, Eric T. Czer, Alexander K. Kim, Michael A. Rafla, Audrey C. De Haan, Margaret A. Tolbert Mar 2020

Brown Carbon Production By Aqueous-Phase Interactions Of Glyoxal And So2, David O. De Haan, Kevin Jansen, Alec D. Rynaski, W. Ryan P. Sueme, Ashley K. Torkelson, Eric T. Czer, Alexander K. Kim, Michael A. Rafla, Audrey C. De Haan, Margaret A. Tolbert

Chemistry and Biochemistry: Faculty Scholarship

Oxalic acid and sulfate salts are major components of aerosol particles. Here, we explore the potential for their respective precursor species, glyoxal and SO2, to form atmospheric brown carbon via aqueous-phase reactions in a series of bulk aqueous and flow chamber aerosol experiments. In bulk aqueous solutions, UV- and visible-light-absorbing products are observed at pH 3–4 and 5–6, respectively, with small but detectable yields of hydroxyquinone and polyketone products formed, especially at pH 6. Hydroxymethanesulfonate (HMS), C2, and C3 sulfonates are major products detected by electrospray ionization mass spectrometry (ESI-MS) at pH 5. Past studies …

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Dissipation Of Benzobicyclon And Benzobicyclon Hydrolysate In A Louisiana Rice Field, Xavier Poole Mar 2020

Dissipation Of Benzobicyclon And Benzobicyclon Hydrolysate In A Louisiana Rice Field, Xavier Poole

LSU Master's Theses

Pesticide resistance in rice fields is an ongoing issue that has resulted in the development and use of pesticides with new modes of action. Benzobicyclon is the first registered hydroxyphenylpyruvate(HPPD)-inhibiting pesticide in the United States and has gained attention as a resistance management strategy to control weed pests in rice fields. Understanding the environmental fate and dissipation mechanisms of benzobicyclon is important due to the unique rotation of rice and crayfish in Louisiana on the same fields. Benzobicyclon persistence into the crayfish growing seasons may lead to unintended consequences for crayfish growth and production, assuming there is toxicity to crawfish. …

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Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman Mar 2020

Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Atmospheric methanethiol (MeSHa), dimethyl sulfide (DMSa) and acetone (acetonea) were measured over biologically productive frontal waters in the remote southwest Pacific Ocean in summertime 2012 during the Surface Ocean Aerosol Production (SOAP) voyage. MeSHa mixing ratios varied from below the detection limit (< 10 ppt) up to 65 ppt and were 3 %–36 % of parallel DMSa mixing ratios. MeSHa and DMSa were correlated over the voyage (R2=0.3, slope = 0.07) with a stronger correlation over a coccolithophore-dominated phytoplankton bloom (R2=0.5, slope 0.13). The diurnal cycle for MeSHa shows similar behaviour to DMSa with mixing ratios …

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Assessing The Ecological Risk Of Heavy Metal Sediment Contamination From Port Everglades Florida, Dimitri G. Giarikos, Laura White, Amy C. Hirons Mar 2020

Assessing The Ecological Risk Of Heavy Metal Sediment Contamination From Port Everglades Florida, Dimitri G. Giarikos, Laura White, Amy C. Hirons

SECLER Data

Port sediments are often contaminated with metals and organic compounds from anthropogenic sources. Port dredging can remobilize contaminated sediments, resulting in harmful impacts to the benthic community. Twelve sediment cores were collected from four Port Everglades, Florida sites and a control site; surface sediment was collected at two nearby coral reef sites. Sediment cores, sampled every 5 cm, were quantified for 14 heavy metals using induced coupled plasma mass spectrometry (ICPMS). Geo-accumulation index shows moderate-to-strong contamination of As and Mo in port sediments, and potential ecological risk indicates moderate-to-significantly high overall metal contamination. Arsenic port sediment concentrations exceed threshold effect …

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Synthesis And Fabrication Of Trimetallic (Ru-Mn Co) Catalyst Supported On Tio2 And Ni(Oh)2 Thin Films For Photoelectrochemical Applications, Che Mat Ahmad Nazeer Mar 2020

