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Environmental Chemistry Commons

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Environmental Sciences

2020

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Articles 1 - 28 of 28

Full-Text Articles in Environmental Chemistry

Accurate Quantitation Of Hexavalent Chromium For Reference Standard Certification And Quality Control Testing Using Speciated Isotope Dilution Mass Spectrometry, James E. Henderson Dec 2020

Accurate Quantitation Of Hexavalent Chromium For Reference Standard Certification And Quality Control Testing Using Speciated Isotope Dilution Mass Spectrometry, James E. Henderson

Electronic Theses and Dissertations

The ability to perform accurate, repeatable, and defensible elemental and molecular speciated analysis is immensely significant for measurements that support human health, environmental science, and industry. This is especially true since trivalent chromium [Cr(III)] is necessary for proper nutrition, while hexavalent chromium [Cr(VI)] is extremely toxic, genotoxic, and carcinogenic. The main challenges associated with speciated analysis are related to reactive species that are continuously transformed or converted to other species during sample processing. Accurate determination of Cr(III) and Cr(VI) species require a method that is capable of monitoring and correcting for interconversion, bias, and instrumental error. Traditional quantitative methods, such …


Eelgrass (Zostera Marina) Population Decline In Morro Bay, Ca: A Meta-Analysis Of Herbicide Application In San Luis Obispo County And Morro Bay Watershed, Tyler King Sinnott Dec 2020

Eelgrass (Zostera Marina) Population Decline In Morro Bay, Ca: A Meta-Analysis Of Herbicide Application In San Luis Obispo County And Morro Bay Watershed, Tyler King Sinnott

Master's Theses

The endemic eelgrass (Zostera marina) community of Morro Bay Estuary, located on the central coast of California, has experienced an estimated decline of 95% in occupied area (reduction of 344 acres to 20 acres) from 2008 to 2017 for reasons that are not yet definitively clear. One possible driver of degradation that has yet to be investigated is the role of herbicides from agricultural fields in the watershed that feeds into the estuary. Thus, the primary research goal of this project was to better understand temporal and spatial trends of herbicide use within the context of San Luis …


Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan Dec 2020

Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4·6H2O) is an understudied material that can be created from Pcontaining wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple super phosphate (TSP) on corn (Zea mays) and soybean (Glycine max) response in a 79-day greenhouse pot …


Algal Biomarkers As A Proxy For Pco2: Constraints From Late Quaternary Sapropels In The Eastern Mediterranean, Caitlyn R. Witkowski, Marcel T.J. Van Der Meer, Brian Blais, Jaap S. Sinninghe Damsté, Stefan Schouten Sep 2020

Algal Biomarkers As A Proxy For Pco2: Constraints From Late Quaternary Sapropels In The Eastern Mediterranean, Caitlyn R. Witkowski, Marcel T.J. Van Der Meer, Brian Blais, Jaap S. Sinninghe Damsté, Stefan Schouten

Science and Technology Department Faculty Journal Articles

Records of carbon dioxide concentrations (partial pressure expressed as pCO2) over Earth’s history provide trends that are critical to understand our changing world. To better constrain pCO2 estimations, here we test organic pCO2 proxies against the direct measurements of pCO2 recorded in ice cores. Based on the concept of stable carbon isotopic fractionation due to photosynthetic CO2 fixation (Ɛp), we use the stable carbon isotopic composition (δ13C) of the recently proposed biomarker phytol (from all photoautotrophs), as well as the conventionally used alkenone biomarkers (from specific species) for comparison, to reconstruct pCO2 over several Quaternary …


Annual Concentration And Flux Of Non-Sea-Salt Sulfate In The Wais Divide Ice Core (Wdc) For The Last 11,000 Years, Jihong Cole-Dai Sep 2020

Annual Concentration And Flux Of Non-Sea-Salt Sulfate In The Wais Divide Ice Core (Wdc) For The Last 11,000 Years, Jihong Cole-Dai

Ice Core and Environmental Chemistry Lab Datasets and Publications

Annual concentration and flux of non-sea-slat sulfate in the WAIS Divide ice core (WDC) for the last 11,000 years.


