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Adaption Of Catechol And Reversible Addition-Fragmentation Chain-Transfer (Raft) Chemistries For Water-Based Applications, Olabode Oyeneye

Electronic Thesis and Dissertation Repository

Incorporating the binding chemistry of catechol functionality with RAFT chemistry offers a facile and simplified approach for developing a suite of new 2D and 3D hybrid materials with tailored morphologies. Leveraging both chemistries by synthesizing catechol-end functionalized RAFT agents and catechol-containing monomeric species for RAFT (co)polymerization, this dissertation examined a new series of advanced materials that were designed for water-based applications including model flocculants, thermoresponsive hydrogels, adsorbents and underwater adhesives.

To prepare the RAFT agents, novel trithiocarbonates with several catechol end R groups (as postpolymerization anchors) were synthesized that differ in their carbonyl α-substituents (Dopa-CTAs). These materials were evaluated for …

Moving Bed Biofilm Reactors: Evaluation Of Geometry, Attachment Surface Material And Biofilm Populations On The Uptake Of Ammonia And Synthetic Organic Contaminants In Wastewater., Patrick D. Mclee

Civil Engineering ETDs

Plastic biofilm carriers are used in biological wastewater treatment to encourage the attachment and retention of microorganisms that metabolize pollutants. The following research was conducted to better understand how different characteristics of the biofilm carrier affect the treatment performance of the attached biofilms in moving bed bioreactors. Lab scale reactors were used in this study to grow nitrifying biofilms in reactors with contrasting and controlled conditions. The effect of surface geometry on nitrification performance was evaluated by testing commercially available moving bed bioreactor media that contrast in physical design, and by varying operational parameters. Additionally, mature biofilm from a similar …

Multi-Scale Studies To Develop A Holistic Understanding Of Solid Fuel Combustion At Residential Scale, Sameer Patel

McKelvey School of Engineering Theses & Dissertations

Nearly 3 billion people rely on solid fuels for their cooking and heating needs, classifying them as “energy poor”. This poverty can be attributed to several factors, including a lack of resources (fuel), inefficient infrastructure (production and distribution), limited purchasing power (poverty), and ill-devised policies. Solid fuels, such as biomass, coal, and dung cakes, are burned in inefficient cookstoves. They generate products of incomplete combustion (PIC), such as CO, particulate matter (PM), and CH4, causing household air pollution (HAP) whose adverse impacts on both health and the environment have been well established.

HAP causes diseases such as chronic obstructive pulmonary …

Coupling Of Oxidation-Reduction Reactions Of Chromium, Iron And Manganese: Implications For The Fate And Mobility Of Chromium In Aquatic Environments, Chao Pan

McKelvey School of Engineering Theses & Dissertations

Both within the United States and internationally, hexavalent chromium (Cr(VI)) is a contaminant of concern in drinking water supplies. The U.S. Environmental Protection Agency is considering a Cr(VI)-specific standard. Thus improved technologies for Cr(VI) removal in drinking water are needed. Iron electrocoagulation for Cr(VI) removal was examined at conditions directly relevant to drinking water treatment, and humic acid (HA) affects the performance of electrocoagulation in multiple ways. The success of the chromium treatment or remediation also relies on the stability of the Cr(III)-containing solids with respect to reoxidation under groundwater conditions. Manganese is ubiquitous in aquatic and terrestrial environments, and …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

Modelling Of Future Flood Risk Across Canada Under Climate Change, Ayushi Gaur

Electronic Thesis and Dissertation Repository

Climate change has induced changes in key climate variables and hydrological cycle in Canada. In this study, future runoff projections made by 21 GCMs following four Representative Concentration Pathways (RCPs) are used as inputs into a macro-scaled hydrodynamic model: CaMa-Flood to simulate 25 km resolution daily streamflow across Canada for historical (1961-2005) and future (2061-2100) time-periods. Future changes in flood-hazard as a consequence of changes in flooding frequencies of historical 100-year and 250-year return period flood events, and changes in the month of occurrence of extreme flows are analyzed. Changes in flood risk at Canada’s 100 most populous cities and …

