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Environmental Engineering

Theses/Dissertations

2020

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Full-Text Articles in Physical Sciences and Mathematics

Characterizing Reactive Iron Mineral Coatings And Their Roles In Natural Attenuation At A Site With Historical Contamination, Han Hua Dec 2020

Characterizing Reactive Iron Mineral Coatings And Their Roles In Natural Attenuation At A Site With Historical Contamination, Han Hua

Dissertations

Reactive iron mineral coatings in redox transition zones play an important role in contaminant attenuation. These mineral coatings include poorly crystalline to crystalline iron sulfides, carbonates, and oxyhydroxides, and are a signature of the biogeochemical processes occurring. To better understand these processes, reactive iron mineral coatings are characterized in an 18-m Anaerobic Core collected from a contaminated industrial site. This study targets redox transition zones uncovered in the core. A suite of complementary analyses is applied to distinguish the surface coating mineralogy using X-ray Diffraction, X-ray fluorescence, and field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray analyzer (EDX). In …


Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques Dec 2020

Policy Changes Impact In Deforestation Of The Brazilian Amazon, Iara Silva Jaques

Master's Projects and Capstones

Since discovered and inhabited, the Brazilian Amazon has been explored and impacted negatively by human activities. The conversion of forest to pastureland and farmland, as well as mining activities, road opening, wood and ore extraction and fire are historically the main causes of environmental damages and forest loss in the region. This project overviewed the latest changes in environmental policy and practices towards environmental protection conducted by the Brazilian president Jair Bolsonaro, since he took office in 2019, and analyzed the progress of deforestation in the recent years under the new federal administration. Geographic Information System analysis were used to …


Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite Dec 2020

Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite

Theses and Dissertations

The construction industry is facing many challenges. There are growing consumer demands for sustainable building. The construction industry generates a significant portion of the waste going into landfills. The construction industry has failed to keep pace with productivity in the manufacturing industry. Through adoption of Lean management principles, the construction industry can become more sustainable while increasing productivity. The literature was evaluated for three concepts: Lean management principles interaction with sustainability, the current state of sustainability in the construction industry, and the current state of Lean management principles in the construction industry. Lean management philosophies interactions with sustainability has been …


Assessing Grassed Waterway Implementation Using Acpf And Swat Models, Kirsten Schaefer Dec 2020

Assessing Grassed Waterway Implementation Using Acpf And Swat Models, Kirsten Schaefer

MSU Graduate Theses

Agriculture is the most significant contributor of nonpoint source pollutants in US waterways, with sediment being the most prevalent cause of impairments. Sediment loss mitigation occurs through Best Management Practices (BMPs), such as grassed waterways. Federal and state agencies incentivize the implementation of BMPs through cost-share programs for farmers. The investment of public funds has increased pressure to demonstrate the effectiveness and value of individual projects, necessitating the development of strategies for prioritizing projects based on the sensitivity of sites to sediment erosion and optimal locations for implementation. This study has three primary objectives: (i) document existing locations of grassed …


Numerical And Experimental Investigation Of Aeration Self Mixing By Using Pulsating And Continuous Air Flow, Ahmed Ali Alkhafaji Dec 2020

Numerical And Experimental Investigation Of Aeration Self Mixing By Using Pulsating And Continuous Air Flow, Ahmed Ali Alkhafaji

Theses and Dissertations

Wastewater treatment is considered one of the most common forms of pollution control in the united states. Considered as an integral part of the wastewater treatment, the aeration process is the most energy-consuming process among all the processes that take place in any wastewater treatment plant. According to the United States Environmental Protection Agency (EPA), a wastewater treatment plant is expected to remove at least 85% of the suspended solids and dissolved organic compounds from the wastewater before discharging it to a river or a lake. The normal operation of the aeration process is by compressing air continuously to basin …


Coral Reef Restoration In The Tropical West Atlantic Amid The Covid-19 Pandemic, Linden Cheek Nov 2020

Coral Reef Restoration In The Tropical West Atlantic Amid The Covid-19 Pandemic, Linden Cheek

