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Full-Text Articles in Physical Sciences and Mathematics

Use Of Unoccupied Aerial Vehicle (Drones) Based Remote Sensing To Model Platform Topography And Identify Human-Made Earthen Barriers In Salt Marshes, Joshua J. Ward Mar 2024

Use Of Unoccupied Aerial Vehicle (Drones) Based Remote Sensing To Model Platform Topography And Identify Human-Made Earthen Barriers In Salt Marshes, Joshua J. Ward

Masters Theses

Elevation is a foundational driver of salt marsh morphology. Elevation governs inundation and hydrological patterns, vegetation distribution, and soil health. Anthropogenic impacts at grand scales (e.g., rising sea levels) and local scales (e.g., infrastructure) have altered the elevation of the salt marsh surface, changing the topography and morphology of these ecosystems. This study establishes and assesses means to document and analyze these impacts using Unoccupied Aerial Vehicle (UAV) based remote sensing to model platform topography. This thesis’s first and primary study presents and compares methods of producing high-resolution digital terrain models (DTMs) with UAV-based Digital Aerial Photogrammetry (DAP) and Light …


Fish Assemblage Structure In Great Lakes Coastal Wetlands Over Ten Years, Matthew S. Silverhart Jan 2024

Fish Assemblage Structure In Great Lakes Coastal Wetlands Over Ten Years, Matthew S. Silverhart

Masters Theses

Coastal wetlands in the Laurentian Great Lakes are important habitats for many fish species. The geographic scale of the watershed and the diversity of land uses in the region result in substantial environmental variation among coastal wetlands. During 2011-2020, annual surveys were conducted as part of the Great Lakes Coastal Wetland Monitoring Program (GLCWMP) to better understand the status and trends of coastal wetlands. Fish sampling consisted of fyke netting in monodominant vegetation zones. During this time, 1225 unique monodominant plant zones in coastal wetlands were sampled, resulting in 584,125 fishes captured that consisted of 113 different species. Yellow Perch …


Per- And Polyfluoroalkyl Substances (Pfas) In Treated Sewage Sludge From Michigan Wastewater Treatment Plants, Garrett Wesley Link Aug 2023

Per- And Polyfluoroalkyl Substances (Pfas) In Treated Sewage Sludge From Michigan Wastewater Treatment Plants, Garrett Wesley Link

Masters Theses

Concentrations, compositions, and variability of Per- and Polyfluoroalkyl Substances (PFAS) in sewage sludge are characterized using an extensive dataset of 350 samples from 190 wastewater treatment plants (WWTPs) across Michigan. All samples are comprised of final treated sewage sludge generated at the end of the wastewater treatment process. Concentrations of Σ24 PFAS are log normally distributed with a range of 1 to 3200 ng/g dry wt. and of average 108 ± 277 ng/g dry wt. Compounds with carboxyl and sulfonic functional groups comprised 29% and 71% of Σ24 PFAS concentrations, respectively, on average. Primary sample variability is associated …


Per- And Polyfluoroalkyl Substances (Pfas) In Treated Sewage Sludge From Michigan Wastewater Treatment Plants, Garrett Wesley Link Aug 2023

Per- And Polyfluoroalkyl Substances (Pfas) In Treated Sewage Sludge From Michigan Wastewater Treatment Plants, Garrett Wesley Link

Masters Theses

Concentrations, compositions, and variability of Per- and Polyfluoroalkyl Substances (PFAS) in sewage sludge are characterized using an extensive dataset of 350 samples from 190 wastewater treatment plants (WWTPs) across Michigan. All samples are comprised of final treated sewage sludge generated at the end of the wastewater treatment process. Concentrations of Σ24 PFAS are log normally distributed with a range of 1 to 3200 ng/g dry wt. and of average 108 ± 277 ng/g dry wt. Compounds with carboxyl and sulfonic functional groups comprised 29% and 71% of Σ24 PFAS concentrations, respectively, on average. Primary sample variability is associated with …


Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek Apr 2023

Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek

Masters Theses

Tidal marshes serve as important “blue carbon” ecosystems that accrete large amounts of carbon with limited area. While much attention has been paid to the spatial variability of sedimentation within salt marshes, less work has been done to characterize spatial variability in marsh carbon density. Driven by tidal inundation, surface topography, and sediment supply, soil properties in marshes vary spatially with several parameters, including marsh platform elevation and proximity to the marsh edge and tidal creek network. We used lidar to extract these morphometric parameters from tidal marshes to map soil organic carbon (SOC) at the meter scale. Fixed volume …


