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Title: Degradation of Perfluorooctanoic Acid by a Non-Thermal Plasma Reactor and Bio-Reactors.
Creator: Farahani, Meysam, Tang, Youneng, Locke, Bruce R., Clark, Clayton J., Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: Perfluorooctanoic acid (PFOA) is persistent in environment due to its stable structure. It is also toxic to animals and human. The objective of this research is to remove PFOA with a non-thermal plasma reactor, anaerobic and aerobic bio-reactors, and their combination. Mineralization and defluorination (i.e., fluoride production) occurred in the plasma reactor. Neither PFOA removal nor fluoride production was observed in the bioreactors. In the plasma reactor with Argon as the carrier gas, 20...
Show morePerfluorooctanoic acid (PFOA) is persistent in environment due to its stable structure. It is also toxic to animals and human. The objective of this research is to remove PFOA with a non-thermal plasma reactor, anaerobic and aerobic bio-reactors, and their combination. Mineralization and defluorination (i.e., fluoride production) occurred in the plasma reactor. Neither PFOA removal nor fluoride production was observed in the bioreactors. In the plasma reactor with Argon as the carrier gas, 20 µM of PFOA in deionized (DI) water was removed to 4.22 and 4.04 µM, respectively, when the hydraulic retention time (HRT) was 0.21 s and 0.15 s, respectively. When the carrier gas was changed to Helium, PFOA was removed to 3.85 µM and 3.77 µM, respectively. Therefore, the carrier gas and HRT did not have significant effect on PFOA degradation. However, the carrier gas and HRT strongly affected the defluorination rate: 11% (for HRT = 0.21 s) and 6.5% (for HRT = 0.15) when Argon was the carrier gas, and 22% (for HRT = 0.21 s) and 8.6% (for HRT = 0.15 s) when Helium was the carrier gas. Consequently, a higher energy yield was achieved with Helium as the carrier gas (maximum of 11.3×10-11 mole F- production/J) than with Argon as the carrier gas (maximum of 6.43×10-11 mole F- production/J). Perfluoroheptanoic acid (PFHpA) and perfluorohexanoic acid (PFHxA) were observed in the effluent of the non-thermal plasma reactor by using liquid chromatography-tandem mass spectrometry (LC/MS/MS). The intermediates production rate was higher when argon was the carrier gas compared with Helium, probably because the degradation mechanisms are different for PFOA and their intermediates.
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Date Issued: 2019
Identifier: 2019_Spring_Farahani_fsu_0071N_15034
Format: Thesis

Title: Enhancement of Nitrogen Use Efficiency and Mitigation of Nitrous Oxide Emission in Agricultural Fields.
Creator: Li, Simeng, Chen, Gang, Sang, Qing-Xiang, Clark, Clayton J., Tang, Youneng, Florida State University, FAMU-FSU College of Engineering (Tallahassee, Fla.), Department of Civil...
Show moreLi, Simeng, Chen, Gang, Sang, Qing-Xiang, Clark, Clayton J., Tang, Youneng, Florida State University, FAMU-FSU College of Engineering (Tallahassee, Fla.), Department of Civil and Environmental Engineering
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Abstract/Description: Recent intensification of agriculture in face of the continuously increasing food demand has caused many environmental and socioeconomic problems. Excessive use of nitrogen (N) fertilizers is prevalent on many farms today. However, a large proportion of the N applied to agricultural soil contributes very little to crop production. Instead, a considerable amount of N is lost via leaching into groundwater, via runoff into surface water, and via nitrous oxide (N2O) emission into the atmosphere....
Show moreRecent intensification of agriculture in face of the continuously increasing food demand has caused many environmental and socioeconomic problems. Excessive use of nitrogen (N) fertilizers is prevalent on many farms today. However, a large proportion of the N applied to agricultural soil contributes very little to crop production. Instead, a considerable amount of N is lost via leaching into groundwater, via runoff into surface water, and via nitrous oxide (N2O) emission into the atmosphere. As a result, the ecosystem is negatively impacted. Sustainable N management should aim at supplying sufficient N for optimum crop growth and development, while keeping losses to the environment to a minimum. Towards this goal, it is essential to enhance N retention and at the same time mitigate N2O emission in agricultural soil. Being the leader of one USDA project, I investigated the effects of different N management approaches that are based on the use of biochar, dicyandiamide (nitrification inhibitor) and polyacrylamide (superabsorbent hydrogel) in agricultural soils. It was found that a significantly higher amount of ammonium (NH4+) could be retained in the biochar-amended soil, comparing to the control soil. However, the retention of other ionic forms of N, such as nitrite (NO2-) and nitrate (NO3-), was barely improved. In fertilized soil, nitrification is a common process that transforms NH4+ into NO2- and eventually NO3-. To limit this transformation, the effects of one of the most commonly used nitrification inhibitor, i.e., dicyandiamide (DCD), was studied in combination with biochar. Based on the experimental data, mathematical models were developed to estimate the rate of nitrification impacted by the inhibition of persistently degrading DCD. It was discovered that the presence of biochar accelerated the biodegradation of both DCD and NH4+, but effectively reduced the spatial separation between the two. Depending on the soil properties and environmental conditions, the combined use of DCD and biochar can have versatile effects on nitrification inhibition. Also, considering the great amount of field data reported in the literature, statistical methods such as data synthesis and meta-analysis were also exploited to excavate the insightful information on the effectiveness of different soil amendments (e.g., biochar) in terms of N retention, crop production and N2O emission. Lastly, the recalcitrance of biochar, which is directly related to biochar's soil carbon sequestration potential, was also discussed. In order to quantify and compare the soil carbon sequestration potential of biochar produced from different conditions and feedstock types, a carbon-based recalcitrance index was developed using a state-of-the-art thermochemical technique.
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Date Issued: 2019
Identifier: 2019_Summer_Li_fsu_0071E_15255
Format: Thesis

