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Efficient Management Of Nitrogen And Phosphorus At Centralized Water Reclamation Facilities, Helene Kassouf

USF Tampa Graduate Theses and Dissertations

A variety of process configurations are employed at municipal water reclamation facilities (WRFs), such as 5-stage Bardenpho, oxidation ditch, modified Ludzack-Ettinger (MLE) process, and sidestream recycle. However, all of these configurations face certain challenges in achieving optimum treatment of nitrogen and phosphorus. In this dissertation, the driving objectives were to: (1) quantitatively assess the fate of nitrogen and phosphorus (mass fluxes) at a treatment facility that employs biological nutrient removal, aerobic digestion, and sidestream recycle, (2) evaluate the performance of a microbial fuel cell (MFC) as a technology to remove nitrogen from sidestreams at a treatment plant that employs that …

Pressure Retarded Osmosis: A Potential Technology For Seawater Desalination Energy Recovery And Concentrate Management, Joshua Benjamin

USF Tampa Graduate Theses and Dissertations

Currently, a significant challenge with reverse osmosis-based desalination is reducing the energy consumption and environmental impacts of the process. This project analyzed the viability of using pressure-retarded osmosis (PRO) for energy recovery in seawater desalination facilities using brine concentrate (the draw solution) and other water sources (the feed solution) such as wastewater effluent. The primary goal of this project is to decrease the cost and overall energy consumption of seawater desalination through PRO-based energy recovery. Process modeling, statistical and sensitivity analysis, energy and cost analysis, geospatial and GIS analysis, laboratory-scale testing, water quality analysis, SEM-EDS microscopy, computational fluid dynamics (CFD), …

Shortcut Nitrogen Removal In Photo-Sequencing Batch Reactor, Experiments, Dynamic Model And Full-Scale Design, Sahand Iman Shayan

USF Tampa Graduate Theses and Dissertations

Nitrogen is one of the essential elements for life; however, inefficient use of nitrogen creates major environmental problems. Nitrogen-rich streams from urban areas, farms, and wastewater treatment plants (WWTPs) lead to surface and groundwater contamination, resulting in eutrophication, hypoxia, and notable environmental, public health and economic damage. Ammonia is a form of nitrogen that can be created during industrial or biological nitrogen fixation or decomposition of biomass. Anaerobic digesters (ADs) in WWTP generate biogas from collected sludge from primary and secondary clarifiers to achieve energy recovery in the plant. However, sidestream effluent from dewatering AD sludge contains high concentrations of …

A System Architecture For Water Distribution Networks, Noha Abdel-Mottaleb

USF Tampa Graduate Theses and Dissertations

This dissertation examines structure-function relationships of water distribution networks (WDNs), with focus on improving the decision-making process for water utilities. WDNs are lifeline infrastructure systems, necessary for the functioning of cities. Yet water utilities around the world struggle with emerging challenges that include but are not limited to aging infrastructure components, limited budgets, increased interdependencies between infrastructure systems, increased rates of urbanization, and increasing extreme weather conditions. This is why enhancing the performance of WDNs is a priority for water utilities around the world. This research begins to delineate a system architecture for WDNs and evaluates the use of various …

Driver Perceptions On Taxi-Sharing And Dynamic Pricing In Taxi Services: Evidence From Athens, Greece., Christina Milioti, Konstantinos Kepaptsoglou, Konstantinos Kouretas, Eleni Vlahogianni

Journal of Public Transportation

The taxi industry has changed dramatically during the last decade, as ride-sourcing applications, ride-sharing and alternative pricing schemes have emerged, either as complementing or competitive services and strategies. After some years of familiarity with such trends, it is interesting to explore where the taxi industry stands with respect to possible service innovations. This paper explores behavioral patterns of drivers, focusing on issues such as their preferred way of conducting business, and their views on introducing taxi-sharing and dynamic pricing. Data collected from a face-to-face questionnaire survey in Athens, Greece are exploited, and appropriate econometric models are developed for the purposes …

Community Assessment Of Water Perceptions And Household Point-Of-Use Treatment Methods In Madagascar, Isabella Rose Silverman

USF Tampa Graduate Theses and Dissertations

One in four people around the world do not have access to safe drinking water, which means that two billion people globally lack access. In high-income countries, 0.02% of yearly deaths are attributed to unsafe water sources; however, an alarming 10.6% of deaths occur in Madagascar, for the same reason.

