Digital Commons Network^™

Improved 2d And 3d Resistivity Surveys Using Buried Electrodes And Optimized Arrays: The Multi-Electrode Resistivity Implant Technique (Merit), Henok Gidey Kiflu

USF Tampa Graduate Theses and Dissertations

This thesis presents a novel resistivity method called Multi-Electrode resistivity technique (MERIT) that is used for high resolution imaging of complex geologic features at depth and near the edges of survey lines. The MERIT electrodes are especially shaped and designed to be self-driven using a robust-direct push technique. Measurements are taken using optimized arrays that are generated using a modified version of the “Compare-R” optimization algorithm. This work focused on both two-dimensional (MERIT2D) and three-dimensional (MERIT3D) applications of the buried array and show the relevance of the additional information gained by the addition of deep electrodes especially in sites with …

Advancements In Thermal Integrity Profiling Data Analysis, Kevin Russell Johnson

USF Tampa Graduate Theses and Dissertations

Thermal Integrity Profiling (TIP) is a relatively new non-destructive test method for evaluating the post-construction quality of drilled shafts. Therein anomalies in a shaft are indicated by variations in its thermal profile when measured during the curing stages of the concrete. A considerable benefit with this method is in the ability to detect anomalies both inside and outside the reinforcement cage, as well as provide a measure of lateral cage alignment. Similarly remarkable, early developments showed that the shape of a temperature profile (with depth) matched closely with the shape of the shaft, thus allowing for a straightforward interpretation of …

Development Of An Anaerobic-Phototrophic Bioreactor System For Wastewater Treatment, Onur Yilmaz Ozcan

USF Tampa Graduate Theses and Dissertations

For decades, mainstream domestic wastewater treatment has relied on activated sludge processes to remove organic matter, and on biological nutrient removal systems like the A²/O process to remove nutrients. Recently, membrane filtration was also added to the realm of possible technologies for domestic wastewater treatment, with aerobic membrane bioreactors (MBRs) becoming increasingly popular, especially for decentralized, and small to medium scale applications. However, the aerobic activated sludge and MBR processes, which are often combined with biological nutrient removal processes, have high energy costs associated with supplying oxygen to the process, and end up converting the organic matter into …

Effective Post-Tensioned Splicing System For Prestressed Concrete Piles, Zhongxin Wu

USF Tampa Graduate Theses and Dissertations

Precast prestressed concrete piles are widely used in deep foundation construction. Due to unexpected site soil conditions and difficulties associated with transportation and handling long precast piles, splicing is sometimes necessary at the construction site.

Available splicing methods utilize steel type connections that are more suitable for reinforced concrete construction and result in limited tensile capacity at the splice. This dissertation describes studies associated with the development of a new post-tensioned splicing system using staggered, embedded anchorages. The new system has the potential to provide the same tensile capacity as a one piece prestressed pile.

To develop the post-tensioned splicing …

Pepper Mild Mottle Virus As A Surrogate For Enteric Viruses: Implications For Assessing Water Quality, Erin Michelle Symonds

USF Tampa Graduate Theses and Dissertations

Less than 10% of the world’s domestic wastewater is disinfected prior to discharge into surface waters; therefore, human exposure to diverse wastewater-related pathogens results in millions of cases of illness each year. Among the enteric pathogens, viruses represent an important group of emerging pathogens and are frequently the cause of food- and water-borne outbreaks of illness. Although the World Health Organization and many government agencies mandate the use of bacterial indicators to identify poor microbial water quality, it is well known that these indicators poorly correlate with fecal pollution contamination events and risk of disease. The field of public health-related …

Cracking Potential And Temperature Sensitivity Of Metakaolin Concrete, Andrew Robert Williams

USF Tampa Graduate Theses and Dissertations

Metakaolin is a pozzolanic material with the potential to reduce permeability and chloride ingress; however, quantification of the effects of metakaolin use on the cracking sensitivity of concrete mixtures is needed to ensure that these improvements in performance are not compromised. This study was conducted to investigate the early age cracking potential due to restraint stresses from incorporating metakaolin in concrete. Calorimetry testing showed that metakaolin was more sensitive to temperature than mixtures with only Portland cement. Results showed more shrinkage, less stress relaxation, and higher restraint stress from the inclusion of metakaolin, potentially increasing cracking sensitivity of mixtures.