Title: Modeling Biofilm on Reactive Surface.
Creator: Wang, Boya, Tang, Youneng, Ordóñez, Juan Carlos, Chen, Gang, Huang, Wenrui, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental...
Show moreWang, Boya, Tang, Youneng, Ordóñez, Juan Carlos, Chen, Gang, Huang, Wenrui, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Biofilms were first used to treat wastewater in the late 19th century, and still play an important role in today’s wastewater treatment plants. Biofilm model is one of the most essential and powerful tools for studying biofilm process, understanding the mechanisms both inside the biofilm and between the biofilm and outside environment, and controlling the performance of the biofilm reactors. Usually the biofilm grows on inert and impermeable surfaces, but sometimes it develops on ‘active’...
Show moreBiofilms were first used to treat wastewater in the late 19th century, and still play an important role in today’s wastewater treatment plants. Biofilm model is one of the most essential and powerful tools for studying biofilm process, understanding the mechanisms both inside the biofilm and between the biofilm and outside environment, and controlling the performance of the biofilm reactors. Usually the biofilm grows on inert and impermeable surfaces, but sometimes it develops on ‘active’ surfaces, which makes it more challenging to simulate. This dissertation is focused on modeling biofilm on reactive surface. It also develops a method to estimate kinetic parameters of biodegradation to be used in models. Homoacetogenesis and methanogenesis, which usually occur during anaerobic trichloroethene (TCE) dechlorination, affect the removal of TCE and its daughter products. This study develops a one-dimensional, multi-species H2-based biofilm model to simulate the interactions among six solid biomass species (Dehalococcoides, Geobacter, methanogens, homoacetogens, inert biomass (IB), and extracellular polymeric substances (EPS)) and 10 dissolved chemical species (TCE, dichloroethene (DCE), vinyl chloride (VC), ethene, hydrogen (H2), methane, acetate, bicarbonate, utilization associated products (UAP), and biomass associated products (BAP)). To evaluate and parameterize the model, parameter values from the literature were input into the model to simulate conditions reported for an experiment. The biomass species distribution in the biofilm and the chemical species concentrations in the reactor effluent at steady state were generally consistent between the experiments and the model. The predicted 15-µm biofilm consisted of three layers, each dominated by a different active biomass type: homoacetogens in the layer next to the membrane, Geobacter in the biofilm surface layer (next to the water), and Dehalococcoides in-between. About two thirds of the TCE was converted to ethene and one third to VC due to the large half-maximum-rate concentration of VC. The effluent concentration of VC is far beyond the drinking-water maximum contaminant level (MCL) of 2 µg/L. To achieve complete removal of TCE, DCE, and VC, we evaluated the influence of various operating conditions like H2 pressure, biofilm detachment rate (kdet), and multiple stages. Through all the simulation results, we demonstrated that VC could be completely removed from the reactor when the H2 pressure was between 0.01 and 0.1 atm and kdet was between 1 and 3.6 cm-1day-1. We also found that a 2-stage system was more efficient than a single-stage reactor. All biofilm models use kinetic parameters of biodegradation. For microbial consortia, the traditional method for kinetic parameter estimation is based on the total biomass concentration and assumes that all the microorganisms are capable of degrading the contaminant. This work proposed an improved method that selects the responsible microbial groups and uses their concentrations for parameter estimation. We conducted batch experiments to track the change of contaminant and biomass concentrations, and used 16s rRNA sequencing to analyze the microbial community. Based on the correlation between the contaminant and microbial abundance, we then found the groups that were likely responsible for bio-degradation of the contaminant. PEST, the industry standard software package for parameter estimation and uncertainty analysis of complex environmental and other computer models, was used to estimate biodegradation parameters. By comparing to the conventional method, we found that the accuracy of this method was higher than that of the conventional method.
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Date Issued: 2019
Identifier: 2019_Fall_Wang_fsu_0071E_15625
Format: Thesis