Differential Toxicity Of Pm2.5 Components And Modified Health Effects Modeling: A Case Study In Nepal, Jeremy Brownholtz Apr 2023

Differential Toxicity Of Pm2.5 Components And Modified Health Effects Modeling: A Case Study In Nepal, Jeremy Brownholtz

Masters Theses

During the latter part of the 20th century, a transition away from coal as a major energy source in developed countries was accompanied by a notable decrease in air pollution-related deaths in those countries. Currently the same phenomenon is being observed in developing nations like China and India. However, many areas that do still rely on coal for their energy production or industrial needs also reflect a gap in research on the effects of those specific processes on local populations. Located in Nepal at the foot of the Himalayan Plateau, Kathmandu represents one such location. The local economy of …


Microplastic Accumulation In Terrestrial Gastropods And Soils, Gregory B. Bonilla Dec 2022

Microplastic Accumulation In Terrestrial Gastropods And Soils, Gregory B. Bonilla

Masters Theses

Microplastics (MPs) have become an emerging threat to ecosystems across the world. Transport, impacts, and fates are grossly understudied, especially in terrestrial environments. Current research on MP bioaccumulation has focused mainly on aquatic organisms with little study of terrestrial organisms, including snails where data are nearly nonexistent. To address this, we collected and examined land snails and their surrounding soil for MP content in shell and tissue. From September 11, 2020, to October 25, 2021, cover boards were placed (n=30) along relatively undisturbed sites in hardwood, forested areas, and tall grasses in a Wildlife Management Area (WMA) in Oak Ridge …


Assessment Of Soil Health Under Native Warm-Season Grasses And Different Grazing Management, Kara Leigh Grosso May 2022

Assessment Of Soil Health Under Native Warm-Season Grasses And Different Grazing Management, Kara Leigh Grosso

Masters Theses

This research uses analysis of soil quality indicators (SQIs) to compare vegetation species and grazing management over the 2021 grazing season. The soil health effect of the native warm-season grasses (NWSG) big bluestem (BB) (Andropogon gerardii) mixed with indian grass (IG) (Sorghastrum nutans) (BBIG), and switchgrass (SG) (Panicum virgatum), inter-seeded with a 12 species biodiversity mix was investigated in a 5 pressure grazing system (no graze (NG), no rest (NR), early, middle, and late rest (ER, MR, LR)). Additionally, there is a need for inexpensive tools for land owners to assess soil quality, and a validation study …


Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly Dec 2021

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …


Algorithm Performance On The Estimation Of Cdom And Doc In The North Slopes Of Alaska, Monica Weisenbach Oct 2021

Algorithm Performance On The Estimation Of Cdom And Doc In The North Slopes Of Alaska, Monica Weisenbach

Masters Theses

Use of satellite imagery makes environmental monitoring easy and convenient with little of the logistics involved in planning sampling campaigns. Colored dissolved organic matter (CDOM) is an important component to track as a proxy for the large pool of dissolved organic carbon (DOC). In a world contending with the looming issue of global climate change, the ability to investigate the carbon cycle of inland to coastal environments allows for examination of the magnitude of carbon flowing through the system and potential changes over years. The Arctic region is a critical area for climate change impacts but is a difficult landscape …


Dissolved Organic Carbon And The Potential Role To Stream Acidity In The Great Smoky Mountains National Park, Jason R. Brown Aug 2021

Dissolved Organic Carbon And The Potential Role To Stream Acidity In The Great Smoky Mountains National Park, Jason R. Brown

Masters Theses

A substantial societal shift towards environmental awareness has focused research efforts on the impacts of pollution on natural landscapes. Improvements to pollutant regulations and technology have resulted in sizeable reductions of atmospheric deposition of anthropogenic acids, especially nitrates and sulfates, which has altered the role of these ions in the environment. As such, understandings of environmental chemistry dynamics have required regular updating.