Synthesis And Fabrication Of Trimetallic (Ru-Mn Co) Catalyst Supported On Tio2 And Ni(Oh)2 Thin Films For Photoelectrochemical Applications, Che Mat Ahmad Nazeer

Student Works (2020-2029)

Anatase supported heterogeneous photocatalyst consisting of RuO2, MnO2 and Co3O4 (1:13:13 ratio) was synthesized by precipitation method. The film of the prepared catalyst was fabricated by electrophoretic deposition technique in an aqueous solution of 0.1 mM ammonia and tested for photoelectrocatalytic (PEC) oxidation of methanol in 0.1M KOH under visible light irradiation. The as-prepared photocatalyst was characterized by FTIR, UV–Vis, XRD, Raman spectroscopy, FESEM/EDX, TEM, BET, XPS and TPR. The PEC study by cyclic voltammetry indicates that the oxidation of methanol to CO2 and H2O upon exposure to visible light occurs between 400 and 800 nm. The smaller value of …

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Surface Reservoirs Dominate Dynamic Gas-Surface Partitioning Of Many Indoor Air Constituents, Chen Wang, Douglas B. Collins, Caleb Arata, Allen H. Goldstein, James M. Mattila, Delphine K. Farmer, Laura Ampollini, Peter F. Decarlo, Atila Novoselac, Marina E. Vance, William W. Nazaroff, Jonathan P.D. Abbatt Feb 2020

Surface Reservoirs Dominate Dynamic Gas-Surface Partitioning Of Many Indoor Air Constituents, Chen Wang, Douglas B. Collins, Caleb Arata, Allen H. Goldstein, James M. Mattila, Delphine K. Farmer, Laura Ampollini, Peter F. Decarlo, Atila Novoselac, Marina E. Vance, William W. Nazaroff, Jonathan P.D. Abbatt

Faculty Journal Articles

Human health is affected by indoor air quality. One distinctive aspect of the indoor environment is its very large surface area that acts as a poorly characterized sink and source of gas-phase chemicals. In this work, air-surface interactions of 19 common indoor air contaminants with diverse properties and sources were monitored in a house using fast-response, on-line mass spectrometric and spectroscopic methods. Enhanced-ventilation experiments demonstrate that most of the contaminants reside in the surface reservoirs and not, as expected, in the gas phase. They participate in rapid air-surface partitioning that is much faster than air exchange. Phase distribution calculations are …

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Assessment Of Soil Protein And Refractory Soil Organic Matter Across Two Chronosequences Of Newly Developing Marshes In Coastal Louisiana, Usa, Stuart Alexander Mcclellan Feb 2020

Assessment Of Soil Protein And Refractory Soil Organic Matter Across Two Chronosequences Of Newly Developing Marshes In Coastal Louisiana, Usa, Stuart Alexander Mcclellan

LSU Doctoral Dissertations

The impacts of sea-level rise and hydrologic manipulation are threatening the stability of coastal marshes throughout the world, thereby increasing the potential for re-mineralization of soil organic matter (SOM) in these systems. Such threats have prompted marsh restoration efforts, particularly in coastal Louisiana, yet it is unclear how the slowly decomposing (refractory) and quickly decomposing (labile) fractions of SOM may be differentially affected by different approaches to marsh restoration. Additionally, otherwise labile compounds may accumulate in the soil via a range of protective mechanisms, including rapid burial and association with organic compounds that are thought to enhance soil aggregation, such …

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Analysis Of Organochlorine Pesticides Levels In Irrigation Water From Various Water Sources Across Egypt, Omar Tarek Khairy Jan 2020

Analysis Of Organochlorine Pesticides Levels In Irrigation Water From Various Water Sources Across Egypt, Omar Tarek Khairy