Title: Removal and Recovery of Selenium from Agricultural Drainage Using Microbial Processes.
Creator: Zhang, Zhiming, Tang, Youneng, Ye, Ming, Clark, Clayton J., Chen, Gang, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: Selenium is a nutrient for animals and human at low concentrations, but toxic at high concentrations. Agricultural drainage is one type of water that may contain selenium at a high concentration due to seleniferous agricultural soils, which presents hazards to its surrounding biosphere. Microbes can be used to remove selenium from agricultural water by converting dissolved selenate to elemental selenium nanoparticles, which may then be removed or recovered as a valuable resource. However,...
Show moreSelenium is a nutrient for animals and human at low concentrations, but toxic at high concentrations. Agricultural drainage is one type of water that may contain selenium at a high concentration due to seleniferous agricultural soils, which presents hazards to its surrounding biosphere. Microbes can be used to remove selenium from agricultural water by converting dissolved selenate to elemental selenium nanoparticles, which may then be removed or recovered as a valuable resource. However, sulfate is ubiquitous in water systems and the analogous reactions between selenate and sulfate affect the selenate reduction and the downstream elemental selenium purification and recovery. This presents one challenge for selenium recovery. The location of elemental selenium nanoparticles produced by the bacteria is closely relevant to the following recovery, since extracellular selenium nanoparticles are much easier to be recovered than intracellular selenium. Most microbial species either produce intracellular selenium nanoparticles or simultaneously produce extracellular and intracellular selenium nanoparticles. Few species produce only extracellular selenium nanoparticles, which leads to another challenge for selenium recovery. The overall objective of this dissertation is to address the two challenges. Being able to accurately measuring various selenium species is the precondition to addressing the two challenges. Particulate selenium is usually separated from dissolved selenium by centrifugation or filtration, but the separation conditions vary widely and are inconsistent in the literature. By systematically studying the effects of the relative centrifugation force and filter pore size on the separation of particulate selenium from dissolved selenium in typical environmental samples, we found that the relative centrifugation force of ≥ 20,000 g and filter pore size ≤ 20 nm led to complete separation of particulate selenium in general. The presence of other particles and the concentration of particulate selenium affect the separating efficiency by centrifugation and thus should be considered while choosing the appropriate centrifugation condition. To address the first challenge, the effects of sulfate on selenate reduction were studied in a H2-based membrane biofilm reactor. The composition and spatial distribution of biological selenate reduction products were affected by the operating conditions. At a hydraulic retention time (HRT) of 0.28 day, selenate was biologically reduced all the way to elemental selenium nanoparticles, which were embedded in the biofilm, suspended in the effluent and precipitated at the bottom of the reactor. With the HRTs decreasing to 0.14 and 0.07 days, selenium sulfides were the dominant particulate selenium products in the effluent, suggesting that the abiotic reaction between selenite (the intermediate of biological selenate reduction) and sulfide (the product of biological sulfate reduction) also occurred. To address the second challenge, a biocathode-based bioelectrochemical reactor was used to eliminate the need for separating intracellular selenium from biomass. The continuous-flow bioelectrochemical reactor removed > 99.6% of the selenate at a selenate surface loading rate of 330 mg Se/m2-day, which was higher than that in most of the conventional biological reactors. The inoculum was a microbial consortium containing both intracellular and extracellular selenium-producing bacteria, but only extracellular selenium nanoparticles were observed when the biocathode was imaged by a transmission electron microscope. To understand the extracellular selenium-producing mechanisms on the biocathodes, 16S rRNA sequencing was used to study the microbial community. Selenate reducing bacteria Azospira oryzae, Desulfovibrio, Stenotrophomonas, and Rhodocyclaceae dominated the cathodic electrode. They were reported to produce both intracellular and extracellular selenium nanoparticles in conventional reactors, but they produced only extracellular selenium nanoparticles on the biocathode. Raman spectrometry further demonstrated the existence of significant Cytochrome c (Cyt c) on the BIOcathode, an enzyme that plays a key role in extracellular electron transfer and subsequent extracellular selenium production. This dissertation is based on and adapted from published journal papers and manuscripts that are ready to submit.
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Date Issued: 2019
Identifier: 2019_Fall_Zhang_fsu_0071E_15643
Format: Thesis

Title: Production and Modification of Biochar for Organics Removal and Soil Ammendment.
Creator: Brown, Douglas Lane, Ahmad, Hafiz, Chen, Gang, Tang, Youneng, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: The use of biochar as a soil amendment for agricultural purposes in various cultures has been around for centuries, perhaps millennia. This study seeks to advance this practice by investigating the use of engineered biochar, by chemical impregnation, as a means of optimizing the nutrient retaining properties of soil. As a potentially major source of nutrients are found in wastewater, the biochar is also checked for its viability of pre-loading said char with nutrients, by first using it as a...
Show moreThe use of biochar as a soil amendment for agricultural purposes in various cultures has been around for centuries, perhaps millennia. This study seeks to advance this practice by investigating the use of engineered biochar, by chemical impregnation, as a means of optimizing the nutrient retaining properties of soil. As a potentially major source of nutrients are found in wastewater, the biochar is also checked for its viability of pre-loading said char with nutrients, by first using it as a means to clean wastewater. First biochar (BC) is used to produce activated carbon (AC) and comparisons are made between the BC and AC in their ability to remove organics from wastewater, then the biochar is chemically modified with three chemicals, Ferrous sulfate Heptahydrate (Copperas), Calcium Chloride (Ice Bite), and Aluminum Potassium Sulfate Dodecahydrate (Alum), and tested for nutrient (orthophosphate and nitrate) sorption. The biochar failed in its unaltered form of removing organics (COD) from wastewater, actually adding COD into the solution. Only when the char was turned into activated carbon did it express the ability to remove COD. The chemically modified chars showed promise in their ability to adsorb nutrients (phosphate and nitrate) from solution (wastewater), as well as enhance the retention of said nutrients (particularly phosphate) within a sandy soil. The biochar amendments also significantly increased the water holding capacity of the sandy soil, regardless of BC type, by no less than 10%.
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Date Issued: 2018
Identifier: 2018_Su_Brown_fsu_0071N_14794
Format: Thesis

