Engineering Commons^™

Quantitative Sustainable Design Of Urban Tree Soil Cells For Stormwater Management, Jamaya Wilson

Theses and Dissertations--Civil Engineering

Urban trees are critical assets to cities around the world. They act as a green infrastructure system to provide various environmental, economic and social benefits to their surrounding environments. However, the quality of life of urban trees is severely threatened by uncontrolled urbanization and climate change. The compaction of urban soils to meet the structural stability requirements for buildings and pavements directly restricts tree growth. Soil cells are green infrastructure placed in tree wells to transfer active and static loads to pavements. This allows for reduced soil compaction and increased tree root expansion. However, because the technology is still in …

Nanopesticide Influence On Nitrogen Cycling In Soils, Jacob Richardson

Theses and Dissertations--Biosystems and Agricultural Engineering

Nanotechnology has several applications in the agricultural industry, as the small size of nanoparticles and high reactivity enables targeted delivery of pesticides and fertilizers to the intended crop. Copper-based nanopesticides such as Kocide, are proposed as a more efficient method for targeted pest control. Despite the potential benefits of nanopesticides, little is known regarding the transport and implications of nanopesticides under long-term inundation conditions often found in downstream wetlands. Specifically, the impact of nanopesticides on microbial nitrogen processes in wetland environments remains unknown. Therefore, this thesis explores the impact of nanopesticides, specifically Kocide, on microbial nitrogen cycles in agricultural and …

Sewer Vapor Intrusion Pathway: Simulation Of Indoor Piping Systems And Operation Of Aroma-Voc Gas Analyzer, Hong Cheng Tay

Theses and Dissertations--Civil Engineering

Vapor Intrusion (VI) is a transport phenomenon that occurs when contaminants migrate from sub-surface sources into indoor spaces. Sewer tunnels, plumbing connections, and piping infrastructures can be important contributors to an increased potential of VI in a site, which results in indoor concentrations of volatile organic compounds (VOC). In the present work, the topic of sewer VI pathways were investigated through a prototype made from various types of indoor plumbing pipe fittings. This prototype simulates indoor piping systems and determine whether air and VOC were escaping through the pipe fittings. Moreover, this study is the first effort to use a …

Investigation Of Pfas Exposure Risks In Kentucky Using Mapping Tools, Sweta Ojha

Theses and Dissertations--Civil Engineering

Per- and polyfluoroalkyl substances (PFAS), a group of environmentally-persistent compounds, are environmentally ubiquitous and challenging to remediate. Several studies show that PFAS are detected in drinking water systems when sampling is conducted, making human exposure via drinking water an important health consideration. This research: 1) develops a mapping tool for prioritizing sampling locations; 2) establishes a method for making GIS data and meta(data) in the mapping tool accessible; 3) fosters decision making by integrating knowledge brokering and the alignment interest and influence matrix (AIIM). The tool developed is this research is a geospatial and statistical PFAS hot-spot screening model that …

Using Stream Restoration To Mitigate Stormwater Runoff In An Urban Watershed: A Case Study, Jonathan M. Brantley

Theses and Dissertations--Biosystems and Agricultural Engineering

The goal of this case study was to evaluate the effectiveness a 275 m regenerative stream restoration design to mitigate stormwater runoff in a highly urbanized watershed. The restoration resulted in a wide, wetland-like floodplain, comprised of a rock base that was overtopped with a filtration media (approximately 30% woodchips and 70% topsoil). The creation of the floodplain-wetland complex in tandem with filtration media lead to increased storage capacity and an increase in hyporheic exchange within the system. Significant reductions were found for the storm hydrograph parameters volume, peak discharge, and time to peak. Reductions in baseflows were also noted …

Classifying And Mapping Aquatic Vegetation In Heterogeneous Stream Ecosystems Using Visible And Multispectral Uav Imagery, Rozalia Agioutanti

Theses and Dissertations--Biosystems and Agricultural Engineering

The need for assessment and management of aquatic vegetation in stream ecosystems is recognized given the importance in impacting water quality, hydrodynamics, and aquatic biota. However, existing approaches to monitor are laborious and its currently not feasible to track spatial and temporal differences at broad scales. The objective of this study was therefore to map and classify aquatic vegetation of a shallow stream with heterogenous mixtures of emergent and submerged aquatic vegetation. Data was collected in the Camden Creek watershed within the Inner Bluegrass Region of central Kentucky. The use of unmanned aerial vehicles (UAVs) was employed and both visible …

Sediment Nitrogen Dynamics In Backwater Wetland Confluences Of A Regulated River, Gina Degraves