Theses and Dissertations

Organochlorine pesticides are extensively used in agriculture to cope with the world’s increasing population and demands for nutrition. This class of pesticides poses a serious risk to human health upon chronic exposure to elevated levels. Determination of organochlorine pesticides levels in water has been extensively covered in literature in Egypt and other parts of the world. The need for up-to date data and statistical information regarding the levels of organochlorine pesticides in water is ever increasing. These compounds, although a lot have been prohibited from use decades ago, can still be detected in trace levels in water due to their …

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Air/Sea Transfer Of Highly Soluble Gases Over Coastal Waters, J. G. Porter, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman Jan 2020

Air/Sea Transfer Of Highly Soluble Gases Over Coastal Waters, J. G. Porter, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The deposition of soluble trace gases to the sea surface is not well studied due to a lack of flux measurements over the ocean. Here we report simultaneous air/sea eddy covariance flux measurements of water vapor, sulfur dioxide (SO2), and momentum from a coastal North Atlantic pier. Gas transfer velocities were on average about 20% lower for SO2 than for H2O. This difference is attributed to the difference in molecular diffusivity between the two molecules (D SO 2/D H 2O = 0.5), in reasonable agreement with bulk parameterizations in air/sea gas …

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Anoxic Conditions Maintained High Phosphorus Sorption In Humid Tropical Forest Soils, Yang Lin, Avner Gross, Christine S. O'Connell, Whendee L. Silver Jan 2020

Anoxic Conditions Maintained High Phosphorus Sorption In Humid Tropical Forest Soils, Yang Lin, Avner Gross, Christine S. O'Connell, Whendee L. Silver

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The strong phosphorus (P) sorption capacity of iron (Fe) and aluminum (Al) minerals in highly weathered, acidic soils of humid tropical forests is generally assumed to be an important driver of P limitation to plants and microbial activity in these ecosystems. Humid tropical forest soils often experience fluctuating redox conditions that reduce Fe and raise pH. It is commonly thought that Fe reduction generally decreases the capacity and strength of P sorption. Here we examined the effects of 14 d oxic and anoxic incubations on soil P sorption dynamics in humid tropical forest soils from Puerto Rico. Contrary to the …

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Correlation Between Ocean Acidification And Zooplankton In The South Pacific Gyre, Samuel Noonan, Rachel Scudder Jan 2020

Correlation Between Ocean Acidification And Zooplankton In The South Pacific Gyre, Samuel Noonan, Rachel Scudder

DU Undergraduate Research Journal Archive

The South Pacific Gyre is a naturally occurring carbon sink, meaning that it absorbs atmospheric carbon dioxide by dissolving it into the moving surface water. The dissolution of CO2 level will dictate the water’s acidic levels a larger the concentration of dissolved CO2 is known to increase the salt water’s acidity. A great amount of the ocean’s biomass is composed of calcifying organisms, which produce tests or shells made from calcium carbonate CaCO3.The goal of our project is to determine if there is a correlation between the water acidity across various locations, as we sailed through the South Pacific gyre …

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Data On Gc/Ms Elution Profile, 1h And 13c Nmr Spectra Of 1-, 3-, And 6-Nitrobenzo[A]Pyrenes, Kefa Karimu Onchoke Jan 2020

Data On Gc/Ms Elution Profile, 1h And 13c Nmr Spectra Of 1-, 3-, And 6-Nitrobenzo[A]Pyrenes, Kefa Karimu Onchoke

Faculty Publications

The data presented in this article is related to the research article entitled, “13C NMR Chemical Shift Assignments of Nitrated Benzo[a]pyrenes based on Two-dimensional Techniques and DFT/GIAO Calculations”, Kefa K. Onchoke, PeerJ., . The NMR spectral profiles of nitrated benzo[a]pyrenes is presented. Further, the article describes elution profiles of 1-, 3- and 6-NBaP, the acquisition of 1H and 13C NMR data and the J-Coupling constants (which are useful for the assignment of peaks via 2D HMQC and HMBC techniques). The data presented is useful for developing structure-activity relationships for other nitrated polycyclic aromatic hydrocarbons (NPAHs)