To achieve Sustainable Development Goal 6: Ensure access to water and sanitation for all, a collaboration between public health and engineering is critical. Within the public health sector, social marketing is commonly utilized to address a problem by using commercial marketing principles to change behavior for the good of society. …

Sanitation Marketing In Uganda: The Impact Of Gender On Participation And Outcomes, Elizabeth Vicario

USF Tampa Graduate Theses and Dissertations

Uganda aims to reach universal access to basic sanitation under Sustainable Development Goal #6, but achieving this target by 2030 would require doubling the annual rate of progress. Women are disproportionately affected by poor sanitation due to their health needs and risk of facing violence, but they have historically been excluded from sanitation planning. Low household demand and poor service delivery have stalled progress in Uganda. Market-based sanitation (MBS) is a novel method of developing a sanitation market through stimulating demand and supporting a competitive atmosphere for product and service providers. This research studies the sanitation marketing activities implemented by …

Laboratory Examination Of Lead Weights Harvested From Pitcher Pumps In Eastern Madagascar, Madelyn Wilson

USF Tampa Graduate Theses and Dissertations

Previous sampling campaigns in Tamatave, Madagascar, conducted by the University of South Florida (USF) have identified lead contamination in drinking water sourced from self-supply pitcher pumps. The pitcher pump piston and foot valves were identified as the primary source of lead contamination since they are often manufactured from recycled lead acid batteries. The previous field sampling technique consisted of collecting an aliquot of a 10-15-liter composite sample from the pitcher pump for dissolved lead analysis; however, this technique (1) neglects the contribution of particulate lead, (2) does not properly account for the effects of water stagnation inside the pitcher pump …

Use Of Biochar And Zeolite For Landfill Leachate Treatment: Experimental Studies And Reuse Potential Assessment, Thanh Thieu Lam

USF Tampa Graduate Theses and Dissertations

Leachate is a highly colored liquid waste product of landfills that contains high concentrations of ammonia nitrogen (NH4+-N), refractory organic matter, and heavy metals. It is commonly disposed to local publicly owned treatment works (POTWs). With these potent characteristics, it interferes with the physical, biological, and chemical treatment processes within POTWs. Sequencing batch biofilm reactors (SBBR) and hybrid subsurface flow constructed wetlands (CW) have been used in the past to treat landfill leachate, but their design and performance can still be optimized. Addition of low-cost adsorbent materials to SBBRs and CWs, such as biochar and zeolite, have the potential to …

Using Fuzzy Clustering Of User Perception To Determine The Number Of Level-Of-Service Categories For Bus Rapid Transit, Yueying Huo, Jinhua Zhao, Xiaojuan Li, Chen Guo

Journal of Public Transportation

The concept of level of service (LOS) is meant to reflect user perception of the quality of service provided by a transportation facility or service. Although the LOS of bus rapid transit (BRT) has received considerable attention, the number of levels of service of BRT that a user can perceive still remains unclear. Therefore, in this paper, we address this issue using fuzzy clustering of user perception. User perception is defined as a six-dimension vector of the perceived arrival time, perceived waiting time, bus speed perception, passenger load perception, perceived departure time, and overall perception. A smartphone-based transit travel survey …

Minimum Cut-Sets For The Identification Of Critical Water Distribution Network Segments, Xiliang Mao

USF Tampa Graduate Theses and Dissertations

To ensure adequate performance of water distribution networks, utilities must identify critical segments within the network that will adversely affect users when failures occur. Currently, time consuming hydraulic simulations are used for such criticality analyses. A method can be of great benefit for utilities if it can easily evaluate the criticality of water distribution network segments. This research applies topology-based methods for the preliminary screening of critical segments. This study evaluated the connectivity between sources and each demand segment in water distribution networks using minimum cut-sets. Through topological analysis, the minimum cut -set between the source node and each demand …

Effects Of Nitrate On Arsenic Mobilization During Aquifer Storage And Recovery, Hania Hawasli

USF Tampa Graduate Theses and Dissertations

Aquifer storage and recovery technology is used to sustain water resources and to prevent saltwater intrusion. The injected water can come from various resources, including treated wastewater. In pilot ASR studies in the Tampa Bay region, researchers found high As concentrations in the recovered water from the oxidation of the arsenopyrite that is embedded in the aquifers. The presence of dissolved O2 in the injected water is a major factor in the arsenopyrite oxidation during ASR, however the effects of NO3- on the arsenopyrite has not been studied yet. This is an important knowledge gap because injected water may contain …