Theses and Dissertations--Biosystems and Agricultural Engineering

As harmful algal blooms in regulated river systems have increased in the past decade, the importance of understanding sediment nutrients has also increased. Research linking nutrient processes and fine sediment dynamics to harmful algal blooms in confluence wetlands along regulated rivers has recently become apparent. However, the relationship between sediment nutrient dynamics in confluence wetlands has been understudied. Utilization of sediment fingerprinting, high-frequency water quality monitoring, and tracer unmixing mass-balance modeling, was able to suggest sediment N mineralization in Appalachia confluence riparian wetland was not a dominate source of nitrate downstream. Further measures of supplementary tracers and additional sediment sources …

Assessing Machine Learning Utility In Predicting Hydrologic And Nitrate Dynamics In Karst Agroecosystems, Timothy Mcgill

Theses and Dissertations--Biosystems and Agricultural Engineering

Seasonal hypoxia in the Gulf of Mexico and harmful algal blooms experienced in many inland freshwater bodies is partially driven due to excessive nitrogen loading seen from agricultural watersheds. Within the Mississippi/Atchafalaya River Basin, many areas are underlain with karst features, and efforts to reduce nitrogen contributions from these areas have had varying success, due to lacking a complete understanding of nutrient dynamics in karst agricultural systems. To improve the understanding of nitrogen cycling in these systems, 35 months of high resolution in situ water quality and atmospheric data were collected and fed into a two-hidden layer extreme learning machine …

Development Of Novel Polymeric Materials For Their Application In Monitoring And Remediation Of Environmental Pollutants, Rishabh Shah

Theses and Dissertations--Chemical and Materials Engineering

Remediation of environmental pollutants from water is one of the major challenges in the 21st century. Utilizing novel polymeric materials to accomplish this challenge has garnered a lot of interest in recent times. Flexibility in synthesizing as well as functionalizing makes them attractive for their application in pollutant remediation. This work is based on development and characterization of novel crosslinked polymeric as well as linear polymeric materials from biphenyl-based monomers, biphenyl based crosslinker and a temperature responsive monomer (Nisopropylacrylamide (NIPAAm)) for their application in remediation of toxic pollutants such as polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs) and iron oxide nanoparticle …

Life Cycle Assessment Of Polylactic Acid Biopolymer Industrial Waste Management Techniques In Belize, Dennis J. Newby

Theses and Dissertations--Civil Engineering

In January 2020, the Government of Belize enacted an Implementation Strategy and Action Plan to phase-out single-use plastics and to transition to products like bioplastics. This work investigated the environmental effects of using alternative waste management techniques to manage polylactic acid biopolymer (PLA) waste by using life cycle assessment (LCA). The following treatment options were compared: landfill, landfill expansion, cogeneration, and anaerobic digestion. The landfill and landfill expansion processes both had a global warming potential of 0.01 kg of CO₂ eq. per kg of PLA waste managed compared to the cogeneration and anaerobic digestion processes -0.03 and -0.06 kg …

Evaluation Of Liquid Ice Melting Additives For Winter Maintenance Applications, Erin Lammers-Staats

Theses and Dissertations--Civil Engineering

Winter weather can often pose difficulties for transportation agencies as they work to clear roads of snow and ice quickly so that motorists can travel safely and efficiently. Kentucky has made efforts to maximize efficiency within its winter maintenance program by focusing on optimized equipment usage and personnel time management. This study’s objective was to evaluate novel anti-icers and calculate how their performance compared to the current performance of brine and calcium chloride mixture. New brine additives claim to offer better results, but there is very little guidance about how to systematically evaluate new anti-icers. The author developed a testing …

Quantifying The Source And Pathway Of Dissolved Reactive Phosphate In Karst Drainage Of The Inner-Bluegrass, Cory Radcliff

Theses and Dissertations--Biosystems and Agricultural Engineering

In the Midwestern U.S. seasonal hypoxia experienced in the Gulf of Mexico and harmful algal blooms in inland freshwater ponds, lakes, and rivers are partly fueled by dissolved orthophosphate loadings from disturbed landscapes. Efforts to reduce dissolved reactive phosphate (DRP) loadings have had varying levels of success and have led to insufficient water quality improvements. Inefficiencies in conservation strategies can stem from poor understanding of phosphate source and flow pathway dynamics. This study focused on monitoring sources and flow pathways of dissolved reactive P in a karst agroecosystem with phosphatic limestone. We collected event water samples at the Camden Creek …