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Formation Of Trihalomethanes (Thms) As Disinfection By-Products (Dbps) When Treated Municipal Wastewater Is Disinfected With Sodium Hypochlorite, Helene Kassouf

USF Tampa Graduate Theses and Dissertations

Disinfection is an essential process in the treatment of municipal wastewater before the treated wastewater can be discharged to the environment. Hillsborough County's Northwest Regional Water Reclamation Facility (NWRWRF) in Tampa, Florida, currently uses ultraviolet (UV) light for disinfection. However, this method has proven expensive to implement and maintain, and may not be effective if the light transmission is poor. For these reasons, Hillsborough County is considering switching from UV light to sodium hypochlorite for disinfection. However, hypochlorite (chlorine) disinfection has disadvantages as well, such as the production of disinfection by-products (DBPs) such as trihalomethanes (THM) and haloacetic acids (HAAs), …

The Effect Of The Antecedent Dry Conditions On Nitrogen Removal For A Modified Bioretention System, Mackenzie Peterson

USF Tampa Graduate Theses and Dissertations

Eutrophication is defined as the ‘over enrichment’ of a water body from nutrients, resulting in uncontrolled growth of primary producers, leading to periods of oxygen depletion from decomposition of the algal organic matter. According to the 2010 Water Infrastructure Needs and Investment (a U.S. Congressional Report), 40% of U.S. water bodies are contaminated with pollutants, including nutrients. Non-point sources of nutrient pollution are a major cause of this reduction in water quality. One way to decrease eutrophication is to manage nutrients found in stormwater runoff, before they reach a receiving water body.

Bioretention cells containing an internal water storage zone …

Time Dependent Effect Of Drilling Slurries On Side Shear Resistance Of Drilled Shafts, Warren Allen

USF Tampa Graduate Theses and Dissertations

Drilled shafts are cylindrical deep foundations constructed by casting fluid concrete into an excavated hole. These elements rely largely on side shear resistance generated by their substantial diameters and lengths to effectively transfer loads. Therefore, an exceptional concrete to soil interface is essential for proper performance of these structures. The FDOT preferred stabilization fluid, bentonite slurry, has been proven to degrade this interface with increased exposure time due to filter cake formation. For this reason, slurry exposure time has been limited to 36 hours by FDOT. Alternately, polymer slurries do not form a filter cake but rather stabilize excavations through …

Investigation Of Future Flow Reducer Sizes In Houses Added To An Existing Gravity Flow Water System To Ensure Its Sustainability, Michelle Roy

USF Tampa Graduate Theses and Dissertations

Goal 6 of the United Nations Development Program’s new Sustainable Development Goals aims to ensure availability of clean water and sustainable management practices to all by the year 2030. Peace Corps Panama partners with communities in order to help provide sustainable water solutions to communities in need. Water, Sanitation, and Hygiene (WASH) Volunteers spend at least two years living in a community to identify and implement solutions to water problems and train local water committees on how to maintain their improved systems. A common solution for unequal distribution of flow in the distribution network of a gravity flow water system …

Development Of A Decentralized And Off-Grid Anaerobic Membrane Bioreactor (Anmbr) For Urban Sanitation In Developing Countries, Robert Alonso Bair

USF Tampa Graduate Theses and Dissertations

Urbanization has led to rapid and uncontrolled growth of informal housing settlements in many developing countries. As most slum growth is unplanned, these areas tend to lack basic infrastructure including sanitation. The high user rates, lack of water and electricity infrastructure, space limitations, and scant financial resources make sanitation provision a major challenge in slums. As most decentralized sanitation technologies fail when applied in these environments, better technologies need to be developed that cater to the specific needs of slum dwellers. One promising technology, the membrane bioreactor (MBR) is routinely used in developed countries when a compact and resilient treatment …

Automated Device To Measure Slurry Properties In Drilled Shafts, Miles Patrick Mullins

USF Tampa Graduate Theses and Dissertations

Slurry is the fluid within a drilled excavation that is introduced when an excavation is deeper than the water table or where additional stability is needed for loose sandy dry soils. Although construction practices vary greatly throughout the country and the world, slurry levels should be maintained above the existing ground water level by a suitable margin. The most widely used slurry type is mineral slurry formed by mixing dry clay powder with water; either bentonite or attapulgite powder may be used (attapulgite being used in saline water conditions). Regardless of whether the slurry material is mineral, polymer or natural, …

Computational Code For Optimization Of Thermal Treatment Of Fine Grained Soils As A Method Of Expediting Their Load Induced Consolidation, Radhavi Abeysiridara Samarakoon

USF Tampa Graduate Theses and Dissertations

Construction in soft soils has been a challenging task for engineers due to the excessive time taken for dissipation of construction induced pore water pressure and the ensuing postconstruction settlement. Use of vertical drains has proven to be an effective and economical method for soft ground improvement and hence extensive research has been carried out to further improve its efficiency. Effect of temperature on radial consolidation is one aspect of such research among many others that have been pursued.