USF Tampa Graduate Theses and Dissertations

Climate change is increasing threats to coasts, both from storm surge and sea level rise. Healthy coral reefs provide reduction in storm surges, wave energy, coastal flooding and everyday erosion, and are found across a variety of spatial scales. Given the state of coral reefs worldwide, active Coral Reef Restoration (CRR) in emerging as a necessary component of coastal protection. CRR can be classified as a nature-based solutions (NbS) for coastal protection that also provides a multitude of ecosystem-based services to both humans and other life. Nearly all literature on coral restoration efforts assume a steady-state of human-ecological interactions, but …


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 …


Application Of Artificial Intelligence And Geographic Information System For Developing Automated Walkability Score, Md Mehedi Hasan Aug 2020

Application Of Artificial Intelligence And Geographic Information System For Developing Automated Walkability Score, Md Mehedi Hasan

Dissertations

Walking is considered as one of the major modes of active transportation, which contributes to the livability of cities. It is highly important to ensure walk friendly sidewalks to promote human physical activities along roads. Over the last two decades, different walk scores were estimated in respect to walkability measures by applying different methods and approaches. However, in the era of big data and machine learning revolution, there is still a gap to measure the composite walkability score in an automated way by applying and quantifying the activityfriendliness of walkable streets. In this study, a street-level automated walkability score was …


Black Lives Matter In Engineering, Too! An Environmental Justice Approach Towards Equitable Decision-Making For Stormwater Management In African American Communities, Maya Elizabeth Carrasquillo Jul 2020

Black Lives Matter In Engineering, Too! An Environmental Justice Approach Towards Equitable Decision-Making For Stormwater Management In African American Communities, Maya Elizabeth Carrasquillo

USF Tampa Graduate Theses and Dissertations

The United States and the world have recently been challenged with the disparate effects of COVID-19 and the continual killings of unarmed Black men and women across the nation. A history of anti-black racism has led to systemic structures of inequity that thread throughout institutions and communities across the nation. This environmental engineering research comes at a time when understanding how to effectively engage in, and with Black communities is at the forefront of discourse in academia, utilities and private sector.

In 2018 the Brookings Institute published a report on workforce in the water sector demonstrating the lack of diversity …


Socio-Technical Transitions In The Water Sector: Emerging Boundaries For Utility Resilience In Barbados, Wainella N. Isaacs Jul 2020

Socio-Technical Transitions In The Water Sector: Emerging Boundaries For Utility Resilience In Barbados, Wainella N. Isaacs

USF Tampa Graduate Theses and Dissertations

Resilience is gaining popularity in the water sector where it described as contributing to reduced vulnerability to water-related risks and hazards including climate change. Unfortunately, literature in this area, contributed mainly from North America and Europe, is fragmented with a concentration on engineering resilience in water supply infrastructure. The absence of any scholarship on resilience for a small island nation, coupled with the absence of sociological contributors to building resilience in this sector motivated this research.

The goal of this research was to understand and evaluate how resilience is characterized and operationalized in the Barbados water and wastewater infrastructure system, …


Compound Flooding In Coastal Areas Emanating From Inland And Offshore Events, Hamed Behzad Koochaksaraii May 2020

Compound Flooding In Coastal Areas Emanating From Inland And Offshore Events, Hamed Behzad Koochaksaraii

Dissertations

The vulnerability of urban populations to natural hazards and climate change is a major theme in many reports on coastal cities with flooding ranking highly among the climate change concerns. Flooding could occur as a result of runoff for inland rainfall that accumulates at the mouth of the estuary to the sea or it could occur due to a storm surge emanating from the ocean. The techniques for modeling the flooding from these events are very different, as they were developed in different scientific fields: hydrology and hydraulic engineering for inland rainfall versus coastal oceanography and coastal engineering for offshore …


Space And Depth-Resolved Naturally Occurring Toxic Groundwater Species In Bangladesh And Rwanda: Origination And Risk Analysis, Kenneth Hamilton May 2020

Space And Depth-Resolved Naturally Occurring Toxic Groundwater Species In Bangladesh And Rwanda: Origination And Risk Analysis, Kenneth Hamilton