Impact Of Preferential Flow, Source Water Connectivity, And Agricultural Management Practices On Sediment And Particulate Phosphorus Dynamics In Midwestern Tile-Drained Landscapes, Saeid Nazari

Theses and Dissertations--Biosystems and Agricultural Engineering

Tile drainage is recognized as a significant transporter of sediment and particulate phosphorus (PP) in the Midwestern U.S., leading to proliferation of Harmful Algal Blooms (HABs). Numerous studies have focused on Dissolved Reactive Phosphorus (DRP) and Nitrogen (N) flux dynamics in tile-drained landscapes; however, the impact of preferential flow and agricultural management practices on fate and transport of sediment and PP has remained poorly understood. The overarching objective of this study was to improve understanding of sediment P delivery in tile-drained landscapes. This dissertation focuses on four studies. In the first study, forms and flow pathway dynamics of total phosphorus …

Evaluating The Biotic Condition Of Restored Streams In Kentucky’S Inner Bluegrass Region, Charles Cole Crankshaw

Theses and Dissertations--Biosystems and Agricultural Engineering

Numerous stream restoration projects have been implemented in Kentucky’s Inner Bluegrass region to offset anthropogenic impacts. These projects range from full channel realignments to volunteer-led riparian installations. To assess the ability of said projects to restore stream habitat and biota, full restoration (n=12) and riparian (n=6) sites were compared to reference (n=6) and disturbed (n=12) sites using RBP and SVAP protocols, macroinvertebrate samples, and geomorphology. General trends for SVAP, RBP, and BI scores, starting with highest habitat or biotic quality, were reference sites, full and riparian restoration sites, then disturbed sites. The number of EPT taxa, another indicator of biological …

Fluvial Sediment Organic Matter Degradation Identified With Elemental And Isotopic Fate During Laboratory Incubation, Brenden Riddle

Theses and Dissertations--Civil Engineering

Fluvial sediment is well recognized as a critical factor in both carbon and nutrient budgets within stream systems. However, we find very few studies of reactivity and isotope enrichment for stream water from agricultural and urban streams and the class of substrate known as fluvial sediment organic matter. This study investigated the hypothesis that fluvial sediment is subject to degradation even though many previous studies have considered this class of substrate generally inert. Therefore we qualify that elemental and isotopic signatures of fluvial sediment organic matter should be considered potentially non-conservative when used in tracer studies. Methods applied to this …

Probabilistic Approach To Water, Sediment, And Nutrient Connectivity For Advancing Watershed Modelling, David Tyler Mahoney

Theses and Dissertations--Civil Engineering

The goal of this dissertation is to represent the spatial and temporal domains of water, sediment, and nutrient flux and pathways within fluvial and watershed settings. To complete this goal, we integrate connectivity theory into watershed model structures to simulate water, sediment, and nutrient movement at the fundamental unit they occur. Fluvial-based sediment and nutrient flux is an important driver of global sediment and nutrient budgets, and the quantification of which serves as an ongoing challenge to limnologists, engineers, and watershed managers. Watershed models have been richly developed over the past century, but are currently restrained by problems related to …

A Modeling Approach To Understanding Glyphosate Transport In The Belize River Watershed, Barbara Anmei Astmann

Theses and Dissertations--Civil Engineering

Glyphosate is the most widely used herbicide worldwide and is often transported from application areas to surface water when solubilized in runoff or sorbed to eroded sediment. There is evidence that suggests both glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) may pose a risk to human health, as well as cause adverse effects in the environment. However, consistent monitoring data is still limited, especially in developing countries. Belize is a developing nation with agriculture being a major sector of its economy and is heavily reliant on glyphosate. The widespread use of glyphosate in Belize may be resulting in glyphosate …

Investigation Into The Presence, Persistence, And Fate Of S. Aureus, And Its Mobile Genetic Elements, In Wastewater And The Surrounding Environment, Atena Amirsoleimani

Theses and Dissertations--Civil Engineering

Currently, the world is engaged in a battle against very small parts of our environment that develop and share genes for resistance to multiple environmental conditions. Pathogenic infections caused by antibiotic-resistant bacteria have been impacting animal and human health and life. Increasing incidences of methicillin- resistant Staphylococcus aureus (MRSA) infections transmitted through the environment are rising faster than the discovery of new antibiotics. Multi-drug resistant S. aureus infections in healthy individuals without prior hospitalization have been increasing all around the world.