Through the National Park Service Vital Signs monitoring program, increases in precipitation pH observed in Great Smoky Mountains National Park (GRSM) has been attributed to the reduction of inorganic acid concentrations. Unfortunately, these improvements have not been uniformly …


Investigating The Ecology And Behavior Of The Indiana Bat And Tri-Colored Bat During Fall Swarming And Spring Staging, Mallory E. Tate Dec 2020

Investigating The Ecology And Behavior Of The Indiana Bat And Tri-Colored Bat During Fall Swarming And Spring Staging, Mallory E. Tate

Masters Theses

White-nose syndrome has devastated bat populations across North America since 2005. Due to declines in Indiana bat (Myotis sodalis) and tri-colored bat (Perimyotis subflavus) populations across the eastern United States, management prescriptions need to consider all seasons of these species annual cycles. However, data is severely lacking on the two seasons surrounding winter hibernation. These include fall swarming, a time period when bats are mating and preparing for hibernation, and spring staging, when bats are emerging from hibernation and preparing for spring migration. Both periods are critical for successful reproduction and survival following white-nose syndrome infection. …


Analysis Of Interdunal Wetlands And Ecosystem Dynamics Using Uas And Obia In Ludington State Park, Michigan, Claire Gilbert Aug 2020

Analysis Of Interdunal Wetlands And Ecosystem Dynamics Using Uas And Obia In Ludington State Park, Michigan, Claire Gilbert

Masters Theses

The Great Lakes sand dunes are the world's largest freshwater dune complex. There is a functional relationship between coastal wetlands and freshwater sand dune, referred to as interdunal wetlands. Interdunal wetland systems are highly dynamic and change dramatically seasonally and annually. Using geographic information systems (GIS) and unoccupied aerial systems (UAS), this thesis project is focused on understanding the spatial distribution of sparse and dense vegetation, and abiotic influence such as distance to coast, slope, and aspect influence interdunal wetland stability within a Great Lakes shoreline dune system. Object-based image analysis (OBIA) classification results extracted meaningful vegetation densities of growth …


High-Resolution Timeseries Analysis Of Dynamic Geochemistry: A 27-Well Survey Of Contaminated Groundwater Downstream Of The Former S-3 Ponds, Oak Ridge, Tennessee, Emma Dixon Aug 2020

High-Resolution Timeseries Analysis Of Dynamic Geochemistry: A 27-Well Survey Of Contaminated Groundwater Downstream Of The Former S-3 Ponds, Oak Ridge, Tennessee, Emma Dixon

Masters Theses

Spatiotemporal variability of geochemistry of contaminated groundwater has large implications on overall water quality and ability to respond to remedial applications. Gaining knowledge of how geochemistry changes over time in an area can help establish response trends to changing external conditions like weather and level of contamination. In this study, a spatiotemporal survey was performed on 27 wells at the Y-12 Complex in Oak Ridge, Tennessee. This was completed to measure diurnal fluxes in geochemistry from seasonal changes and extreme weather conditions in three areas of historically different contamination levels from a single point contamination source. Measurements were gathered over …


Using Historical Maps For Contaminated Site Identification And Prediction, And Environmental Justice Implications: A Case Study In Grand Rapids, Michigan, Dana Heusinkveld Jun 2020

Using Historical Maps For Contaminated Site Identification And Prediction, And Environmental Justice Implications: A Case Study In Grand Rapids, Michigan, Dana Heusinkveld

Masters Theses

As the production of synthetic chemicals has grown in the past centuries to increase production, lower costs, and generally make our lives more convenient, detecting and understanding the environmental impacts of these compounds has lagged significantly behind their mass production and wide-spread use. To combat this trend, sources of these contaminants, especially those that have been removed from the landscape, need to be quickly identified to make mitigation and remediation efforts more effective. In this study, historical Sanborn maps are used to extract and digitize historical site/land use in Grand Rapids during the early 1900s through the practical application of …


Assessing Mammal And Bird Biodiversity And Habitat Occupancy Of Tiger Prey In The Hukaung Valley Of Northern Myanmar, Hla Naing Jul 2015

Assessing Mammal And Bird Biodiversity And Habitat Occupancy Of Tiger Prey In The Hukaung Valley Of Northern Myanmar, Hla Naing

Masters Theses

I used results from camera traps set for tigers (Panthera tigris) during 2001-2011 in the Hukaung Valley Wildlife Sanctuary of northern Myanmar to assess overall biodiversity of large mammal and bird species, and to identify differences in photo rates inside and outside of the most protected core area of the Sanctuary. A total of 403 camera stations were deployed during October-July in the dry seasons of 2001-2011, 260 inside the Core area and 143 Outside. From 10,750 trap-nights I obtained 2,077 independent photos of wildlife species and 699 of domestic animals and humans, including 35 species of wild …