Elevated temperature certainly has a pronounced effect on the hydraulic conductivity due to the reduction it causes in the viscosity of …

A Life Cycle Assessment Of A Uranium Mine In Namibia, Janine Lambert

USF Tampa Graduate Theses and Dissertations

Uranium mining and nuclear power is a controversial topic as of late, especially in light of the recent Fukushima event. Although the actual use of nuclear fuel has minimal environmental impact, its issues come at the very beginning and end of the fuel’s life cycle in both the mining and fuel disposal process. This paper focuses on a life cycle analysis (LCA) of uranium mine in the desert nation of Namibia in Southern Africa. The goal of this LCA is to evaluate the environmental effects of uranium mining. The LCA focuses on water and energy embodiment such that they can …

Impact Of Sludge Layer Geometry On The Hydraulic Performance Of A Waste Stabilization Pond, Faissal Romaric Ouedraogo

USF Tampa Graduate Theses and Dissertations

Improving the hydraulic performance of waste stabilization ponds (WSPs) is an important management strategy to not only ensure protection of public health and the environment, but also to maximize the potential reuse of valuable resources found in the treated effluent. To reuse effluent from WSPs, a better understanding of the factors that impact the hydraulic performance of the system is needed. One major factor determining the hydraulic performance of a WSP is sludge accumulation, which alters the volume of the pond.

In this study, computational fluid dynamics (CFD) analysis was applied to investigate the impact of sludge layer geometry on …

Interaction Of Cementitious Systems With Chemical Admixtures, Natallia Shanahan

USF Tampa Graduate Theses and Dissertations

The use of supplementary cementitious materials (SCMs) in commercial construction have been increasing over the last several decades as climate change and sustainability has been gaining global attention. Incorporation of SCMs into concrete mixtures provides several environmental benefits. Since most SCMs are waste by-products of other industries, their use in concrete reduces waste disposal. Additionally, cements substitution with SCMs reduces the carbon footprint of the construction industry. Cement production generates large amounts of CO₂ emissions; the use of SCMs reduces the amount of cement in a concrete mixture thereby reducing emissions from its production.

In addition to SCMs, modern …

Sustainability At U.S. Urban Water Utilities: A Framework To Assess Key Attributes, Matthew Paul Ries

USF Tampa Graduate Theses and Dissertations

Urban water utilities in the United States face challenges due to a combination of external drivers. These include urbanization and population growth, which are stressing a system of aging infrastructure. Compliance with increasing regulations is also a challenge in a fiscally-constrained economic environment. A changing climate threatens infrastructure and past assumptions for water supply and quality. Urban utilities provide clean water and sanitation services to over 80% of the country’s population and its industrial centers. Therefore, the sustainability of these water utilities are crucial to the country’s and the public’s well-being.

New operating models are emerging for a “utility of …

Sizing An Anaerobic Digester In A Rural Developing World Community: Does Household Fuel Demand Match Greenhouse Gas Production?, Ronald Keelan Greenwade

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion is the process by which organic carbon is converted into biogas in the form of carbon dioxide (CO₂) and methane (CH₄). Both of these products are greenhouse gases that contribute to global warming. Therefore if anaerobic reactors are improperly maintained and biogas is leaked or intentionally released into the atmosphere because biogas production exceeds household demand, these reactors may become generators of greenhouse gas emissions instead of sustainable energy producers. The objective of this research was to develop a framework to assess if the demand for biogas by a rural adopter of an anaerobic …

Application Of Spatial And Descriptive Analysis Methods To Determine Relationship Between Hardware Subsidies And The Sanitation Marketplace, Danielle Devuyst

USF Tampa Graduate Theses and Dissertations

Sanitation marketing is an emerging approach of strengthening the local private sector to implement scalable and sustainable improved sanitation coverage in developing countries, specifically among the poor. It encourages the enhancement of sanitation market supply and demand by developing distribution infrastructure and stimulating consumer interest. Unlike interventions that provide hardware subsidies to initiate sanitation demand, financial support for sanitation marketing is used exclusively for the research and development of the market; this encourages the private sector to become independent and self-sufficient. Qualitative data suggests that while sanitation marketing projects have been successful at implementing replicable and sustainable sanitation coverage, they …

In-Situ Testing Of Uretek's Injectable BarrierSm As A Mechanism For Groundwater Control, Jeremy Hess

USF Tampa Graduate Theses and Dissertations

Construction projects involving the installation or repair of subsurface structures or utilities often require dewatering to induce a temporary lowering of the local groundwater elevation to facilitate construction. In the event that a known contaminant plume is present in an adjacent area, this dewatering may inadvertently draw the contaminant into the previously uncontaminated work area. Uretek Holdings, Inc. has developed its Injectable Barrier^SM to be installed prior to dewatering exercises to provide a groundwater cut-off by reducing the potential movement of groundwater due to the hydraulic gradient induced by dewatering. A benefit of Injectable Barrier^SM as compared to …

Adoption Of The Sawyer Water Filter In Peru, Stephanie D. Paredes

USF Tampa Graduate Theses and Dissertations

In Peru, lack of water, sanitation, and hygiene (WASH) results in 6,600 deaths per year that represents approximately 3.9% of total deaths. Three thousand and nine hundred of these deaths were due to diarrheal diseases (Prüss-Üstün et al., 2008). Systematic reviews suggest that interventions to improve microbial quality of drinking water are successful in reducing diarrheal diseases (Fewtrell et al., 2005; Clasen et al., 2007; Fry et al., 2013). Interventions for household water treatment and safe storage to ensure safe drinking water reduce diarrhea by 31-52% (WHO/UNICEF, 2013).