Investigating Fate Of Silver Nanoparticles In Wastewater Biofilms, Connie Marie Walden

Graduate Theses and Dissertations

As industrial advances make everyday life easier for human kind, the processes by which we need to maintain sanitary conditions for both water and wastewater treatment will become increasingly complex. Innovations in food packaging and textile design incorporate engineered nanoparticles (ENPs) to increase antimicrobial properties of clothing, maintain product color, and keep food in packaging from spoilage. For most products, ENPs released will enter the sanitary sewer system, and ultimately wastewater treatment plants. Biofilms grow universally on surfaces where a protective layer of extracellular polymeric substances (EPS) shields attached cells from stressors. In wastewater treatment, complex biofilms are utilized as …

Water Chemistry Dynamics In Four Vernal Pools In Maine, Usa, Lydia H. Kifner

Electronic Theses and Dissertations

Vernal pools are small seasonal wetlands that are a common landscape feature that contribute to biodiversity in northeastern North American forests. However, even basic information about their biogeochemical functions, such as carbon cycling, is limited. Dissolved gas concentrations (CH₄, CO₂) and other water chemistry parameters were monitored weekly at the bottom and surface of four vernal pools in central and eastern Maine, USA, from April to August 2016. The vernal pools were supersaturated with respect to CH₄ and CO₂ at all sampling dates and locations. Concentrations of dissolved CH₄ and CO₂ ranged …

Development Of Pre-Stressed Retrofit Strategies For Mitigating Fatigue Cracking In Steel Waterway Lock Gate Components, Christine Michelle Lozano

Graduate Theses and Dissertations

Lock gates are an important part of the transportation infrastructure within the United States (US), having many economic, safety, and environmental benefits over rail and highway transportation systems. Unfortunately, many existing lock gates throughout the US have reached or exceeded their initial design life and require frequent repairs to remain in service. Unscheduled repairs often increase as gates age, having a local economic impact on freight transport which can create economic ripples throughout the nation. Fatigue and corrosion are key causes of unscheduled service interruptions, degrading lock gate components over time. Additionally, because lock gates are submerged during operation, crack …

Real-Time, Selective Detection Of Heavy Metal Ions In Water Using 2d Nanomaterials-Based Field-Effect Transistors, Guihua Zhou

Theses and Dissertations

Excessive intake of heavy metals damages the central nervous system and causes brain and blood disorders in mammals. Heavy metal contamination is commonly associated with exposure to mercury, lead, arsenic, and cadmium (arsenic is a metalloid, but classified as a heavy metal). Traditional methods to detect heavy metal ions include graphite furnace atomic absorption spectroscopy (GFAAS), inductively-coupled plasma optical emission spectroscopy (ICP-OES), and inductively-coupled plasma mass spectroscopy (ICP-MS). Recently, many new methods have been proposed to detect heavy metal ions, including atomic absorption spectrometry, fluorescent sensors, colorimetric sensors, electrochemical sensors, X-ray absorption fine structure spectroscopy, ultrasensitive dynamic light scatting assays, …

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …

Understanding The Long-Term Changes In Hydrologic Processes On A Watershed Scale Due To Climate Variability And Change, Chao Chen

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the past century, the population explosion and economic development have resulted in global warming, which has raised a series of concerns, such as sea-level rise, food security, and water resources management. The water flow patterns and features experience both short-term and long-term changes in responses to the changes in the hydrologic processes and meteorologic conditions. On a watershed scale, it is crucial to understand, quantify, and attribute the influences of climate change on the local water resources system. Such understanding can be of great help to undertake local water management tasks, such as flood control, reservoir operation, ecosystem services, …

Evaluating The Chemical And Biological Stability Of Finished Waters Blended For Direct Potable Reuse In A Simulated Distribution System, Assumption Grimaldi