Long Term Air Quality Analysis In Reference To Thermal Power Plants Using Satellite Data In Singrauli Region, India, H. K. Romana, Ramesh P. Singh, D. P. Shukla Aug 2020

Long Term Air Quality Analysis In Reference To Thermal Power Plants Using Satellite Data In Singrauli Region, India, H. K. Romana, Ramesh P. Singh, D. P. Shukla

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The exponentially growing population and related anthropogenic activities have led to modifications in local environment. The change in local environment, evolving pattern of land use, concentrations of greenhouse gases and aerosols alter the energy balance of our climate system. This alteration in climate is leading to pre-mature deaths worldwide. This study analyses the air quality of Singrauli region, Madhya Pradesh, India for the past 15 years. Otherwise known as Urjanchal “the energy capital” of India has been declared as critically polluted by CPCB. The study provides an updated list of thermal power plants in the study area and their emission …


The Legacy Of Mining In Southwest Missouri: Past And Present Conditions Of The Tri-State Mining District, Anastasia M C Mcclanahan Aug 2020

The Legacy Of Mining In Southwest Missouri: Past And Present Conditions Of The Tri-State Mining District, Anastasia M C Mcclanahan

MSU Graduate Theses

The historic Tri-State Mining District (TSMD) of southwestern Missouri, southeastern Kansas, and northeastern Oklahoma has a history of lead and zinc mining that extended over a hundred years. During the district’s peak production period, the TSMD was one of the world’s largest producers of lead and zinc. The mining activities in the TSMD produced economic growth that supported the local communities and were essential to the victory of the Allied Forces during World War I and World War II. Beginning in the 1920s, the mining activities in the district slowly began to cease due to depletion of metal ores and …


Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates Jul 2020

Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates

LSU Master's Theses

Man-made levees along the lower Mississippi River prevent delivery of sediment from building and maintaining Louisiana’s coastal wetlands. The Mid-Barataria sediment diversions is designed to reintroduce Mississippi River water, sediment, and nutrients into the sediment-starved Barataria Basin. Phosphorus (P) is an important macronutrient for regulating primary production in coastal marine ecosystems. Wetlands can serve as a sink or source for phosphorus to the overlying water column through various retention and release processes, dependent on concentration. Louisiana coastal systems can be phosphorus limited due to much higher concentrations of bioavailable Nitrogen in river water. The high soluble molar N:P ( >50:1) …


Challenges In Quantifying Air‐Water Carbon Dioxide Flux Using Estuarine Water Quality Data: Case Study For Chesapeake Bay, Maria Herrmann, Raymond G. Najjar, Fei Da, Jaclyn R. Friedman, Marjorie A. M. Friedrichs, Sreece Goldberger, Alana Menendez, Elizabeth H. Shadwick, Edward G. Stets, Pierre St-Laurent May 2020

Challenges In Quantifying Air‐Water Carbon Dioxide Flux Using Estuarine Water Quality Data: Case Study For Chesapeake Bay, Maria Herrmann, Raymond G. Najjar, Fei Da, Jaclyn R. Friedman, Marjorie A. M. Friedrichs, Sreece Goldberger, Alana Menendez, Elizabeth H. Shadwick, Edward G. Stets, Pierre St-Laurent

Publications and Research

Estuaries play an uncertain but potentially important role in the global carbon cycle via CO2 outgassing. The uncertainty mainly stems from the paucity of studies that document the full spatial and temporal variability of estuarine surface water partial pressure of carbon dioxide ( pCO2). Here, we explore the potential of utilizing the abundance of pH data from historical water quality monitoring programs to fill the data void via a case study of the mainstem Chesapeake Bay (eastern United States). We calculate pCO2 and the air-water CO2 flux at monthly resolution from 1998 to …


Heavy Metals In Particulate Matter In Spokane County, Delaney M. White May 2020

Heavy Metals In Particulate Matter In Spokane County, Delaney M. White

2020 Symposium Posters

Heavy metals in particulate matter (e.g., dust) have multiple negative health ramifications for humans including cancer, infertility, and reduced lung function. The Spokane Regional Clean Air Agency (SRCAA) has seven air quality monitoring stations around Spokane County to measure total levels of PM2.5 (particles with a diameter less than 2.5 micrometers) and PM10 (particles with a diameter less than 10 micrometers). For comparison, the width of a human hair is between 50 and 70 micrometers. The objective of this research is to examine the heavy metal composition of the particulate matter including elements such as lead, copper, and zinc. We …