Characterizing Groundwater Ch4 And 222rn In Relation To Hydraulic Fracturing And Other Environmental Processes In Letcher County, Ky, St. Thomas Majeau Ledoux May 2015

Characterizing Groundwater Ch4 And 222rn In Relation To Hydraulic Fracturing And Other Environmental Processes In Letcher County, Ky, St. Thomas Majeau Ledoux

Masters Theses

Hydraulic fracturing of shale deposits has greatly increased the productivity of the natural gas industry by allowing it to exploit previously inaccessible reservoirs. However, previous research has demonstrated that this practice can contaminate shallow aquifers with CH4 [methane] from deeper formations. This study compares concentrations and isotope compositions of CH4 sampled from domestic groundwater wells in Letcher County, Kentucky in order to characterize its occurrence and origins in relation to neighboring hydraulically fractured natural gas wells. Additionally, this study tests the reliability of 222Rn [radon] as an alternative tracer to CH4 in identifying processes of gas …


A Remote Sensing Based Early Warning System For Algal Blooms In Kuwait Bay And Coastal Waters, Cameron Manche Dec 2014

A Remote Sensing Based Early Warning System For Algal Blooms In Kuwait Bay And Coastal Waters, Cameron Manche

Masters Theses

The Kuwait Bay and its coastal waters are being threatened by a perpetual hazard, the proliferation of harmful algal blooms (HABS). The frequency of HAB occurrences is a growing problem that is only reported subsequent to the onset of a HAB event. Little effort has been invested in investigating the spatial and temporal distribution of these events in Kuwait Bay and even less is known about their controlling factors. All previous studies within the Kuwait Bay have focused either on measuring nutrient availability and the biodiversity of algal species.

The overall study objective is four-fold: (1) to monitor the spatial …


Estimating Streambank Erosion Using Gps-Based Watershed-Scale Video Mapping And Usepa Bancs For The Development Of Sediment Tmdls, Kelsey Jo Hensley Dec 2014

Estimating Streambank Erosion Using Gps-Based Watershed-Scale Video Mapping And Usepa Bancs For The Development Of Sediment Tmdls, Kelsey Jo Hensley

Masters Theses

According to the United States Environmental Protection Agency (USEPA), sediment is one of the most common water pollutants in the nation’s rivers. Consequently, the identification of streambank locations with high erosion potential is important in reducing sediment input via management and monitoring practices. Furthermore, the estimation of erosion rates and sediment loads can assist in the development of Total Maximum Daily Loads (TMDLs). The objective of this study was to integrate two USEPA-recommended approaches with the Streambank Video Mapping System (SVMS) in order to predict site-specific Total Daily Sediment Loads (TDSLs) and calculate sediment TMDLs for streambank erosion over several …


Measuring Carbon Dioxide (Co2) Flux Of Agricultural Practices In Sub-Saharan Africa, Debra Blumberg O'Dell Aug 2014

Measuring Carbon Dioxide (Co2) Flux Of Agricultural Practices In Sub-Saharan Africa, Debra Blumberg O'Dell

Masters Theses

Agriculture has an important role in addressing two of the world’s most pressing problems: meeting global food demand and mitigating climate change. If agriculture is not practiced sustainably it will fail to meet future food demand and likely intensify the pace of global climate change. There are some agricultural practices, such as Conservation Agriculture, that can produce food sustainably and have the potential to mitigate climate change. However it is not clear which agricultural practices contribute to climate mitigation and by how much. By measuring the carbon dioxide (CO2) emissions of specific agricultural practices, the ability of practices to sequester …


Freshwater Mussels (Bivalvia: Margaritiferidae And Unionidae) Of The Buffalo River Drainage, Tennessee, Matthew Philip Reed May 2014

Freshwater Mussels (Bivalvia: Margaritiferidae And Unionidae) Of The Buffalo River Drainage, Tennessee, Matthew Philip Reed

Masters Theses

The Buffalo River in Tennessee once hosted a rich population of freshwater mussels. During the 1980s, monitoring efforts demonstrated evidence of drastic declines and extirpation of entire assemblages. Increases in municipal development in the headwater tributaries and agriculture in the main stem of the Buffalo River are suspected causes for mussel community declines throughout the river. In 2011, collection data documented evidence of recovery in the lower Buffalo River. The aims of this project were: 1) to update the status, distribution, and species composition of mussels in the Buffalo River and its major tributaries through qualitative sampling, and 2) to …