Title: Biological Reduction of Selenate and Recovery of Elemental Selenium from Wastewater in a Continuous-Flow System.
Creator: Adedeji, Itunu Comfort, Tang, Youneng, Chen, Gang, Clark, Clayton J., Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: The biological degradation of selenate to elemental selenium and recovery of valuable selenium nanoparticles has been extensively studied and reported by researchers throughout literature. The major challenges in degradation and recovery processes are the reduction of high concentration of selenium oxyanions and effective separation of bacterial cells and sludge from these economically beneficial elemental selenium nanoparticles. This study seeks to investigate the efficacy of a novel...
Show moreThe biological degradation of selenate to elemental selenium and recovery of valuable selenium nanoparticles has been extensively studied and reported by researchers throughout literature. The major challenges in degradation and recovery processes are the reduction of high concentration of selenium oxyanions and effective separation of bacterial cells and sludge from these economically beneficial elemental selenium nanoparticles. This study seeks to investigate the efficacy of a novel combination system comprising a biological reactor, a separating chamber and a tangential-flow ultrafiltration module (TFU). The biological reactor was investigated for its ability to reduce selenate at high loading rates. The separating chamber containing the inclined bacterium-nanoparticle separator was investigated for its ability to separate bacteria from nanoparticles. The TFU was investigated for its ability to induce a water-bacterium-nanoparticles separation even at high selenate loading rates. The reactor system worked in synergism to remove high concentration of selenate from wastewater and simultaneously recover the valuable elemental selenium nanoparticles thereby eliminating the additional use of chemicals or post-treatment operations.
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Date Issued: 2018
Identifier: 2018_Fall_Adedeji_fsu_0071N_14970
Format: Thesis

Title: Analysis of Non-Thermal Plasma Discharge Contacting Liquid Water Using Plasma Diagnostics and Computer Simulations.
Creator: Wang, Huihui, Locke, Bruce R., Alabugin, Igor V., Chella, Ravindran, Alamo, Rufina G., Florida State University, College of Engineering, Department of Chemical and Biomedical...
Show moreWang, Huihui, Locke, Bruce R., Alabugin, Igor V., Chella, Ravindran, Alamo, Rufina G., Florida State University, College of Engineering, Department of Chemical and Biomedical Engineering
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Abstract/Description: Non-thermal plasma technology, which can be used as an advanced oxidation process (AOP) for water treatment, has gained significant attention recently. A plasma discharge contacting liquid water generates strong oxidants, such as ·OH and H2O2 and, in the presence of O2, ozone (O3), which are capable of degrading or completely mineralizing many organic pollutants in waste water. The UV irradiation generated during the plasma discharge can enhance the degradation of organic compounds and kill...
Show moreNon-thermal plasma technology, which can be used as an advanced oxidation process (AOP) for water treatment, has gained significant attention recently. A plasma discharge contacting liquid water generates strong oxidants, such as ·OH and H2O2 and, in the presence of O2, ozone (O3), which are capable of degrading or completely mineralizing many organic pollutants in waste water. The UV irradiation generated during the plasma discharge can enhance the degradation of organic compounds and kill bacteria. Compared with other water treatment methods, the non-thermal plasma technology removes the pollutants completely and rapidly, and it does not introduce any new hazardous materials into the system. However, the high energy cost of non-thermal plasma technology prevents it from being commercialized. Therefore, many studies have been conducted to improve the energy efficiency of the non-thermal plasma technology. This dissertation focused on investigating the influence of operating conditions and the plasma properties on the production of H2O2 during the plasma discharge with liquid water. H2O2 is one of the most important products which indirectly indicates the concentration of ·OH generated by the plasma system. This work focused on the mechanism of H2O2 formation and analyzed the influence of plasma properties including the electron density and gas temperature on H2O2 production. The influence of operating conditions such as discharge power and carrier gases on plasma properties was also investigated. The results provide a general view of H2O2 formation in the plasma-liquid system and provide guidelines for modifying the plasma system to achieve higher efficiency. Another problem using non-thermal plasma to treat industrial waste water is that the high conductivity of waste water causes energy wastage since the current starts to flow through the liquid which generates heat. In addition, some plasma systems with low liquid conductivity tolerance cannot generate a discharge when liquid conductivity is high. Therefore, another goal of this work is to study the influence of liquid conductivity on plasma discharge with water and improve the liquid conductivity tolerance of the plasma system.
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Date Issued: 2018
Identifier: 2018_Fall_Wang_fsu_0071E_14831
Format: Thesis