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Green Chemistry: The Oxidation Of Benzaldehyde Using Atmospheric Oxygen And N-Heterocyclic Carbenes As Catalysts, Alex Brody, John Morgan Jan 2020

Green Chemistry: The Oxidation Of Benzaldehyde Using Atmospheric Oxygen And N-Heterocyclic Carbenes As Catalysts, Alex Brody, John Morgan

Student Research Poster Presentations 2020

Oxidation is a vital process in organic and biochemical reactions. In particular, the oxidation of aromatic aldehydes to carboxylic acids and esters is a vital process used in many different environments. Benzaldehyde is one common subject of this type of reaction, used in the synthesis of benzoic acid and benzoate derivatives. Unfortunately, the industrial synthesis of these compounds uses harmful heavy metal oxidants such as Chromium(VI) and Manganese(VII), which are very harmful to the environment. We proposed to eliminate these pollutants by using atmospheric oxygen and an organic catalyst in a solvent free reaction. This reaction would then be microwaved …

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Advancement Of Predictive Modeling Of Zeta Potentials (Ζ) In Metal Oxide Nanoparticles With Correlation Intensity Index (Cii), Andrey A. Toropov, Natalia Sizochenko, Alla P. Toropova, Danuta Leszczynska, Jerzy Leszczynski Jan 2020

Advancement Of Predictive Modeling Of Zeta Potentials (Ζ) In Metal Oxide Nanoparticles With Correlation Intensity Index (Cii), Andrey A. Toropov, Natalia Sizochenko, Alla P. Toropova, Danuta Leszczynska, Jerzy Leszczynski

Articles

It was expected that index of the ideality of correlation (IIC) and correlation intensity index (CII) could be used as possible tools to improve the predictive power of the quantitative model for zeta potential of nanoparticles. In this paper, we test how the statistical quality of quantitative structure-activity models for zeta potentials (ζ, a common measurement that reflects surface charge and stability of nanomaterial) could be improved with the use of these two indexes. Our hypothesis was tested using the benchmark data set that consists of 87 measurements of zeta potentials in water. We used quasi-SMILES molecular representation to take …

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In Situ Cultivation Of Potential Pah Degrading Bacteria From Coastal Sediment, Kyle Benkel Jan 2020

In Situ Cultivation Of Potential Pah Degrading Bacteria From Coastal Sediment, Kyle Benkel

Honors Undergraduate Theses

Oil spills can introduce potentially carcinogenic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), into coastal environments. Bioremediation uses the natural microorganisms in the environment to remove these pollutants. Traditional studies of these organisms are limited in the types of bacteria isolated due to the limitations of traditional culturing methods. In this study, diffusion chambers were used to culture and isolate potential PAH degrading bacteria from the coastal sediment obtained from the Chandeleur Islands. The diffusion chambers trapped bacteria in agar that contained 1 ppm benzo[a]pyrene. The bacteria were isolated from the diffusion chambers, and the 16S rRNA gene was sequenced …

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Characterization Of Coal Particles In The Soil Of A Former Rail Yard And Urban Brownfield: Liberty State Park, Jersey City (Nj), Usa, Diane F. Hagmann, Michael A. Kruge, Nina M. Goodey, Jennifer Adams Krumins Jan 2020

Characterization Of Coal Particles In The Soil Of A Former Rail Yard And Urban Brownfield: Liberty State Park, Jersey City (Nj), Usa, Diane F. Hagmann, Michael A. Kruge, Nina M. Goodey, Jennifer Adams Krumins

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

From the 1850's until the 1960's, the Central Railroad of New Jersey was among several major railways shipping anthracite and bituminous coal to the New York City area, transferring coal from railcar to barge at its extensive rail yard and port facility in Jersey City. The 490 ha Liberty State Park was developed on the site after the rail yard closed, but a ca. 100 ha brownfield zone within the park remains off limits to visitors pending future remediation. As part of an environmental forensic and industrial archeological investigation of this zone, the present study characterizes anthracite and bituminous coal …