Understanding Transantiago Users’ Motivations For Paying Or Evading Payment Of Bus Fares, Carolina Busco, Felipe González, Yamil Jaqueih, Felipe Jiménez, Borja Alonso

Journal of Public Transportation

Transantiago, the public transport system implemented in Santiago, Chile, remains a controversial subject of public debate due to constantly increasing fare evasion rates throughout its decade-long existence. The

Transantiago, the public transport system implemented in Santiago, Chile, remains a controversial subject of public debate due to constantly increasing fare evasion rates throughout its decade-long existence. The research question under consideration in this paper is as follows: What motivates individuals to evade or pay bus fares? To answer this question, we developed a multidisciplinary study that combined relevant engineering expertise with a sociological perspective and combined quantitative analyses with qualitative methodologies …

People-Focused And Near-Term Public Transit Performance Analysis, Alex Karner

Journal of Public Transportation

Public transit ridership forecasts have long played a role in understanding the potential success of a policy or investment, but their limitations have led researchers and practitioners to identify other performance analysis approaches. Accessibility, or the ease of reaching opportunities, has become very popular and widely used for this purpose. But commonly used accessibility measures also embody weaknesses that are seldom acknowledged; these limit their utility for truly understanding the benefits of transit investments. In this paper, we identify the pros and cons of these competing approaches and offer a third strategy. Specifically, we describe how revealed travel behavior data, …

Computational Fluid Dynamics (Cfd) Analysis Of The Hydraulic Performance And Bio-Kinetics In A Full-Scale Oxidation Ditch, Kiesha C. Pierre

USF Tampa Graduate Theses and Dissertations

An oxidation ditch is a biological wastewater treatment unit process where microorganisms are utilized to transform organic matter, and nitrogen from wastewater to meet the desirable effluent concentrations. Mechanical aerators are part of these biological reactors facilitating oxygen transfer for the aerobic microorganisms, while agitating and circulating the phase constituents within the ditch. Modeling the performance of an oxidation ditch involves combining hydrodynamics, oxygen mass transfer, and bio-kinetics and is one of the grand challenges that is of paramount importance in optimization of design and operations of these facilities in an energy efficient way while meeting the targeted effluent concentrations. …

Influence Of Coating Defects Within The Lock Seams On The Corrosion Performance Of Aluminized Steel Drainage Pipes, Mohammed Al Yaarubi

USF Tampa Graduate Theses and Dissertations

The electrochemical behavior of aluminized steel is investigated to determine the corrosion performance of coating deficiencies generated within the lock seams during the fabrication of aluminized steel corrugated pipe. Electrochemical techniques and visual and profilometric analysis are used to assess the ability of the aluminum and zinc coating to provide sufficient galvanic protection to the underlying steel in the presence of a crevice. Also, Crevice coupons and lock-seam samples were used in this investigation in different environmental conditions simulating natural water conditions to relate the corrosion rate with the level of protection that the coating will provide. In addition, a …

Corrosion Propagation Of Stainless Steel Reinforced Concrete, Nelly Sofía Orozco Martínez

USF Tampa Graduate Theses and Dissertations

Structural durability is a growing concern in global infrastructure. The infrastructure report card released by the American Society of Civil Engineers (ASCE) indicates that approximately 9.1% of the total bridges in the United States were structurally deficient in 2016. In addition, it suggests that about 40% of the total bridges in the country are now 50 years or older. This issue becomes even more critical in structures exposed to aggressive environments such as marine structures. Thus, federal and regional efforts are now being directed towards infrastructural durability improvement to improve the long-term cost-efficiency of civil infrastructure.

Corrosion prevention strategies may …

Development Of A Numerical Process Model For Adsorbent-Amended Constructed Wetlands, Lillian Mulligan

USF Tampa Graduate Theses and Dissertations

There is a need for alternative methods for municipal landfill leachate treatment as the high concentrations of pollutants in leachate interfere with processes at publicly owned treatment works (POTWs). Constructed wetlands (CWs) have been shown to be a sustainable alternative with good removal efficiencies for chemical oxygen demand (COD) and ammonia nitrogen (NH4+). The addition of an adsorbent media, such as zeolite and biochar, to CWs to further enhance removal efficiencies has been investigated in recent years. However, the long-term effects of zeolite and biochar addition to CWs is not well known. A model could be a useful tool to …