Title: Optimization of Groundwater Long-Term Monitoring Network Optimization of Groundwater Long-Term Monitoring Network with Ant Colony Optimization with Ant Colony Optimization.
Creator: Liu, Xiaoli, Chen, Gang, Ye, Ming, Wang, Xiaoqiang, Hilton, Amy B. Chan, Huang, Wenrui, Tang, Youneng, Florida State University, College of Engineering, Department of Civil and...
Show moreLiu, Xiaoli, Chen, Gang, Ye, Ming, Wang, Xiaoqiang, Hilton, Amy B. Chan, Huang, Wenrui, Tang, Youneng, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Groundwater remediation is conducted in polluted sites to remove contaminants and to restore ground water quality. After remediation goals are achieved, long-term groundwater monitoring (LTM) that can span decades is required to assess the concentration of residual contaminants and to avoid the risk of human health and environment. On large remediation sites, the cost for maintaining a LTM network, collecting samples, conducting water quality lab analysis can be a significant, persistent and...
Show moreGroundwater remediation is conducted in polluted sites to remove contaminants and to restore ground water quality. After remediation goals are achieved, long-term groundwater monitoring (LTM) that can span decades is required to assess the concentration of residual contaminants and to avoid the risk of human health and environment. On large remediation sites, the cost for maintaining a LTM network, collecting samples, conducting water quality lab analysis can be a significant, persistent and growing financial burden for the private entities and government agencies who are responsible for environmental remediation projects. LTM network optimization offers an opportunity to improve the cost-effectiveness of the LTM effort while meeting data accuracy requirements. The optimization includes identifying the redundancy in the monitoring network, and recommending changes to protect against potential impacts to the public and the environment. This study develops a variant ant colony optimization (VACO) method, using ordinary kriging (OK) or inverse distance weighting (IDW) for data interpolation, to identify optimal LTM networks that minimize the cost of LTM by reducing the number of monitoring locations with minimum overall data loss. ACO is a global stochastic search method inspired by the collective problem-solving ability of a colony of ants as they search for the most efficient routes from their nests to food sources. The performance of ACO variant (VACO) developed in this study is evaluated separately in two test cases. In the first case, VACO is used to solve a simplified traveling sales person problem. In the second case, both enumeration method and VACO are employed for optimization of a synthetic long term monitoring network of 73 wells generated from a groundwater transport simulation model. The two sets of test show that the VACO performs well for optimization problems. The VACO is finally adopted for the optimization of a long term monitoring network of 30 wells in Logistic Center, Washington, with the data interpolation methods of inverse distance weighing, ordinary kriging, and modified inverse distance weighing which is developed in this study. The optimization results are analyzed and group of ideal redundant wells identified. The conclusion of this study is summarized at the end, and future work is suggested.
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Date Issued: 2017
Identifier: FSU_FALL2017_Liu_fsu_0071E_14254
Format: Thesis

Title: Removal of Powdered Activated Carbon by Cloth Tertiary Filters.
Creator: Madden, Brandon Cale, Ahmad, Hafiz, Chen, Gang, Tang, Youneng, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: Water conservation, wastewater treatment regulations, and the use of reclaimed/reuse water supplies have been on a collision course since society’s demand began outstripping the supply of fresh water. As potable water demand has risen, engineers have looked toward Waste Water Treatment Plants (WWTP) to alleviate the stress placed upon aquifers and surface water sources. Direct Potable Reuse (DPR), Indirect Potable Reuse (IPR) and Reuse/Reclaimed systems all conserve water; however, they also...
Show moreWater conservation, wastewater treatment regulations, and the use of reclaimed/reuse water supplies have been on a collision course since society’s demand began outstripping the supply of fresh water. As potable water demand has risen, engineers have looked toward Waste Water Treatment Plants (WWTP) to alleviate the stress placed upon aquifers and surface water sources. Direct Potable Reuse (DPR), Indirect Potable Reuse (IPR) and Reuse/Reclaimed systems all conserve water; however, they also unintentionally conserve pollutants. The widespread use of WWTP effluent conservation requires additional treatment options such as Activated Carbon treatment to further treat plant effluent. Powdered Activated Carbon (PAC) has shown promise as a treatment method to reduce pollutants but challenges remain in effectively applying PAC to a wastewater stream. Of particular concern is the application of PAC to existing facilities in which the existing hydraulic profile does not allow the use of large sedimentation tanks normally associated with PAC use in potable water applications. Cloth Media Filtration (CMF) is an existing treatment process that has seen significant saturation into the WWTP market in the United States since being introduced in 1991. While mostly targeted at tertiary treatment, alternate processes such as primary filtration and storm water treatment are now being pursued. It is suspected that CMF will capture and retain Powdered Activated Carbon (PAC) in which the two processes could be combined in order to produce an energy friendly and cost competitive approach to pollutant reductions. This research examines the feasibility of application of PAC into existing hydraulic profiles by using inline injection and its quick removal by Cloth Media Filtration (CMF). One of the most challenging aspects of PAC usage is its removal, which can be facilitated by a commercial CMF. A bench sized cloth media filter was constructed and then operated in a side stream manner with a real-world wastewater treatment train. The results show excellent performance of the designed CMF. The removal of two commercially available PACs was more than 70% within a short time using the existing hydraulic conditions of the plant. Additionally, using the backwash rates and solids removal rates, it was determined that CMF performs as an acceptable means of removal for PAC in a WWTP.
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Date Issued: 2017
Identifier: FSU_SUMMER2017_Madden_fsu_0071N_14114
Format: Thesis