UNLV Theses, Dissertations, Professional Papers, and Capstones

This work evaluated the impacts of blending several different high grade recycled waters with conventional source waters for direct potable reuse (DPR) applications. Bench-scale laboratory tests were conducted for recycled water-source water blends from four participating facilities that have either considered adopting DPR or have already implemented DPR as a feasible approach to overcome water scarcity. The chemical and biological stability of the finished waters was investigated after pipe rig incubation to simulate the quality of blended waters that had aged in a potable water distribution system. The effects of blend ratio, reclaimed water treatment, and source water quality were …

Understanding The Linkages Between Urban Transportation Design And Population Exposure To Traffic-Related Air Pollution: Application Of An Integrated Transportation And Air Pollution Modeling Framework To Tampa, Fl, Sashikanth Gurram

USF Tampa Graduate Theses and Dissertations

Rapid and unplanned urbanization has ushered in a variety of public health challenges, including exposure to traffic pollution and greater dependence on automobiles. Moreover, vulnerable population groups often bear the brunt of negative outcomes and are subject to disproportionate exposure and health effects. This makes it imperative for urban transportation engineers, land use planners, and public health professionals to work synergistically to understand both the relationship between urban design and population exposure to traffic pollution, and its social distribution. Researchers have started to pay close attention to this connection, mainly by conducting observational studies on the relationship between transportation, urban …

Hydrogeochemical Investigation Of Recharge Pathways To Intermediate And Regional Groundwater In Cañon De Valle And Technical Area 16, Los Alamos National Laboratory, Brendan W. Brady

Civil Engineering ETDs

In aquifers consisting of fractured or porous igneous rocks, as well as conglomerate and sandstone products of volcanic formations, silicate minerals actively dissolve and precipitate (Eby, 2004; Eriksson, 1985; Drever, 1982). Dissolution of hydrated volcanic glass is also known to influence the character of groundwater to which it is exposed (White et al., 1980). Hydrochemical evolution, within saturated zones of volcanic formations, is modeled here as a means to resolve the sources feeding a perched groundwater zone. By observation of solute mass balances in groundwater, together with rock chemistry, this study characterizes the chemical weathering processes active along recharge pathways …

Development Of Artificial Intelligence Approach To Nowcasting And Forecasting Oyster Norovirus Outbreaks Along The U.S. Gulf Coast, Shima Shamkhali Chenar

LSU Doctoral Dissertations

Oyster norovirus outbreaks pose increasing risks to human health and seafood industry worldwide. This study presents an Artificial Intelligence (AI)-based approach to identifying the primary cause of oyster norovirus outbreaks, nowcasting and forecasting the growing risk of oyster norovirus outbreaks in coastal waters. AI models were developed using Artificial Neural Networks (ANNs) and Genetic Programming (GP) methods and time series of epidemiological and environmental data. Input variable selection techniques, including Random Forests (RF) and Forwards Binary Logistic Regression (FBLR), were used to identify the significant model input variables among six independent environmental predictors including water temperature, solar radiation, gage height, …

The Control Of Water Contaminants Assisted By Natural Materials, Wen Zhao

USF Tampa Graduate Theses and Dissertations

Natural materials can be used to remove water contaminants by applying proper physical, chemical, and biological water treatment processes. This study involves using natural materials, as they are considered to be more environmentally benign and cost-effective than synthetic materials. This dissertation concentrates on monitoring five major water quality parameters—ammonia, fluoride, turbidity, pH, and fecal indicator bacteria (FIB) —in two major applications where clean water is needed. The focus is on meeting the water quality requirements for each contaminant. The overall objective of this study is to control the levels of ammonia in aquaculture wastewater, and adjust fluoride, turbidity, pH, and …

Selecting Technological Alternatives For Regulatory Compliance Towards Emissions Reduction From Shipping: An Integrated Fuzzy Multi-Criteria Decision-Making Approach Under Vague Environment, Khanh Quang Bui

World Maritime University Dissertations

No abstract provided.