Massive Peatland Carbon Banks Vulnerable To Rising Temperatures, A. M. Hopple, R. M. Wilson, M. Kolton, Cassandra A. Zalman, J. P. Chanton, J. Kostka, P. J. Hanson, Jason K. Keller, S. D. Bridgham May 2020

Massive Peatland Carbon Banks Vulnerable To Rising Temperatures, A. M. Hopple, R. M. Wilson, M. Kolton, Cassandra A. Zalman, J. P. Chanton, J. Kostka, P. J. Hanson, Jason K. Keller, S. D. Bridgham

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands contain one-third of the world’s soil carbon (C). If destabilized, decomposition of this vast C bank could accelerate climate warming; however, the likelihood of this outcome remains unknown. Here, we examine peatland C stability through five years of whole-ecosystem warming and two years of elevated atmospheric carbon dioxide concentrations (eCO2). Warming exponentially increased methane (CH4) emissions and enhanced CH4 production rates throughout the entire soil profile; although surface CH4 production rates remain much greater than those at depth. Additionally, older deeper C sources played a larger role in decomposition following prolonged warming. Most …


Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa May 2020

Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Primary productivity (PP) has been recently investigated using remote sensing-based models over quite limited geographical areas of the Red Sea. This work sheds light on how phytoplankton and primary production would react to the effects of global warming in the extreme environment of the Red Sea and, hence, illuminates how similar regions may behave in the context of climate variability. study focuses on using satellite observations to conduct an intercomparison of three net primary production (NPP) models--the vertically generalized production model (VGPM), the Eppley-VGPM, and the carbon-based production model (CbPM)--produced over the Red Sea domain for the 1998-2018 time period. …


In Situ Plant Uptake Of Excess Nutrients And Consequential Alteration Of Rhizosphere Dynamics, Srusti Maddala May 2020

In Situ Plant Uptake Of Excess Nutrients And Consequential Alteration Of Rhizosphere Dynamics, Srusti Maddala

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The use of phytoremediation in ecological remediation projects has numerous benefits including soil stabilization and nutrient uptake. Recently, microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has been recognized as a candidate for monitoring chemical changes in the rhizosphere. The real-time, in situ data it provides about nutrient diffusion may improve the management and success of restoration projects. Therefore, the objective of this study was to employ the technique of microdialysis in the novel application of quantifying the diffusive flux of inorganic nitrogen compounds in the rhizosphere of native plants of Arkansas. The microdialysis technique was first optimized …


183— Cannabis Sativa: Pretreatment And Fiber Content Analysis, Dina Bú, Arianna Soriano, Sofia Kostrinsky, Sarah Schmidlin, Barnabas Gikonyo Apr 2020

183— Cannabis Sativa: Pretreatment And Fiber Content Analysis, Dina Bú, Arianna Soriano, Sofia Kostrinsky, Sarah Schmidlin, Barnabas Gikonyo

GREAT Day Posters

Cannabis Sativa commonly known as hemp, is one of the fastest growing plants whose refined products have immense commercial value. Refined hemp is included in various products: biofuels, biodegradable plastics, textiles, dietary supplements, paper, clothing and much more. Hemp fibers are also used in construction and manufacturing applications as a way to strengthen composite products. These qualities make hemp a high yielding, sustainable, and environmentally friendly crop with the potential to yield valuable raw materials for a large number of applications. Our research evaluates the pretreatment of hemp and the comparative analysis of the fiber content thereof. Our goal is …


Surveillance Of Microplastic Pollution In Central Virginia Freshwater Ecosystems, Alexandra Reddy Apr 2020

Surveillance Of Microplastic Pollution In Central Virginia Freshwater Ecosystems, Alexandra Reddy