Title: Gas Emissions in Landfills.
Creator: Melaouhia, Haykel, Abichou, Tarek, Chanton, Jeffrey M., Tang, Youneng, Tawfiq, Kamal Sulaiman, Chen, Gang, Florida State University, College of Engineering, Department of Civil...
Show moreMelaouhia, Haykel, Abichou, Tarek, Chanton, Jeffrey M., Tang, Youneng, Tawfiq, Kamal Sulaiman, Chen, Gang, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Environment and natural resources can be polluted and consequently human beings, animals and plants can be impacted. Then, waste management plays an important role in human's life. Landfilling is one of the most common technology for solid waste management (MSW) as an alternative to waste burning and composting. A complex series of biological and chemical reactions is initiated with the burial of solid waste in a landfill, resulting in the production of methane (CH4) and carbon dioxide (CO2)...
Show moreEnvironment and natural resources can be polluted and consequently human beings, animals and plants can be impacted. Then, waste management plays an important role in human's life. Landfilling is one of the most common technology for solid waste management (MSW) as an alternative to waste burning and composting. A complex series of biological and chemical reactions is initiated with the burial of solid waste in a landfill, resulting in the production of methane (CH4) and carbon dioxide (CO2) as the major end products of biological decomposition. With a global warming potential 25 times as high as than carbon dioxide on a century time scale, methane is an important greenhouse gas in the climate system. The fate of this CH4 varies widely depending on typical landfill practice in a specific country. Ideally, all generated CH4 would be captured and used beneficially as an energy source. However, even at modern landfills, some CH4 is released before installation of gas collection systems and some CH4 is released because it is not captured in a collection system. A fraction of the uncollected CH4 is oxidized in the landfill cover through bacterial activities and the rate of CH4 oxidation has recently been reviewed. Thus, estimation of methane emissions from landfills is a crucial task. Several models have been developed through the history for such a task, however, none of them represent the reality of the different phases that methane goes through in the landfill. Moreover, methane oxidation capacity estimation has been only based on stable isotopes method. The objective of this work is to develop new methodologies to quantify methane oxidation capacity within landfill covers and to develop a holistic gas estimation model based on the different phases that gas goes through, generation, collection and oxidation, and this model will be calibrated based on field measurements and historical data available over the United States.
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Date Issued: 2017
Identifier: FSU_2017SP_Melaouhia_fsu_0071E_13859
Format: Thesis

Title: Degradation of Methylene Blue and 1, 4-Dioxane from Groundwater by Pulsed Discharge Non-Thermal Plasma Reactor.
Creator: Zhang, Qiao, Locke, Bruce R., Chella, Ravindran, Tang, Youneng, Florida State University, College of Engineering, Department of Chemical and Biomedical Engineering
Abstract/Description: Plasma generated by strong electric field has been studied for almost 100 years. The plasma-liquid system discharge presents new and interesting applications in the fields of environmental science, material processing and analytical chemistry. Extensive research has focused on exploring the potential application of plasma treatment of organic compounds in wastewater such as phenol, organic dyes, and TCE. The reactor electrode configurations ranges from point to point, point to plate and wire...
Show morePlasma generated by strong electric field has been studied for almost 100 years. The plasma-liquid system discharge presents new and interesting applications in the fields of environmental science, material processing and analytical chemistry. Extensive research has focused on exploring the potential application of plasma treatment of organic compounds in wastewater such as phenol, organic dyes, and TCE. The reactor electrode configurations ranges from point to point, point to plate and wire cylinder. Power supplies include DC, AC, pulsed, and microwave. The goals of the present work were to explore the role of oxygen in a water-film plasma reactor for dye degradation and to combine this non-thermal gas-liquid plasma reactor (NTPR) with a bioreactor to treat 50ppm 1,4-dioxane in groundwater. Two types of power supply were used including an automobile ignition coil driven by DC power supply with a function generator and a nanosecond pulser. No significant additional degradation of methylene blue was detected by adding oxygen into the inlet gas compared to the pure argon case although significant ozone was produced and measured in the gas phase. This is explained by the short gas residence time and low rate of mass transfer preventing the generated ozone to transfer from gas phase into liquid phase as well as by the high reaction rate between OH radical and MB in comparison to the ozone reaction rate. A 50ppm 1,4-dioxane synthetic media was pretreated in the NTPR at five different liquid flowrates (2,5,15,20mL/min). The combined scenario of using plasma treatment at 2ml/min and 1-month microorganism treatment was able to reduce dioxane to below 1μg/L and TOC to below 4 mg C/L.
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Date Issued: 2016
Identifier: FSU_FA2016_Zhang_fsu_0071N_13669
Format: Thesis

Title: Aerated Recirculation and Pressurized Suspended Fiber Biofiltration for the Treatment of Landfill Leachate.
Creator: Wang, Boya, Chen, Gang, Huang, Wenrui, Tang, Youneng, Florida State University, FAMU/FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: ABSTRACT Landfilling is widely adopted as one of the most economical processes for solid waste disposal. At the same time, landfill leachate is also a great environmental concern because of its complex composition and high contaminant concentrations. Recirculating leachate appears to be one of the least expensive methods for partial treatment and disposal of leachate at properly designed and operated landfill sites. The leachate recirculation not only improves the leachate quality, but also...
Show moreABSTRACT Landfilling is widely adopted as one of the most economical processes for solid waste disposal. At the same time, landfill leachate is also a great environmental concern because of its complex composition and high contaminant concentrations. Recirculating leachate appears to be one of the least expensive methods for partial treatment and disposal of leachate at properly designed and operated landfill sites. The leachate recirculation not only improves the leachate quality, but also shortens the time duration required for landfill stabilization. In addition, aerated leachate recirculation can bring air into the landfill, leading to aerobic organic decomposition, as well as iron precipitation. It has been discovered that up to 84% BOD, 86% COD, 90% iron and manganese can be removed after 4 months' recirculation. In Northwest Florida, high concentrations of iron have been observed in the landfill leachate, which is believed to be released to the landfill leachate from iron-rich soil owing to changes in pH and redox conditions induced by organic waste decomposition. Therefore, aerated leachate recirculation has obvious benefits in this region. Although aerated leachate recirculation has these advantages, leachate is only partially treated. The leachate must be further treated in order to meet the discharge requirements. Among all the treatment methods, biological treatment of wastewater with a biofilter is the most promising and most well characterized technology. During biofiltration operations, the growth of microorganisms develops biofilms on the medium surfaces and the microorganisms in the biofilms absorb soluble and colloidal waste materials in the wastewater as it percolates over the medium surfaces. The BOD can nearly be completely removed if the wastewater retention time in the media is sufficiently long for the microorganisms to absorb wastewater constituents. In this research, aerated recirculation and pressurized suspended fiber biofiltration were tested for the treatment of leachate from landfills in Northwest Florida. The pressurized suspended biofilter can efficiently achieve the filtration function with limited space. The suspended fiber provide a tremendous amount of surface areas in a small volume. Therefore, microorganisms can grow around the fibers at a density of greater than 1 × 108 cells per ml, the only means to culture cells at in vivo-like cell density. Another advantage of the pressurized suspended fiber filtration is that the oxygen transfer barrier can be overcome and consequently significantly increased dissolved oxygen level can be achieved. As an innovative technology for wastewater treatment, the pressurized suspended fiber biofilters also makes biological contact oxidation possible, which can significantly improve BOD and COD removal and decrease the sludge yield. For iron removal, contact oxidation is achieved by microbial mediated iron oxidation and fixation during which ferrous iron is oxidized to ferric iron and fixed onto the filter media. Consequently, there is minimal ferric iron suspending in the solution that can escape the filter. Using the combined aerated leachate recirculation and pressurized fiber biofiltration, chemical oxygen demand (COD) of the landfill leachate can be reduced to as low as 8 mg/l and iron content can be reduced to as low as 0.02 mg/l under appropriate dissolved oxygen and alkalinity conditions.
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Date Issued: 2016
Identifier: FSU_2016SP_Wang_fsu_0071N_13128
Format: Thesis