Civil and Environmental Engineering Theses and Dissertations

Access to safe potable water is a necessity for all. Groundwater is a commonly relied upon drinking water source for many areas around the world. This is especially true for communities in high density, rural settings. Such is the case for populations near Cox’s Bazaar, Bangladesh, and in the Bugesera region of Rwanda. Sediment and groundwater contamination, through toxic dissolved species, represents a significant public health risk to exposed populations. Tropical soils, such as the soil profiles in Bangladesh and Rwanda, often contain higher concentrations of heavy metals (Rieuwerts, 2007). Additionally, nitrate from fertilizers, are widely used on the soils …


Development Of Novel Instrumentation And Methods To Investigate The Composition And Phase Partitioning Of Semivolatile And Intermediately Volatile Organic Compounds In Atmospheric Organic Aerosol, Claire Fortenberry May 2020

Development Of Novel Instrumentation And Methods To Investigate The Composition And Phase Partitioning Of Semivolatile And Intermediately Volatile Organic Compounds In Atmospheric Organic Aerosol, Claire Fortenberry

McKelvey School of Engineering Theses & Dissertations

Atmospheric particulate matter (PM) is ubiquitous in both indoor and outdoor air and is generally detrimental to human health. PM composed of particles with aerodynamic diameters less than 2.5 um (PM2.5) are related to adverse health outcomes including heart disease and respiratory disease. Fundamentally, particle physical properties such as size and hygroscopicity are dictated by chemical composition, which can be highly complex, particularly for organic aerosol (OA). In both outdoor and indoor air, OA is composed substantially of intermediately volatile and semivolatile organic compounds (I/SVOCs), which exist in both gas and particle phases under typical atmospheric conditions. The distribution of …


Chemistry Of Nanoscale Solids And Organic Matter In Sustainable Water Management Systems, Xuanhao Wu May 2020

Chemistry Of Nanoscale Solids And Organic Matter In Sustainable Water Management Systems, Xuanhao Wu

McKelvey School of Engineering Theses & Dissertations

To alleviate global water scarcity and improve public health, engineered water treatment and management systems have been developed for purifying contaminated water and desalinating brackish or ocean water. These engineered systems provide substantial amounts of potable water and lessen environmental concerns about the release of contaminated water. Wastewater treatment plants (WWTPs), water desalination plants (WDPs), and managed aquifer recharge systems (MARs) are three representative sustainable water management (SWM) systems. But the operation of all three poses two fundamental questions: (1) What is the fate of nanoscale solids (e.g., engineered nanomaterials, naturally occurring nanoparticles) in SWM systems and how will their …


Development Of A Hydrodynamic And Sediment Transport Model For Green Bay, Lake Michigan, Bahram Khazaei May 2020

Development Of A Hydrodynamic And Sediment Transport Model For Green Bay, Lake Michigan, Bahram Khazaei

Theses and Dissertations

Sediment dynamics are strongly linked with biogeochemical and physical changes in estuarine systems. Understanding the links between sediment processes and ecosystem responses is necessary for the restoration of degraded systems. Located in Northern US, and one of the largest freshwater estuaries on earth, Green Bay is a distinct example of these degraded systems. Rapid development and anthropogenic activities increased nutrient loading rates into the bay and led to a major disruption of the pre-existing biogeochemical regimes in the ecosystem. Contaminated and nutrient-rich sediments were discharged to the bay by the Fox River for almost half a century. Green Bay’s seasonal-, …


Irrigation Design In Montana: Accommodating Varying Water Accessibility Across The Continental Divide., John Garrett Lampson May 2020

Irrigation Design In Montana: Accommodating Varying Water Accessibility Across The Continental Divide., John Garrett Lampson

Biological and Agricultural Engineering Undergraduate Honors Theses

The design work performed in this project was conducted over two summers (2018, 2019) of internship experience with the Natural Resources Conservation Service (NRCS) across the state of Montana. The first summer’s design work was based out of Glendive, MT, in Dawson County, approximately 50 kilometers from the North Dakota border. The second summer was in Missoula, MT, in Missoula County, near the Idaho border. The two areas differ significantly in topography, weather, and water availability with the main separating geographic influence being the Rocky Mountains.