Senior Honors Theses

Aquatic organisms often mistake microplastic particulates (MP) as food and inadvertently ingest the particulates, which can biomagnify through the food chain. While MP ingestion is well-researched in the marine environment, little is known about microplastics in freshwater  ecosystems. This project explores MP occurrence in an ecologically significant freshwater invertebrate: crayfish. Crayfish from two Central Virginia streams are collected to identify MP in the digestive tracts and gill filaments, and characterize the MP using analytical chemistry techniques. It was determined that MP were present in the digestive tracts and gill filaments of crayfish collected from both streams, and that MP frequency …


Mercury And Other Trace Metal Analysis In Bat Guano, Amanda Lee Houchens Apr 2020

Mercury And Other Trace Metal Analysis In Bat Guano, Amanda Lee Houchens

Masters Theses & Specialist Projects

Heavy metal pollution in the environment pose risks to ecosystems and the populations that reside in them. Mercury, lead, and cadmium negatively impact humans by way of neurological disorders, various cancers, and damage the reproductive organs, kidneys, and lungs. Bats have been studied as a bioindicator species to identify possibly elevated levels of these metals in the environment. Previous studies have identified correlation between metal concentrations within bat tissues and fur. Many bat species are endangered or at risk due to white-nose syndrome so collection of tissues and fur for analysis can impose stress on bat colonies. This study investigates …


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.


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. …


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 …


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 …


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)


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 …


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 …


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 …


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 …


Reconstructing Hydrologic Conditions And Metals Supplied By The Peace River To The Peace-Athabasca Delta, Jelle André Faber Jan 2020

Reconstructing Hydrologic Conditions And Metals Supplied By The Peace River To The Peace-Athabasca Delta, Jelle André Faber

Theses and Dissertations (Comprehensive)

The Peace-Athabasca Delta (PAD) in northern Alberta, Canada, is recognized internationally for its ecological, historical, and cultural significance. The delta is mostly within Wood Buffalo National Park, a UNESCO World Heritage Site, and is a Ramsar Wetland of International Importance. The construction of the WAC Bennett Dam (1967) and the Site C Dam (ongoing, 2024) on the Peace River, and expansion of the Alberta Oil Sands industry along the Athabasca River have raised concerns over water quantity and quality in the delta. When industry operations began, effective monitoring had not been implemented. Consequently, pre-industrial reference conditions are unknown and can …


Applications Of Drones In Atmospheric Chemistry, Travis J. Schuyler Jan 2020

Applications Of Drones In Atmospheric Chemistry, Travis J. Schuyler

Theses and Dissertations--Chemistry

The emission of greenhouse gases (GHGs) has changed the composition of the atmosphere during the Anthropocene. A major technical and scientific challenge is quantifying the resulting fugitive trace gas fluxes under variable meteorological conditions. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating contributions of different processes to radiative forcing. Therefore, the adverse environmental and health effects of undetected gas leaks motivates new methods of detecting, characterizing, and quantifying plumes of fugitive trace gases. Currently, there is no mobile platform able to quantify trace gases at altitudes(UASs), or drones, can be deployed on-site in …


Daily Stream Samples Reveal Highly Complex Pesticide Occurrence And Potential Toxicity To Aquatic Life, Julia E. Norman, Barbara J. Mahler, Lisa H. Nowell, Peter C. Van Metre, Mark W. Sandstrom, Mark A. Corbin, Yaorong Qian, James F. Pankow, Wentai Luo, Nicholas B. Fitzgerald, Multiple Additional Authors Jan 2020

Daily Stream Samples Reveal Highly Complex Pesticide Occurrence And Potential Toxicity To Aquatic Life, Julia E. Norman, Barbara J. Mahler, Lisa H. Nowell, Peter C. Van Metre, Mark W. Sandstrom, Mark A. Corbin, Yaorong Qian, James F. Pankow, Wentai Luo, Nicholas B. Fitzgerald, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

Transient, acutely toxic concentrations of pesticides in streams can go undetected by fixed-interval sampling programs. Here we compare temporal patterns in occurrence of current-use pesticides in daily composite samples to those in weekly composite and weekly discrete samples of surface water from 14 small stream sites. Samples were collected over 10–14 weeks at 7 stream sites in each of the Midwestern and Southeastern United States. Samples were analyzed for over 200 pesticides and degradates by direct aqueous injection liquid chromatography with tandem mass spectrometry. Nearly 2 and 3 times as many unique pesticides were detected in daily samples as in …