Title: Hydrogen Sulfide Attenuation within Landfill Covers.
Creator: Green, Stefan Larae, Abichou, Tarek, Clark, Clayton J., Chen, Gang, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: There has been much research done on the reduction, or attenuation, of hydrogen sulfide (H2S), particularly within landfill cover soils, as H2S can cause many issues when exposed to the atmosphere. The objective of this research study was to understand hydrogen sulfide (H2S) attenuation within landfill cover soils, and to use mass balancing to determine how much sulfur was retained within each layer of test pad. Both of these were completed through 403 days of monitoring three 65 feet by 35...
Show moreThere has been much research done on the reduction, or attenuation, of hydrogen sulfide (H2S), particularly within landfill cover soils, as H2S can cause many issues when exposed to the atmosphere. The objective of this research study was to understand hydrogen sulfide (H2S) attenuation within landfill cover soils, and to use mass balancing to determine how much sulfur was retained within each layer of test pad. Both of these were completed through 403 days of monitoring three 65 feet by 35 feet lysimeter test pads constructed at the Riverbend Landfill. Test Pad 1 was constructed with 18 inches of local soil and an underlying 6 inch gravel layer. Test Pad 2 was constructed with 12 inches of compost, 6 inches of local soil and an underlying 6 inch gravel layer. Test Pad 3 was constructed with 6 inches of local soil and an underlying 6 inch gravel layer. Monitoring on Test Pad 3 was stopped on April 27th, 2015 due to erosion of the 6 inch soil layer, while Test Pads 1 and 2 were monitored until July 20th, 2015. Readings of landfill gas and H2S inflow, and bottom landfill gas and H2S concentrations were taken in each testing pad on a weekly basis. Bottom H2S loading into the soil layer and top H2S emissions from the soil layer were also measured to determine the removal efficiency of H2S. The average H2S removal efficiency of the test pads is 95%, with Test Pad 1 having a removal efficiency of 99%, Test Pad 2 having a removal efficiency of 99%, and Test Pad 3 having a removal efficiency of 82%. Six soil samples and five water samples were taken to measure sulfur concentration within the testing pads. Soil samples were also taken within each of the layers of each testing location within each test pad to determine the soil type and the water content of each soil layer. Mass balance was calculated by taking the amount of sulfur loaded into the bottom of each testing pad, and subtracting the sum of sulfur loaded into the soil cover, sulfur emitted from the soil cover into the atmosphere, and sulfur removed from the system with water as sulfate. Test Pads 1 and 2 yielded similar results, both retaining about 6000 grams of sulfur within their cover layers, while the results from Test Pad 3 suggest that more sulfur was removed from the system than was originally pushed into the system, which is not possible and suggests errors with either testing methods or the testing pad itself. While the concentrations of sulfur within each test pad layer were measured, there were concerns with their dependability that caused them to not be used to determine the amount of sulfur in each layer.
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Date Issued: 2015
Identifier: FSU_2015fall_Green_fsu_0071N_12959
Format: Thesis

Title: Pyrolysis and Activation of an Invasive Species.
Creator: Mayers, Jordan, Chen, Gang, Ahmad, Hafiz, Clark, Clayton J., Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Invasive plants are a nuisance and a hazard across the United States. Many states spend large amounts of money in an attempt to control and prevent the spread of these plants. This study seeks to take these invasive, low value plants and process them into higher value products. The first step is pyrolysis in which the plant, albizia, is converted into bio-gas, bio-oil, and bio-char. The bio-gas is released while the bio-char and bio-oil are collected. Their basic properties are studied and...
Show moreInvasive plants are a nuisance and a hazard across the United States. Many states spend large amounts of money in an attempt to control and prevent the spread of these plants. This study seeks to take these invasive, low value plants and process them into higher value products. The first step is pyrolysis in which the plant, albizia, is converted into bio-gas, bio-oil, and bio-char. The bio-gas is released while the bio-char and bio-oil are collected. Their basic properties are studied and presented. The bio-char is then further processed to produce activated carbon. Both physical activation with steam and chemical activation with phosphoric acid were evaluated. The carbon showed significantly increased surface area and iodine adsorption. Both physical and chemical activation achieved significant activation with iodine numbers as high as 1000 mg. of I per g. of activated carbon. The results also showed that the yield was significantly increased with the addition of phosphoric acid while maintaining high iodine numbers. As phosphoric acid increased, the yield increased.
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Date Issued: 2014
Identifier: FSU_migr_etd-8841
Format: Thesis