This paper focuses on the design process and requirements for two farms located outside …


Surface Modified Polypropylene Membranes For Treating Hydraulic Fracturing Produced Waters By Membrane Distillation, Tharaka Hawpe Gamage May 2020

Surface Modified Polypropylene Membranes For Treating Hydraulic Fracturing Produced Waters By Membrane Distillation, Tharaka Hawpe Gamage

Graduate Theses and Dissertations

Membrane distillation is an emerging technology for treating hydraulic fracturing flowback and produced waters. Suppression of membrane fouling by inorganic and polar and non-polar organic compounds is a challenge. Here polyhydroxyethyl methacrylate, polyacrylic acid, polvinylallyl imidazolium bromide and polyvinylhexyl imidazolium bromide chains have been grafted from the membrane surface. Fouling is initially due to adsorption of organic compounds followed by scale formation. When challenged with produced water, membranes modified with polvinylallyl imidazolium bromide chains provided the greatest resistance to fouling. For EC pretreated produced water and synthetic produced water that contained mainly inorganic species, the flux decline was much less.


Abiotic, Biotic, And Bio-Enhanced Reduction Of Hexavalent Chromium, Chloroform And Co-Contaminants Using Nano-Scale Zero Valent Iron In Highly Contaminated Groundwater, Eduardo Robleto Martinez May 2020

Abiotic, Biotic, And Bio-Enhanced Reduction Of Hexavalent Chromium, Chloroform And Co-Contaminants Using Nano-Scale Zero Valent Iron In Highly Contaminated Groundwater, Eduardo Robleto Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Investigations of groundwater in a former industrial perchlorate manufacturing site have shown high contamination with perchlorate, chlorate, nitrate, hexavalent chromium (Cr (VI)), and chloroform (CF) with levels greater than 3,000, 30,000, 300, 100, and 4 mg/L, respectively. Remediation efforts using biological reduction to desired contaminant levels at this site has been challenging due to high contaminant concentrations, and high total dissolved solids (TDS). Furthermore, removal of Cr(VI) and CF in the presence of nitrate, chlorate, and perchlorate has not been examined at the contaminated site. Nano-scale Zero-Valent-Iron (NZVI) has been effective at reducing groundwater contamination both with and without bacterial …


Water Supply Capacity Development In The Context Of Global Change, Patrick Breach Apr 2020

Water Supply Capacity Development In The Context Of Global Change, Patrick Breach

Electronic Thesis and Dissertation Repository

The ANEMI model is an integrated assessment model of global change that emphasizes the role of water resources. The model is based on the principles of system dynamics simulation in order to analyze changes in the Earth system using feedback processes. Securing water resources for the future is a key issue of global change, and ties into global systems of population growth, climate change carbon cycle, hydrologic cycle, economy, energy production, land use and pollution generation.

This thesis focusses on the development of global water supplies necessary to keep pace with a growing population and global economy using an integrated …


The Siltcatcher: A Sediment-Capture System For Wetland Creation And Coastal Protection In Western Lake Pontchartrain, Andrew M. Wright Apr 2020

The Siltcatcher: A Sediment-Capture System For Wetland Creation And Coastal Protection In Western Lake Pontchartrain, Andrew M. Wright

LSU Master's Theses

The West Lake Pontchartrain region faces a number of long-term environmental challenges due to anthropogenic climate disturbance and landscape modification, including sea level rise, increased storm surge risk, shoreline erosion, and wetland degradation. In response, this thesis applies recent research in the fields of landscape architecture and civil engineering to propose a dynamic, natural-systems solution for wetland creation and shoreline protection. The project envisions a series of breakwater-like structures in western Lake Pontchartrain positioned to slow water released from the nearby Bonnet Carré Spillway, causing suspended sediment to settle and create self-building and self-sustaining wetlands capable of keeping pace with …