Water, Sanitation, And Citizenship: Perceptions Of Water Scarcity, Reuse, And Sustainability In Valparaiso De Goias, Brazil, Paola Andrea Gonzalez

USF Tampa Graduate Theses and Dissertations

Access to reliable water and sanitation are two important goals to improve livelihoods around the world. Providing access to improved and safe water resources that are equitable and appropriate to local needs is important to improve sustainability long-term. In addition, framing access to water and sanitation as basic human rights is often used as a rationale in developing new water, sanitation, and hygiene interventions in developing countries around the world. But not all countries consider access to safe water and sanitation as a human right. In the thesis, the politics of improving and investment in water access and sanitation provision …

Enhancement Of Two Passive Decentralized Biological Nitrogen Removal Systems, Justine L. Stocks

USF Tampa Graduate Theses and Dissertations

This research evaluates two different Biological Nitrogen Removal (BNR) systems for enhanced nitrogen removal in decentralized wastewater treatment. The first study evaluated the performance of Hybrid Adsorption and Biological Treatment Systems (HABiTS) at the pilot scale with and without stage 1 effluent recirculation. HABiTS is a system developed at the bench scale in our laboratory and was designed for enhanced BNR under transient loading conditions. It consists of two stages; an ion exchange (IX) onto clinoptilolite media coupled with biological nitrification in the aerobic nitrification stage 1 and a Tire-Sulfur Adsorption Denitrification (T-SHAD) system in the anoxic denitrification stage 2. …

Microbial Competition In Bioelectrochemical Systems, Varun Srinivasan

Doctoral Dissertations

Bioelectrochemical systems(BESs)/ microbial fuel fells (MFCs) are a well-studied potential technology for bioremediation and decentralized wastewater treatment. However, progress has been somewhat stalled at the bench-scale. In well controlled experiments electron recovery is high. In natural environments, wastewaters are complex and anode-respiring bacteria can be outcompeted in the presence of competing microorganisms, leading to a loss in electron-recovery and power production. Furthermore, the cathode of the MFC plays a vital role in providing flexibility for treatment options but is an understudied part of MFCs. Modelling Intracellular Competition in a Denitrifying Biocathode: One potential MFC configuration uses an organic-oxidizing anode biofilm …

Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel

Doctoral Dissertations

A uniform dispersion of reactants is necessary to achieve a complete reaction involving multi-components, especially for the crosslinking of rigid high-performance materials. In these reactions, miscibility is crucial for curing efficiency. This miscibility is typically enhanced by adding a third component, a plasticizer. For the reaction of the highly crystalline crosslinking agent hexamethylenetetramine (HMTA) with a strongly hydrogen-bonded phenol formaldehyde resin, furfural has been traditionally used as the plasticizer. However, the reason for its effectiveness is not clear. In this doctoral thesis work, miscibility and crosslinking efficiency of plasticizers in phenolic curing reactions are studied by thermal analysis and spectroscopic …

Decision Analytical Methods For Robust Water Infrastructure Planning Under Deep Uncertainty, Mehmet Umit Taner

Doctoral Dissertations

Deep uncertainties resulting from climate change, demographic pressures, and rapidly evolving socioeconomic conditions are challenging the way that water planners design and operate large-scale infrastructure systems. Conventionally, water infrastructures have been developed using stationary methods, assuming that the underlying uncertainties can be derived from historical data or experience. However, these methods are less useful under deeply uncertain climate and socioeconomic conditions, in which the future can be substantially different from the past and cannot be expressed by well-defined probability distributions. The recognition of deep uncertainties in long-term water resources planning has led to the development of “decision-analytical” frameworks that do …

Microbial Dynamics And Design Considerations For Decentralized Microbial Fuel Cell Applications, Cynthia Castro

Doctoral Dissertations

The purpose of this dissertation was to assess the practicality of using microbial fuel cells (MFCs) as alternative sanitation systems for wastewater treatment and energy recovery, focusing on identifying key design considerations for treating high strength wastewater and managing alternative metabolic pathways. We evaluated the energetic outputs of a lab-based pilot MFC designed to treat complex organics present in both synthetic feces and municipal wastewater. The pilot MFC produced two energetic products, methane and electricity, when treating two types of complex wastewaters. The energetic products associated with anode respiration and methanogenesis were simultaneously observed and yielded a combined energy ouput …