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Ni-Au Anodic Nano-Electrocatalyst For Direct Glucose Fuel Cells, Islam M. Al-Akraa, Aya S. Abdulhalim Eng, Yassr M. Asal Mr, Ahmad M. Mohammad Prof Jan 2020

Ni-Au Anodic Nano-Electrocatalyst For Direct Glucose Fuel Cells, Islam M. Al-Akraa, Aya S. Abdulhalim Eng, Yassr M. Asal Mr, Ahmad M. Mohammad Prof

Chemical Engineering

This study aims at the sequential assembling of a nickel oxide (NiOx: cauliflower-like nanostructure, 90 nm) and gold (Au; spherical, 95 nm in an average particle size) onto the GC surface nanocatalyst on a glassy carbon (GC) electrode (will be abbreviated as Ni-Au/GC) for the glucose electro−oxidation (GO); the principal anodic reaction in the direct glucose fuel cells (DGFCs). The charge of the Ni deposition on the GC surface (will be abbreviated as Ni/GC electrode) was initially optimized to obtain the highest catalytic activity toward GO which attained at (339.8 Ag−1) by applying 15 mC in the Ni deposition. Yet, …

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Volcanic Impact On Stratospheric Chlorine Chemistry And Perchlorate Formation: Evidence From Ice Cores, Joshua Andrew Kennedy Jan 2020

Volcanic Impact On Stratospheric Chlorine Chemistry And Perchlorate Formation: Evidence From Ice Cores, Joshua Andrew Kennedy

Electronic Theses and Dissertations

Perchlorate, suspected to be chemically formed in both the troposphere and stratosphere, has been recently measured in Arctic snow and ice cores. These comprise both discontinuous snow and ice cores from the Canadian Arctic and a continuous record of perchlorate was compiled from an analysis of Greenland ice cores. While the background perchlorate concentration typically is very low, a few spikes in concentration coinciding with deposition of volcanic sulfate were observed in the Greenland record, suggesting that perchlorate levels in the atmosphere may be impacted by volcanic eruptions. As of yet, no work has been done to investigate the connection …

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Microplastic Fragment And Fiber Contamination Of Beach Sediments From Selected Sites In Virginia And North Carolina, Usa, Gabrielle Z. Dodson, A. Katrina Shotorban, Patrick G. Hatcher, Derek Waggoner, Sutapa Ghosal, Nora Noffke Jan 2020

Microplastic Fragment And Fiber Contamination Of Beach Sediments From Selected Sites In Virginia And North Carolina, Usa, Gabrielle Z. Dodson, A. Katrina Shotorban, Patrick G. Hatcher, Derek Waggoner, Sutapa Ghosal, Nora Noffke

OES Faculty Publications

Microplastic particles (<5 >mm) constitute a growing pollution problem within coastal environments. This study investigated the microplastic presence of estuarine and barrier island beaches in the states of Virginia and North Carolina, USA. Seventeen sediment cores were collected at four study sites and initially tested for microplastic presence by pyrolysis-gas chromatography–mass spectrometry. For the extraction, microplastic particles were first separated from the sediment using a high-density cesium chloride solution (1.88 g/mL). In a second step, an oil extraction collected the remaining microplastic particles of higher densities. Under the light microscope, the extracted microplastic particles were classified based on their morphologies …

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Enhanced Glucose Electrooxidation At Ni-Cu Binary Oxide Nanocatalyst, Islam M. Al-Akraa, Mahmoud M. Abouzaid Eng, Yaser M. Asal Mr, Ahmad M. Mohammad Prof Jan 2020

Enhanced Glucose Electrooxidation At Ni-Cu Binary Oxide Nanocatalyst, Islam M. Al-Akraa, Mahmoud M. Abouzaid Eng, Yaser M. Asal Mr, Ahmad M. Mohammad Prof