Lignin: A Likely Precursor Of A Significant Fraction Of Humic Substances Via Oxidative Transformations, Seyyedhadi Khatami Apr 2020

Lignin: A Likely Precursor Of A Significant Fraction Of Humic Substances Via Oxidative Transformations, Seyyedhadi Khatami

Chemistry & Biochemistry Theses & Dissertations

Lignin is a major component of decaying terrestrial vegetation in soils and has been arguably reported to contribute substantially to the formation of soil carbon humus, and natural dissolved organic matter (DOM). To better understand the process by which this humification occurs, lignin and lignin-derived monomers were subjected to both biotic and abiotic oxidation processes. Two well-known oxidative transformation strategies were employed. The first involved the fungal degradation of brown-rot degraded wood subjected to a white-rot fungus (Phanerochaete chrysosporium) whose enzymes are particularly effective in lignin degradation via enzymatic oxidation. This enzymatic attack was monitored by ultrahigh resolution …


Quantification Of Septic System Contribution To Nutrient Loads In Surface Waters, Archana Tamang Mar 2020

Quantification Of Septic System Contribution To Nutrient Loads In Surface Waters, Archana Tamang

Electronic Thesis and Dissertation Repository

Freshwater systems worldwide are threatened by excessive nutrient (nitrogen and phosphorus) loading. This study evaluated the contribution of septic systems to stream nutrient loads in nine subwatersheds. Stream sampling was conducted during low and high discharge conditions, with samples analyzed for total phosphorus (TP), soluble reactive phosphorus (SRP), nitrate (NO3-N), and acesulfame (ACE; wastewater tracer). Higher septic effluent reached the subwatershed outlets during high discharge conditions. Subwatersheds with newer households had a lower percentage of septic effluent reaching the stream compared with subwatersheds with older households. Seasonal and event-based ACE concentration-discharge relationships revealed that the hydrological pathways delivering …


An Analysis Of Tinker Air Force Base Thermal Spray Hazardous Waste Stream From 2003-2019 And Its Potential Reclamation, Amy E. Silverbush Mar 2020

An Analysis Of Tinker Air Force Base Thermal Spray Hazardous Waste Stream From 2003-2019 And Its Potential Reclamation, Amy E. Silverbush

Theses and Dissertations

The disposal of hazardous waste threatens the environment and human health. However, certain hazardous wastes can be recycled or reclaimed to alleviate environmental and financial impacts associated with its disposal and resource demand reduction. A hazardous powder produced by the United States Air Force stems from aircraft maintenance and is composed of metals and ceramics, called thermal spray. This waste can be purchased by an industrial recycler if the waste is composed of valuable metals. Historic data from the depot-level maintenance base Tinker Air Force Base initiated an analysis of annual thermal spray hazardous waste disposal fees, which combined with …


Adapting To Extreme Heat: Social, Atmospheric, And Infrastructure Impacts Of Air Conditioning In Megacities - The Case Of New York City, Harold Gamarro Jan 2020

Adapting To Extreme Heat: Social, Atmospheric, And Infrastructure Impacts Of Air Conditioning In Megacities - The Case Of New York City, Harold Gamarro

Dissertations and Theses

Extreme heat events are becoming more frequent and intense in most large cities. Built-up surfaces also limit cooling mechanisms, leading to warmer conditions in cities, a phenomenon called the Urban Heat Island (UHI). This presents major challenges to reduce adverse health effects of hot weather, particularly in vulnerable populations like the elderly and low-income communities. Here we explore the overall impacts of increasing air conditioning (AC) system adoption in residences as an adaptive measure to reduce human health risks under heat waves, with New York City (NYC) as a case study. This study uses AC adoption data from the 2017 …


A Modeling Approach To Understanding Glyphosate Transport In The Belize River Watershed, Barbara Anmei Astmann Jan 2020

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 …


Chemically Stabilized Oil-In-Water Emulsion Separation Using A Custom Aquaporin-Based Polyethersulfone (Pes) Forward Osmosis Membrane System, Annmarie Ricchino Jan 2020