Corrosion Durability Service Life Of Calcium Silicate-Based Reinforced Concrete, Carolina Páez Jiménez

USF Tampa Graduate Theses and Dissertations

Corrosion of reinforcing steel is a major area of study for assessing durability of reinforced concrete infrastructure. Conventional concrete infrastructure designs use ordinary Portland cement (OPC) as the primary cementitious material. However, the world's current challenge to achieve sustainable development requires the cement industry to reduce its environmental impact, as it is responsible for 8% of the anthropogenic CO2 emissions. Hence, a new type of cement has been developed. This novel calcium silicate cement (CSC) reduces the carbon dioxide emissions during its manufacturing process as compared to OPC, providing an environmentally-sound alternative for reinforced concrete fabrication.

Corrosion of steel reinforcement …

Sustainability Assessment Of A Pressure Retarded Osmosis System, Samar Al Mashrafi

USF Tampa Graduate Theses and Dissertations

Desalination has the potential to provide a stable supply of clean fresh water and meet the increasing water demands; however, this process does come with a few challenges such as high energy consumption, high energy cost, and a discharge of a highly concentrated brine. Pressure retarded osmosis (PRO) is a technology that could work as an efficient energy recovery technology for desalination since it can significantly reduce the energy consumption and dilute the brine before discharge. Studies have assessed the economic feasibility of PRO systems; however, these studies have not addressed the environmental sustainability of the systems. Thus, there is …

Leaf Cutter Ant Nest Soil Cement Stabilized Earthen Bricks: Materials And Methods For Engineering Field Applications, Faith Malay

USF Tampa Graduate Theses and Dissertations

As climate change threatens vulnerable tropical climates and development outpaces resource availability, the need for diverse construction material grows. The United Nations Sustainable Development Goals aim to reduce poverty in all forms. Diversifying construction material works toward reducing indoor air pollution, the eradication of houselessness, encouraging diversification in industry, and supporting small scale industrialization. In the Province of Bocas del Toro in Panama, there is a tenuous connection to the greater industries in the country due to location and existing infrastructure.This research presents a literature review of the historical approaches to the construction and chemistry of cement stabilized earth bricks, …

Chorine Conversion: Biological And Water Quality Impact On Activated Carbon Block Point Of Use Filters, Horace S. Jakpa

USF Tampa Graduate Theses and Dissertations

Point-of-use (POU) activated carbon (AC) filters are ubiquitous in many U.S. households. AC can reduce concentrations of lead, other heavy metals, and mitigate taste and odor issues. However, AC filters also remove residual disinfectants, thus allowing for the proliferation of microbes in the filter. In chloraminated systems, this can lead to localized, filter-induced nitrification. Most notably, high nitrite and nitrate in drinking water can cause methemoglobinemia (blue baby syndrome) in children under the age of three, raising public health concerns.

As a control measure for nitrification within distribution systems, utilities practice periodic, short-term secondary disinfectant switches from chloramine to free …

Health Risk Assessment Of Local Populations Ingesting Water With Naturally Occurring Arsenic And Fecal Related Contaminants In Lake Atitlan, Guatemala, Marisol Alvarez

USF Tampa Graduate Theses and Dissertations

Lake Atitlan, Guatemala acts as a sink for wastewater discharge and as a source of drinking water. The populations living in the lake basin are primarily indigenous with a large percentage (70%) living in poverty. Wastewater effluent entering the lake poses an immediate health risk to those using it as a drinking-water source. Additionally, the lake is surrounded by three volcanoes and the water has concentrations of naturally occurring arsenic above the recommended reference level of 10 µg/L. Arsenic is acutely poisonous at high concentrations and has carcinogenic and neurological effects when chronically exposed at low concentrations.

The goal of …

Increasing Boarding Lost Time At Regular Bus Stops During Rainy Conditions: A Case Study, Margarita Novales, Alfonso Orro, José-Benito Pérez-López, Jorge Feal, Miguel R. Bugarín

Journal of Public Transportation

Inclement weather conditions affect the behavior of travelers and transportation system operations. Understanding this influence can help improve operational planning schemes for any mode of transport, especially for buses. One of the factors that can be affected by rainfall is the time expended by a passenger from the moment a bus opens its doors until he/she boards the bus. This time is known as the boarding lost time (BLT); it was first introduced in the last edition of the Transit Capacity and Quality of Service Manual (TCQSM). TCQSM only considers the BLT for bus rapid transit (BRT) stations with more …