Many people carry S. aureus in their nose and on their skin, common niches for the bacteria to co-grow …

Soil Bulk Density Effects On Runoff Estimation, Colton Pugh

Theses and Dissertations--Biosystems and Agricultural Engineering

Urbanization has long been a major factor in the hydrology of surrounding areas. Engineers are commonly tasked with mitigating the extra runoff that urbanization brings with it. The NRCS Curve Number (CN) method is a commonly-used approach to predicting the amount of runoff that will be experienced from a given area. However, this method is known to be highly simplified in model of the processes involved. This study focused on determining the relationships between soil bulk density, simulated rainfall events, hydrologic soil group (HSG) and runoff estimation (specifically via the NRCS CN method). It was determined that soil bulk density …

Variance Decomposition Of Forecasted Water Budget And Sediment Processes Under Changing Climate In Fluvial And Fluviokarst Systems, Nabil Al Aamery

Theses and Dissertations--Civil Engineering

Variance decomposition is the partitioning of different factors affecting the variance structure of a response variable. The present research focuses on future streamflow and sediment transport processes projections as the response variables. The authors propose using numerous climate factors and hydrological modeling factors that can cause any response variable to vary from historic to future conditions in any given watershed system. The climate modeling factors include global climate model, downscaling method, emission scenario, project phase, bias correction. The hydrological modeling factor includes hydrological model parametrization, and meteorological variable inclusion in the analysis. This research uses a wide spectrum of data, …

Quantifying Nitrogen Fate In Karst Agroecosystem Streams Of Central Kentucky: Development And Application Of Numerical Modeling And Insight From High-Resolution Sensors, Nolan Lewis Bunnell

Theses and Dissertations--Biosystems and Agricultural Engineering

In-stream fate of nutrients in karst agroecosystems remains poorly understood, despite the known impact of karst on water resources at local to global scales. In the Inner-Bluegrass region of central Kentucky, heterogeneity of karst maturity, flow pathways, and nutrient sources adds to the complexity of quantifying nutrient dynamics, thus requiring novel monitoring and modeling approaches. The significance of these streams is recognized given spring/surface water confluences have been identified as hotspots for biogeochemical transformations. In slow-moving streams high in dissolved inorganic nutrients (particularly dissolved inorganic nitrogen (DIN) and dissolved reactive phosphorus (DRP)), benthic and floating aquatic macrophytes are recognized to …

Synthesis, Characterization And Applications Of Reduced Graphene Oxide And Composite Membranes For Selective Separations And Removal Of Organic Contaminants, Ashish Aher

Theses and Dissertations--Chemical and Materials Engineering

Among the next generation materials being investigated for membrane development, partially reduced Graphene Oxide (rGO) has received increasing attention from the membrane community. rGO-based nanofiltration membranes have shown promising results in applications such as partial desalination, organic contaminant removal, gas-phase separations, and separations from solvent media. rGO offers a unique platform compared to common polymeric membranes since it can be used for separation applications in both aqueous and organic solvent media. An rGO-based platform could also be utilized to synthesize reactive membranes, giving rGO membranes the additional capability of reactively removing organic contaminants. This research focuses on the synthesis of …

Use Of Functionalized Bimetallic Membranes For Treatment Of Contaminated Groundwater At A Hazardous Waste Site In Kentucky, Lucy C. Pacholik

Theses and Dissertations--Civil Engineering

Providing access to clean drinking water will continue to be a challenge for civil engineers for generations to come. Since many communities around the world rely on groundwater as a source of drinking water, remediation technologies must be implemented at sites where groundwater contamination exists due to years of mismanagement of hazardous waste. Using nanosized zero-valent metals such as iron and zinc embedded within and on the surface of functionalized (PAA) membrane filters has shown to be an effective dechlorination technique for contaminated groundwater. Introducing a noble metal such as Pd or Ni increases reaction rates by acting a catalyst …

Investigation Of Atmospheric Effects On Vapor Intrusion Processes Using Modelling Approaches, Elham Shirazi

Theses and Dissertations--Civil Engineering

Most people in the United States (US) spend considerable amount of time indoors—about 90% of their time as compared to outdoors, which makes the US population vulnerable to adverse health effects of indoor air contaminants. Volatile organic compound (VOC) concentrations are well-known to be higher in indoor air than outdoor air. One source of VOC concentrations in indoor air that has gained considerable attention in public health and environmental regulatory communities is vapor intrusion. Vapor intrusion is the process by which subsurface vapors enter indoor spaces from contaminated soil and groundwater. It has been documented to cause indoor air contamination …

Pathway Connectivity In An Epigenetic Fluviokarst System: Insight From A Numerical Modelling Study In Kentucky Usa, Ethan Adams