Linking Stream Sediment Metrics And Aquatic Macroinvertebrate Status In East Tennessee Streams, Grant Thomas Lynch Aug 2013

Linking Stream Sediment Metrics And Aquatic Macroinvertebrate Status In East Tennessee Streams, Grant Thomas Lynch

Masters Theses

Excess sediment is one of the leading causes of impairment of the rivers and streams of Tennessee and in the United States. Sediment acts as a pollutant by degrading the quality of habitat for fish and other aquatic life. The Tennessee Department of Environment and Conservation (TDEC) currently assesses the quality of streams in Tennessee by conducting benthic macroinvertebrate surveys. These surveys use seven biometrics to calculate Tennessee Macroinvertebrate Index (TMI) scores. This method is well tested and reliable, but it has not been shown to directly link changes in stream sediment characteristics to macroinvertebrate status. Finding a stream sediment …


Kingston Fossil Plant Ash Spill & Corbicula Fluminea: Assessing The Effectiveness Of An Invasive Bivalve As A Biomonitor Of Coal Ash Pollution, Hannah Ruth Johnson Aug 2013

Kingston Fossil Plant Ash Spill & Corbicula Fluminea: Assessing The Effectiveness Of An Invasive Bivalve As A Biomonitor Of Coal Ash Pollution, Hannah Ruth Johnson

Masters Theses

The goal of this study was to assess the effectiveness of using the invasive Asian clam, Corbicula fluminea, as a biomonitor for trace element bioavailability in the river system affected by the Kingston Fossil Plant coal ash spill of December 2008. I collected Corbicula from five different sites (n=20 per site) and analyzed both the soft body tissues and shells via inductively coupled plasma-optical emission spectroscopy (ICP-OES). I then compared the concentrations of a suite of elements in Corbicula fluminea among sampling sites and examined the correlation between soft tissue and shell concentrations. The multiple analysis of variance (MANOVA) …


Adsorption Of Antimony By Birnessite And The Impact Of Antimony On The Electrostatic Surface Properties Of Variable-Charge Soil Minerals, Kalyn Alaine Vergeer May 2013

Adsorption Of Antimony By Birnessite And The Impact Of Antimony On The Electrostatic Surface Properties Of Variable-Charge Soil Minerals, Kalyn Alaine Vergeer

Masters Theses

Antimony (Sb) is a toxin that can be found in high concentrations in the soil due to anthropogenic sources. Antimony exists in soil as Sb(V) in the monovalent antimonate hydroxyanion. The adsorption mechanisms of Sb(V) are not well-characterized. The objective of this study was to further elucidate Sb(V) adsorption mechanisms by examining the impact of adsorption on surface charging characteristics of gibbsite, goethite, birnessite, and kaolinite. Also examined was Sb(V), SO4 [sulfate], and PO4 [phosphate] adsorption by birnessite. Electrophoretic mobility and potentiometric titrations were employed to examine the ζ-potential [zeta-potential] and net proton surface charge density as a …


Mussel Survivorship, Growth Rate And Shell Decay Rate In The New River Basin Of Tennessee: An Experimental Approach Using Corbicula Fluminea, Grant Andrew Mincy Aug 2012

Mussel Survivorship, Growth Rate And Shell Decay Rate In The New River Basin Of Tennessee: An Experimental Approach Using Corbicula Fluminea, Grant Andrew Mincy

Masters Theses

The New River Basin (NRB) of Tennessee is home to a number of rare endemic aquatic communities. One such community of particular importance to the area, experiencing a precipitous population decline due to the fouling and pollution of their freshwater systems, is that of freshwater mussels (Bogan 2006). This study in the NRB involves measuring the mortality rates of live Asian clams (Corbicula fluminea) assemblages and the shell decay rates of their death assemblages. This study also examines the decay rates of the native Villosa iris to gather information on molluscan health and the ability of their shells …


Capture-Recapture Of White-Tailed Deer Using Dna Sampling From Fecal Pellet-Groups, Matthew James Goode Dec 2011

Capture-Recapture Of White-Tailed Deer Using Dna Sampling From Fecal Pellet-Groups, Matthew James Goode