Chemically Stabilized Oil-In-Water Emulsion Separation Using A Custom Aquaporin-Based Polyethersulfone (Pes) Forward Osmosis Membrane System, Annmarie Ricchino

Electronic Theses and Dissertations, 2020-

The stability of oil-in-water emulsions is enhanced by the presence of surfactants in the water, thereby increasing difficulty of remediation. In this study, mineral oil and a standard bilge mix (SBM) were used as model oils for forward osmosis (FO) performance evaluation and two different high-concentration feed solutions (FS) were tested: 10,000 and 100,000 ppm oil/surfactant (9:1 Oil/Surfactant, wt %). It was hypothesized that the charge-charge interactions between the surfactant portion of the micelles and the membrane would play an important role in membrane fouling. Therefore, the effects of both an anionic surfactant (sodium dodecyl sulfate [SDS]) and a nonionic …


Emulsion Characterization Study For Improved Bilgewater Treatment And Management, Daniela Diaz Hernandez Jan 2020

Emulsion Characterization Study For Improved Bilgewater Treatment And Management, Daniela Diaz Hernandez

Electronic Theses and Dissertations, 2020-

The need for proper management of bilgewater to meet discharge regulations (e.g., 15 ppm oil) has revealed the necessity to expand the current understanding of bilgewater emulsions. This study proposed to evaluate emulsion stability under various environmental conditions and to identify governing parameters for emulsion formation. The stabilizing properties of eight-commercial cleaners and two-neat surfactants were evaluated. In situ characterization techniques were used for monitoring emulsion stability. Additionally, a needle-type pH microsensor and fluorescence spectroscopy were used for analyzing mass transfer at the oil-water interface. Water quality of extracted bilgewater showed to highly vary between vessels (e.g., conductivity: 1.74 -- …


Ultraviolet Irradiation Combined With Chlorine Dioxide Pre-Oxidation For Disinfection By-Product Control, Paula Campesino Jan 2020

Ultraviolet Irradiation Combined With Chlorine Dioxide Pre-Oxidation For Disinfection By-Product Control, Paula Campesino

Electronic Theses and Dissertations, 2020-

The use of ultraviolet (UV) light and chlorine dioxide (ClO2) as an advanced oxidation process (AOP) has been investigated at the bench-scale to understand the effects of their use on disinfection by-product (DBP) formation potential (FP) in chlorinated groundwater (GW) and surface water (SW) supplies. Two GWs and two SWs of varying qualities were subject to a series of AOP treatment sequences at the bench scale: sodium hypochlorite, to serve as a baseline; ClO2-Cl2, UV-Cl2, and UV-ClO2-Cl2. In these treatment sequences, Cl2 is used as a primary and secondary disinfectant. Several water quality parameters were measured throughout the experiments, including …


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 Jan 2020

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 …


Life Cycle Studies To Evaluate The Physiological And Biochemical Effects Of Copper Oxide And Surface-Coated Titanium Dioxide Nanoparticles On Green Onion (Allium Fistulosum) And Carrot (Daucus Carota L.) Plants: Insights Utilizing Two-Photon Microscopy And Spectroscopy, Yi Wang Jan 2020

Life Cycle Studies To Evaluate The Physiological And Biochemical Effects Of Copper Oxide And Surface-Coated Titanium Dioxide Nanoparticles On Green Onion (Allium Fistulosum) And Carrot (Daucus Carota L.) Plants: Insights Utilizing Two-Photon Microscopy And Spectroscopy, Yi Wang

Open Access Theses & Dissertations

With the recent increase of nanomaterial production, nano copper oxide (nCuO) and surface-modified titanium dioxide nanoparticles (nTiO2) are among the most widely applied nanoparticles in industry and daily lives. Their use has resulted in accumulation in soils as a consequence of their direct or indirect release. Hence, these NPs may raise a potential risk to crops cultivated in soils. Moreover, the physiological effects of nCuO on green onion (Allium fistulosum) and surface-coated nTiO2 on full-grown carrot (Daucus carota L.) are still unknown. Green onion is characterized by its high content of the antioxidant allicin, and carrot is a worldwide economic …