Theses and Dissertations--Civil Engineering

Fluviokarst landscapes are dominated by both fluvial and karst features. Interpreting hydrologic pathways of fluviokarst can be confounded by the unknown connectivity of the various flow regimes. A combined discrete-continuum (CDC) hybrid numeric model for simulating the surface and subsurface hydrology and hydraulics in fluviokarst basins was formulated to investigate fluviokarst pathways. This model was applied to the Cane Run Royal Springs basin in Kentucky USA. A priori constraints on parameterization were avoided via multi-stage optimization utilizing Sobol sequencing and high performance computing. Modelling results provide evidence of hydrologic pathways dominated by fracture flow, epikarst transfer and runoff. Fractures in …

Biological Selenium Control: Selenium Reduction By Shigella Fergusonii Strain Tb42616 And Pantoea Vagans Strain Ewb32213-2 In Bioreactor Systems, Yuxia Ji

Theses and Dissertations--Civil Engineering

Se(VI) and Se(IV), as the two major species of selenium in water, are toxic to aquatic lives and may cause adverse health effects to humans at high levels. Biological reduction of Se(VI) is a two-stage process first from Se(VI) to Se(IV) and then from Se(IV) to Se(0) with potential accumulation of the more toxic Se(IV) due to the slower rate of the second stage.

Selenium reduction was first evaluated with batch cultures of Shigella fergusonii strain TB42616 (TB) and Pantoea vagans strain EWB32213-2 (EWB) isolated in our laboratory from sludge and coal slurry sediment samples, respectively. In order to facilitate …

Decomposing A Watershed’S Nitrate Signal Using Spatial Sampling And Continuous Sensor Data, Evan Clare

Theses and Dissertations--Civil Engineering

Watershed features, physiographic setting, geology, climate, and hydrologic processes combine to produce a time-variant nutrient concentration signal at the watershed outlet. Anthropogenic influences, such as increased agricultural pressures and urbanization, have increased overall nutrient loadings delivered to the fluvial network. The impact of such increased nutrient loadings on Kentucky’s drinking water remains a potential threat to the region.

By coupling spatial sampling of nitrate concentrations in surface water with contemporary nutrient and water quality sensor technology, a decomposition of the Upper South Elkhorn watershed’s nitrate signal and an estimation of source timing and loading in the watershed was completed. The …

Investigation Of The Effectiveness Of An Integrated Flooded-Bed Dust Scrubber On A Longwall Shearer Through Laboratory Testing And Cfd Simulation, Sampurna N. Arya

Theses and Dissertations--Mining Engineering

Dust generation at an underground coal mine working face continues to be a health and safety issue. Prolonged exposure to high concentrations of airborne respirable dust can cause a debilitating and often fatal respiratory disease called Black Lung. In addition, the deposition of float dust in mine return airways poses a serious safety hazard if not sufficiently diluted with inert rock dust. A localized methane explosion can transition into a self-propagating dust explosion. Since dust is a byproduct of various mining activities, such as cutting and loading, crushing, and transportation, the dust-related issues cannot be totally eliminated. However, the adverse …

Assessment Of Watershed Nutrient Loads And Effectiveness Of Best Management Practices, Saeid Nazari

Theses and Dissertations--Civil Engineering

Several methods have been developed for use in estimating the water quality loads associated with urban and agricultural landuses and practices. These include the use of sophisticated computer models, typically based on using pollutant loading and runoff functions, regression equations, load export coefficients (LECs), and event mean concentrations (EMCs). This research has examined the feasibility of using a simple EMC approach with the Kentucky Nutrient Model (KYNM). The thesis includes an extensive literature review of EMCs and a synthesis of recommended values for a range of typical urban and agricultural landuses. The thesis also includes an extensive literature review of …

Preferential Pathways For Vapor Intrusion: Site Screening And Field Sampling Of Sewers To Assess Inhalation Exposure Risks, Evan James Willett

Theses and Dissertations--Civil Engineering

Hazardous waste sites and aging wastewater infrastructure are common in the United States. There are hundreds of thousands of contaminated sites and more than a million miles of sewer pipes. Populations living close to hazardous waste sites often suffer from increased risk of adverse health effects due to exposure to contaminated environmental media. Vapor intrusion is one process by which nearby populations can be exposed to volatile organic compounds (VOCs). Aging wastewater infrastructure is important for vapor intrusion site assessments because sewer pipes can serve as preferential vapor transport pathways. Near contaminated sites, pipe deterioration allows migration of contaminants into …