Chemical Engineering

The aim of this study is to fabricate a nickel (NiOx) and copper (CuOx) oxide nanocatalyst on a glassy carbon (GC) electrode (will be abbreviated as Ni-Cu/GC) for glucose oxidation (GO). A sequential electrodepositon mode was applied to assemble NiOx and CuOx in the fabrication scheme. The optimization of Ni loading on the GC surface (will be abbreviated as Ni/GC electrode) was achieved first to attain the maximum catalytic efficiency in terms of the specific current toward GO. This (409 Ag1)was obtained by applying 15 mC/cm2 in the deposition of Ni. However, unfortunately the NiOx/GC could not support a long-term …

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Development Of Novel Adsorbent For Industrial Waste Water Treatment, Islam M. Al-Akraa, Hassan M. Shehata Eng, Dalia A. Ali Eng., Hoda A. Elsawy Dr Jan 2020

Development Of Novel Adsorbent For Industrial Waste Water Treatment, Islam M. Al-Akraa, Hassan M. Shehata Eng, Dalia A. Ali Eng., Hoda A. Elsawy Dr

Chemical Engineering

The main objective of this research project is to perform some experimental procedures to inform the ability of the novel adsorbent used in this project. The chemical modification of the adsorbent is the chemical oxidation of pure powder chitosan using some specific redox pairs which are potassium dichromate and sodium bisulphite. After preparing the modified chitosan, there are some parameters that must be discussed during the adsorption process. The first parameter is the time parameter, showing experimentally the optimum time for adsorption under certain conditions by collecting values of absorbance and concentration of thymol blue adsorbed after the process from …

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A Model Experiment To Investigate The Possibility Of Glyphosate Contamination In St. Kitts And Nevis, Winston Fu Jan 2020

A Model Experiment To Investigate The Possibility Of Glyphosate Contamination In St. Kitts And Nevis, Winston Fu

Honors Undergraduate Theses

Glyphosate is a broad-spectrum herbicide that is used globally to combat the spread of weeds among crops. Not all countries around the world have been using the herbicide. For example, island countries such as Dominica and St. Kitts and Nevis do not use the herbicide on their crops. However, St. Kitts and Nevis imports food and other agricultural products from around the world, leading to the hypothesis that glyphosate is contaminating the soil through those imported products. The aim of this research project was to determine if glyphosate is present in the island country of St. Kitts and Nevis. A …

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Seaweed As A Carrier For Microplastics, Stephanie M. Rodriguez Jan 2020

Seaweed As A Carrier For Microplastics, Stephanie M. Rodriguez

Honors Undergraduate Theses

Analysis of seaweed as a vector for microplastics is an integral part of understanding the formation and deposition of micro-sized plastic waste in seawater. The project itself originated due to the influx of seaweed (and mismanaged plastic waste) residing on the shores of St. Kitts and Nevis and the constant deposition of plastic pollution intertwined within the seaweed. The natural occurrence of the two together lead to the consideration of fragmented plastics remaining on the seaweed. The objective of this research is to stain, identify, and quantify the concentration of microplastics sourced from both store-bought and environmental seaweed samples. A …

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Microdialysis: A Method For Quantifying In Situ Nitrogen Fluxes In Soil Microsites, Srusti Maddala, Mary C. Savin, Julie A. Stenken, Lisa S. Wood Jan 2020

Microdialysis: A Method For Quantifying In Situ Nitrogen Fluxes In Soil Microsites, Srusti Maddala, Mary C. Savin, Julie A. Stenken, Lisa S. Wood

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has recently been recognized as a candidate for monitoring chemical changes in the rhizosphere. The information it provides about nutrient diffusion may improve nitrogen use efficiency, leading to enhanced management and success of restoration projects. The objective of this study was to determine the efficacy of microdialysis sampling to quantify the relative recoveries (RR%) of nitrate-N and ammonium-N, the two inorganic nitrogen compounds typically found in soil. The effects of microdialysis flow rate, sample medium concentration, and the presence of both analytes in solution on the relative recoveries obtained from …

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Molecular Nature Of Marine Particulate Organic Iron-Carrying Moieties Revealed By Electrospray Ionization Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (Esi-Fticrms), Chen Xu, Peng Lin, Luni Sun, Hongmei Chen, Wei Xing, Manoj Kamalanathan, Patrick G. Hatcher, Maureen H. Conte, Antonietta Quigg, Peter H. Santschi Jan 2020