Optimizing Stabilized Fluorogypsum To Decrease Dissolution Potential In Aquatic Environments For Construction Of Artificial Reefs, Charles Davis Lofton

LSU Doctoral Dissertations

The use of limestone as coastal protection devices and as an oyster cultch material has placed a substantial economic burden on the State of Louisiana. Limestone is not locally available in the State of Louisiana and must be transported from out of state which significantly increases the cost of utilizing the material. Placement of limestone on the unconsolidated soils in coastal Louisiana result in significant losses to sinking of the material due to the density of limestone. Therefore, locally available materials with a lower density compared to limestone are needed to reduce the economic burden of protecting and enhancing coastlines. …

Enumeration, Variability, And Transport Of Escherichia Coli In The Foreshore Reservoir And Surface Water At Freshwater Beaches, Laura J. Vogel

Electronic Thesis and Dissertation Repository

Beaches are of immense recreational, societal and economic value. This value, however, is considerably diminished by poor water quality. Fecal indicator bacteria (FIB) are measured at recreational beaches worldwide to assess the water quality. A beach closure or advisory is issued if FIB concentrations in surface water exceed recreational water quality standards. Due to the lengthy time required to enumerate FIB (24 – 96 hours), statistical and mechanistic models have been developed to predict water quality exceedances a priori and to better understand why and under what conditions water quality exceedances occur. These models as well as beach water quality …

Elution Tailing Of Nonaqueous Phase Liquids In Porous Media, Louisa Orr

Civil and Environmental Engineering Undergraduate Honors Theses

A variety of porous media were studied to characterize contaminant dispersion over time. This work looked at a compilation of previously published studies to investigate the dependence of long term elution tailing trends on particular soil characteristics. Recession curve analysis was conducted on existing dispersed contaminant literature, to yield the low-concentration recession constant (K). The R² values correlating the soil properties to contaminant concentration ranged from 0.12494 to 0.95429. The low-concentration recession constant (K) values ranged from 0.9745407 0.9999988. The relationship between K and the soil properties porosity, organic carbon, and fines fraction is increasing. Bulk density and the …

Quantifying Pollutant Removal Rates Of Bioretention Basins As A Stormwater Best Management Practice, Evan Nathanial Waagen

Civil & Environmental Engineering Theses & Dissertations

Water pollution is an ongoing problem that can be attributed to human activities. As world population increases and countries become more developed, this problem intensifies. Fortunately, the causes and solutions of water pollution are documented and have been implemented with various levels of success. These solutions, or Best Management Practices (BMPs), vary in type and function and remove pollutants from runoff prior to it reaching rivers, lakes, and other bodies of water. This study investigates bioretention basins, a specific group of BMPs, and presents analysis and prediction of their performance, of which our knowledge is incomplete in the existing literature. …

Holistic Approach In Microalgae Conversion To Bioproducts And Biofuels Through Flash Hydrolysis, Ali Teymouri

Civil & Environmental Engineering Theses & Dissertations

In recent years, the demand for renewable energy, mainly biomass has increased. The U.S. Energy Information Administration reported that more than 13.3% of the total energy production in the first seven months of 2017 was produced from a biomass source. Among all biomass resources, microalgae has brought a lot of attention due to their numerous advantages such as higher growth rate and productivity compared with the conventional energy crops, higher energy conversion efficiency by photosynthesis, and less water requirement than terrestrial crops. However, its development is far behind industrial production. Several research efforts across the globe have been concerned with …

The Development And Numerical Modelling Of A Representative Elemental Volume For Packed Sand, Ashraf Thabet

Electronic Thesis and Dissertation Repository

The motivation of this thesis is the development of simple microscopic-scale model (representative elemental volume; REV) that can be used to conduct flow and heat transfer simulations from which closure coefficients can be established for the volume-averaged transport equations for porous media (packed bed). The thesis provides a brief introduction to the computational technique adopted for the geometric generation of the REV (YADE), followed by a parametric study undertaken to reveal the minimum number of particles inside the REV that are required to mimic the appropriate physics. Additional analysis was conducted with the goal of determining the influence of deviation …