Masters Theses

Reliable density estimates of game and keystone species such as white-tailed deer (Odocoileus virginianus) are desirable to set proper management strategies and for evaluating those strategies over time. However, traditional methods for estimating white-tailed deer density have been inhibited by behavior, densely forested areas that can hamper observation (detection), and invalid techniques of estimating effective trapping area. We wanted to evaluate a noninvasive method of mark-recapture estimation using DNA extracted from fecal pellets as the individual marker and for gender determination, coupled with a spatial detection function to estimate density (Spatially Explicit Capture-Recapture, SECR). We collected pellet groups …


Evaluating Substrate Metrics For Monitoring Sediment Impairment Of East Tennessee Streams., James Hunter Terrell Aug 2011

Evaluating Substrate Metrics For Monitoring Sediment Impairment Of East Tennessee Streams., James Hunter Terrell

Masters Theses

Section 303(d) of the Clean Water Act (CWA) requires states to assess and list all streams that do not meet water quality criteria for their designated use classes. In Tennessee, the Tennessee Department of Environment and Conservation (TDEC) uses macroinvertebrate surveys to assess the condition of streams designated for “fish and aquatic life” and the progress of targeted waterbodies toward meeting established standards for sediment. As of yet, no substrate metric has been established to monitor water quality or to document progress toward water quality improvement with respect to fish and aquatic life in Tennessee. A substrate metric that could …


The Effects Of Land-Use Change On The Hydrological Properties Of Andisols In The Ecuadorian Paramo, James Joseph Hartsig May 2011

The Effects Of Land-Use Change On The Hydrological Properties Of Andisols In The Ecuadorian Paramo, James Joseph Hartsig

Masters Theses

The Ecuadorian páramo is characterized by unique soil properties that allow the ground to hold large amounts of water. These páramo grasslands support Andean cities and communities as a source of water for municipal, industrial, and agricultural use. Although recent research has suggested that changes in land use can decrease the amount of water and affect the water-holding capabilities of the soil, the hydrologic effects of different land uses, including burning for livestock grazing and pine planting for carbon credits, are currently under debate.

This research tested hypotheses about moisture-related properties of páramo soils under different land uses at two …


Phosphorus Distribution In Channel-Bed Sediments In Beaver Creek, Knox County, Tennessee, Angela Nicole Danovi May 2011

Phosphorus Distribution In Channel-Bed Sediments In Beaver Creek, Knox County, Tennessee, Angela Nicole Danovi

Masters Theses

Beaver Creek, located in North Knox County, Tennessee, is on the Tennessee 303(d) list as an impaired stream that fails to meet its designated uses. Phosphorus (P) is one of the major pollutants of the stream. High P levels within surface water can lead to water quality problems including low dissolved oxygen, overgrowth of algae, and eutrophication. Two sources, pasture grazing areas and major municipal point sources, have been identified as important contributors of P to Beaver Creek. The objective of this study was to analyze the total P and Mehlich III extractable P concentrations of sediments in Beaver Creek …


The Effects Of Changes In Water Content On Uranium(Vi) Leaching In Sediment Mixtures Containing Gravel, Andrew Weber Moore Aug 2010

The Effects Of Changes In Water Content On Uranium(Vi) Leaching In Sediment Mixtures Containing Gravel, Andrew Weber Moore

Masters Theses

This study is aimed at understanding the physical and chemical effects that changes in water content have on uranium leaching in sediment containing gravel. It was hypothesized that leaching will be more efficient under unsaturated conditions because flow will be restricted to the smallest pores and will have the most contact with the uranium contaminated sediment. Under saturated conditions, a large portion of the flow will bypass the < 2 mm material, and in turn not come into contact with uranium contaminated material. Batch adsorption and desorption experiments were performed on < 2 mm ERDF sediment to determine the linearity and reversibility of sorption processes and to aid in the interpretation of the leaching experiments. Results of the desorption experiments on aged, contaminated sediments show that the mass percent of sorbed U(VI) released to solution decreased as the sorbed concentration of U(VI) decreased. The opposite trend was observed on freshly contaminated sediments. This indicated that aging increased U(VI) affinity for the solid phase and was attributed to either the crystallization of calcite, which incorporated a portion of the sorbed U(VI) as it crystallized, or the presence of voids in basaltic lithic fragments accessed by diffusion. Column leaching experiments were performed at two water contents on artificially contaminated sediment collected from the Department of Energy’s (DOE) Hanford Site, Washington state. The sediment contained 81.3% gravel (> 2 mm) by mass. Non-reactive tracers were well fit with the convection-dispersion equation (CDE) at both high and low water contents indicating physical equilibrium. The column experimental data were fitted to an …