Modeling Bus Bunching And Anti-Bunching Control Accounting For Signal Control And Passenger Swapping Behavior, Qi Xin, Rui Fu, Shaowei Yu, Satish V. Ukkusuri, Rui Jiang

Journal of Public Transportation

The conventional bus propagation process has two main shortcomings: one is bus bunching, the other is extra energy consumption by idling at signalized intersection and unexpected speed variation along the route. To overcome these problems simultaneously, an extended bus propagation model and an anti-bunching control are proposed. To extend the time-based bus propagation model, we employ finite state machine and intelligent driver model to establish a spatial-temporal based bus propagation model accounting for bus dynamic motion and passenger swapping behavior between bunching buses. To mitigate bus bunching and improve bus fuel economy in a cyber-traffic environment, an anticipated average speed …

Assessment Of The Environmental Sustainability Of A Small Water Production Facility In Madagascar, Jesal Patel

USF Tampa Graduate Theses and Dissertations

Nearly 2.2 billion people around the globe struggle with access to safely managed drinking water (WHO/UNICEF, 2019), however, there have been certain initiatives taken, particularly by means of small water production facilities for enhancing access to basic drinking water services in rural areas. The water production facility, specifically located in the low- and middle-income countries, usually encounter operational difficulties as a result of limited availability of resources and are required to depend on other resourceful countries for goods and services. Although, with limited research done for assessing the environmental sustainability of water facilities in low- and middle-income countries, numerous data …

Longitudinal Trajectory Tracking Analysis For Autonomous Electric Vehicles Based On Pid Control, Hossein Amiri

USF Tampa Graduate Theses and Dissertations

The implementation of autonomous vehicles has huge potential for revolutionizing transportation as we currently know it. All use cases of autonomous vehicles require the vehicle to travel on a pre-specified path. Accurate tracking of this defined trajectory is a crucial aspect of the implementation of autonomous vehicles; a controller system is required to translate this pre- defined trajectory in the form of the throttle, brake, and steering inputs. This project covers the application of a Proportional-Integral-Derivative (PID) controller to achieve longitudinal trajectory tracking of autonomous electric vehicles with stability and accuracy in the CARLA autonomous driving simulation platform. The implemented …

Passive Nitrifying Biofilters For Onsite Treatment Of Saline Domestic Wastewater, Daniel Arnulfo Delgado

USF Tampa Graduate Theses and Dissertations

The infrastructure to support the growing world population has polluted many water bodies with nitrogen from urban and agricultural runoff and failing wastewater systems, such as improperly sited and maintained septic systems. Septic systems present a low energy and maintenance option to treat domestic wastewater and is a treatment option that can be done far from a centralized grid. This further reduces cost, maintenance, and energy as it reduces the need to build and maintaining sewage piping and the infrastructure to move the water longer distances. However, these systems tend to fail when their upkeep is left to homeowners that …

Understanding The Leaching Mechanism For Lead (Pb) Found In Components Of Locally Manufactured Handpumps In Eastern Madagascar, Nidhi Shah

USF Tampa Graduate Theses and Dissertations

This research sought to determine the lead leaching mechanism impacted by an inorganic scale observed from lead valve weights of the pitcher pump systems used in Tamatave, Madagascar. Based on previous research, these valve weights are considered to be a major source for high lead levels in pump water consumed by the residents. As a part of the study, Raman Spectroscopy, X-ray Fluorescence Spectroscopy (XRF) and Energy Dispersive Spectroscopy with Scanning Electron Microscope (SEM-EDS) were performed to address the objectives of this research. The pump component samples for the analysis were selected based on the amount and visual characteristics of …

Feasibility Of Epoxy Bond Enhancement On High-Strength Concrete, Amanda A. Lewis

USF Tampa Graduate Theses and Dissertations

While fiber-reinforced polymer materials have many applications in various industries,when used structurally, many cases, such as flexural and shear strengthening, are considered bond critical. Interfacial bond quality between a fiber-reinforced polymer system and the substrate is dependent on two mechanisms: chemical bonding and mechanical interlock, with mechanical interlock having the greater effect on bond quality. Mechanical interlock describes the type of bond that occurs as a result of surface roughness and substrate porosity and can be significantly affected by surface preparation methods and surface moisture. This study aims to explore the possibility of enhancing bond quality between carbon-fiberreinforced polymers and …