The SAWYER PointONE filter, a portable and adaptable membrane filtration device as …

Water Metering In Rural, Piped, Community-Managed Water Systems In The Developing World, Simona Platukyte

USF Tampa Graduate Theses and Dissertations

In the early 1990s, the United Nations (UN) recognized water as a finite resource to the entire ecosystem with an economic value that should be developed and managed based on the participatory approach using the Integrated Water Resource Management (IWRM) strategy. Many studies on water management practices have thus emerged in the developing world. Of particular interest to this work is the management of water through metering, price-setting, and rule enforcement in the rural setting in piped, community-owned water systems. There is very little published information regarding metering, enforcement experiments, and experiences in these systems. This is because metering and …

Experimental Studies Of Simultaneous Nitrification Denitrification And Phosphorus Removal At Falkenburg Advanced Wastewater Treatment Plant, Ann Elizabeth Sager

USF Tampa Graduate Theses and Dissertations

The discharge of point- and non-point source pollutants into surface waters resulting from industrial and/or municipal activities is a major focus of environmental regulation in the United States. As a result, the National Pollutant Discharge Elimination System (NPDES) permit program was established in 1972 in an effort to regulate discharges from industrial or municipal sources, including wastewater treatment plants (WWTP). To further protect Florida water quality, in 1978, State legislation enacted the Grizzle-Figg Act for Tampa Bay, which requires advanced wastewater treatment for any discharge into sensitive water bodies. A common use of wastewater effluent in the Tampa Bay area …

Cement Heat Of Hydration And Thermal Control, Ahmadreza Sedaghat

USF Tampa Graduate Theses and Dissertations

Heat of hydration is a property of Portland cement and a direct result of the chemical reaction between cement and water. The amount of heat released is dependent upon the cement mineralogical composition, curing temperature, water to cement ratio, and cement fineness. High temperature resulting from heat of hydration (thereon referred to as HOH) of cement can affect the hydration process, and consequently the kinetics of development of the mechanical properties of concrete. One of the main reasons triggering the interest in HOH of cement is its implication in thermal cracking of concrete. The high temperature gradient between the inner …

Modeling The Extent Of Virus Removal In Waste Stabilization Ponds To Support Reuse Of Wastewater, Kelly James Vannoy

USF Tampa Graduate Theses and Dissertations

Waste stabilization ponds (WSPs) are one of the most prevalent types of domestic wastewater treatment technologies employed worldwide, and global stressors such as urbanization, population growth, climate change, and water scarcity have increased the demand for reusing treated wastewater. The safe reuse of treated wastewater in agriculture can ease water scarcity, aid in food production, and reduce environmental degradation from the discharge of wastewater effluent to surface waters. The ability to predict virus concentrations in wastewater effluent is an important criterion for determining whether wastewater is suitable for discharge to the environment or for reuse in agriculture. However, many uncertainties …

Full Scale Evaluation Of Organic Soil Mixing, Kelly Costello

USF Tampa Graduate Theses and Dissertations

Soil mixing is a procedure that has proven to be effective for loose or soft compressible soils. The method stabilizes the soil in-place using specialized augers, tillers, or paddles that inject grout or dry cementitious powders as part of the mixing process. The Federal Highway Administration design manual for soil mixing helps to estimate the required amount of cementitious binder to produce a target design strength. However, it is biased towards inorganic soils and only mentions caution when confronting organic soils which usually come with a high water table, moisture content and void volume.

The Swedish Deep Stabilization Research Centre …

Modeling Food Security, Energy, And Climate And Cultural Impacts Of A Process: The Case Study Of Shea Butter In Sub-Saharan Africa, Colleen Claire Naughton

USF Tampa Graduate Theses and Dissertations

Millions of people in the world, particularly women and people in sub-Saharan Africa, suffer from hunger and poverty. Three of the major 2015-2030 United Nation’s Sustainable Development Goals (SDGs) aim to eliminate hunger through food security and sustainable agriculture, eradicate poverty, and achieve gender equality through women’s empowerment. Shea trees and their associated fruit and butter can play a major role in each of these three SDGs for women and their families throughout sub-Saharan Africa. Shea trees are located over a wide expanse stretching more than 5,000 kilometers across over eighteen countries in sub-Saharan Africa. These trees produce fruit that …