Molecular Nature Of Marine Particulate Organic Iron-Carrying Moieties Revealed By Electrospray Ionization Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (Esi-Fticrms), Chen Xu, Peng Lin, Luni Sun, Hongmei Chen, Wei Xing, Manoj Kamalanathan, Patrick G. Hatcher, Maureen H. Conte, Antonietta Quigg, Peter H. Santschi

Chemistry & Biochemistry Faculty Publications

Marine sinking particulate organic matter (POM), acting as a link between surface primary production and burial of organic matter in marine sediments, undergoes a variety of physical and biochemical alterations on its way to the deep ocean, resulting in an increase in its un-characterizable proportion with diagenesis. Further, the binding ligands in POM for iron, an essential nutrient to marine life and tightly coupled with organic matter, has rarely been studied. In the current study, we employed an approach combining sequential extraction with ultrahigh resolution mass spectrometry (ESI-FTICRMS), in order to explore and unravel the chemical characteristics of organic matter …

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Nrlmsis 2.0: A Whole-Atmosphere Empirical Model Of Temperature And Neutral Species Densities, J. T. Emmert, D. P. Drob, J. M. Picone, D. E. Siskind, M. Jones Jr., M. G. Mlynczak, Peter F. Bernath, X. Chu, E. Doornbos, B. Funke, L. P. Goncharenko, M. E. Hervig, M. J. Schwartz, P. E. Sheese, F. Vargas, B. P. Williams, T. Yuan Jan 2020

Nrlmsis 2.0: A Whole-Atmosphere Empirical Model Of Temperature And Neutral Species Densities, J. T. Emmert, D. P. Drob, J. M. Picone, D. E. Siskind, M. Jones Jr., M. G. Mlynczak, Peter F. Bernath, X. Chu, E. Doornbos, B. Funke, L. P. Goncharenko, M. E. Hervig, M. J. Schwartz, P. E. Sheese, F. Vargas, B. P. Williams, T. Yuan

Chemistry & Biochemistry Faculty Publications

NRLMSIS® 2.0 is an empirical atmospheric model that extends from the ground to the exobase and describes the average observed behavior of temperature, eight species densities, and mass density via a parametric analytic formulation. The model inputs are location, day of year, time of day, solar activity, and geomagnetic activity. NRLMSIS 2.0 is a major, reformulated upgrade of the previous version, NRLMSISE-00. The model now couples thermospheric species densities to the entire column, via an effective mass profile that transitions each species from the fully mixed region below ~70 km altitude to the diffusively separated region above ~200 km. Other …

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Effect Of The Electrodeposition Potential Of Platinum On The Catalytic Activity Of A Pt/Gc Catalyst Toward Formic Acid Electro−Oxidation, Islam M. Al-Akraa, Bilquis A. Al-Qodami Ms., Ahmad M. Mohammad Prof Jan 2020

Effect Of The Electrodeposition Potential Of Platinum On The Catalytic Activity Of A Pt/Gc Catalyst Toward Formic Acid Electro−Oxidation, Islam M. Al-Akraa, Bilquis A. Al-Qodami Ms., Ahmad M. Mohammad Prof

Chemical Engineering

The electrocatalytic activity of platinum (Pt)–modified glassy carbon (GC) (referred as Pt/GC) electrodes toward the formic acid electro−oxidation (FAO) was investigated. The Pt deposition on the GC substrate was carried out by a potentiostatic technique at different potentials (from 0.2 V to −0.2 V vs. Hg/Hg2Cl2/KCl (sat.) reference electrode) and the corresponding influence on the catalytic activity toward FAO was monitored. The electrocatalytic inspection revealed a potential role for the Pt deposition potential in boosting the catalytic efficiency of the catalyst toward FAO and further in mitigating the CO poisoning that eventually deactivate the catalyst. Interestingly, the highest activity toward …

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