Title: Behavior of Plywood and Fiberglass Steel Composite Tube Structures Subjected to Impact Loading.
Creator: Armaghani, Seyamend Bilind, Jung, Sungmoon, Spainhour, Lisa, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Paratransit buses are custom built as the major vehicle manufacturer produces the custom built passenger cage installed on the chassis for the Paratransit bus. In order for these Paratransit bus members to be sufficient, they have to be evaluated for crashworthiness and energy absorption. This has prompted Florida Department of Transportation (FDOT) to fund research for the safety evaluation of Paratransit busses consisting of crash and safety analysis. There has been a large body of research...
Show moreParatransit buses are custom built as the major vehicle manufacturer produces the custom built passenger cage installed on the chassis for the Paratransit bus. In order for these Paratransit bus members to be sufficient, they have to be evaluated for crashworthiness and energy absorption. This has prompted Florida Department of Transportation (FDOT) to fund research for the safety evaluation of Paratransit busses consisting of crash and safety analysis. There has been a large body of research done on steel subjected to static loads, but more research is needed for steel applied under dynamic loading and high speeds in order to improve crashworthiness in events such as rollovers and side impacts. Bare steel Hollow Structural Section (HSS) tubing are used a lot as structural members of Paratransit buses because of their lightness and progressive buckling under loading. The research will be conducted on quantifying the tubing's behavior under bending by conducting static three point bending and impact loading tests. In addition to the bare tubing, plywood and fiberglass composites are investigated because they are both strong and lightweight and their behavior under dynamic loading hasn't been quantified. As a result, the main purpose of this research is to quantify the differences between the dynamic and static behavior of plywood steel composite and fiberglass steel composite tubing and compare these findings with those of bare steel tubing. The differences will be quantified using detailed and thorough experiments that will examine the composites behavior under both static and dynamic loading. These tests will determine if there are any advantages of using the composite materials and thus allow for recommendations to be made to the FDOT with the goal of improving the safety of Paratransit busses. Tensile tests were conducted to determine the material properties of the tested specimens. Before the static and dynamic experiments are run to investigate the differences between static and dynamic behavior, Preliminary three point bending testing was conducted to determine the parameters for the final experiments. Static bending testing was conducted on the bare, plywood composite, and fiberglass composite steel tubing. The point of these experiments was to produce a Moment vs. Rotation plot to determine the specimens' maximum moments and their associated rotation, as that is when the steel buckles and fails. The dynamic three point bending experiments were conducted using the impact loading apparatus and had the same purpose as the static experiments. For both static and dynamic experiments, the performances of the different types of specimens were compared based upon their Moment vs. Rotation plots. This will determine the effect that the composite has on the rotation and maximum moment at which the tubing fails. After conducting these experiments, amplification factors were established for each specimen by comparing the maximum moment and their associated rotation between static and dynamic testing. λ was calculated to quantify the ratio between the static and dynamic maximum moments. β was used to quantify the ratio between the rotation needed to produce the maximum moment between static and dynamic events. A small amplification factor denotes that material performs well under impact loading and the material doesn't experience dramatic change in behavior during dynamic events. Amplification factors were compared between the bare, plywood, and fiberglass composite steel tubing in order to evaluate the performance of the composites. After comparing the amplification factors of the different types of tubing, recommendations can be made. Fiberglass and plywood composite were shown to be valuable because it decreased the effect of dynamic forces as β was reduced by a factor of 2 in comparison to bare tubing. Based upon the amplification factors, it was recommended to use 14 gauge fiberglass composite tubing as Paratransit bus structural members because it was affected the least by dynamic loading.
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Date Issued: 2014
Identifier: FSU_migr_etd-8933
Format: Thesis

Title: E.Coli Growth and Transport in the Presence of Nanosilver under Variable Growth Conditions.
Creator: Xie, Weijie, Chen, Gang, Huang, Wenrui, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Nanosilver has the ability to anchor to the bacterial cell wall and subsequently penetrate it, thereby causing structural changes in the cell membrane and death of the cell. The bacterial responses to the presence of nanosilver usually vary depending on the concentration of nanosilver particles, exposure conditions and the bacterial physiological stage. Since bacterial anabolism dependents upon a stoichiometric ratio of carbon and inorganic nutrients, the carbon to nitrogen ratio (C/N) thus...
Show moreNanosilver has the ability to anchor to the bacterial cell wall and subsequently penetrate it, thereby causing structural changes in the cell membrane and death of the cell. The bacterial responses to the presence of nanosilver usually vary depending on the concentration of nanosilver particles, exposure conditions and the bacterial physiological stage. Since bacterial anabolism dependents upon a stoichiometric ratio of carbon and inorganic nutrients, the carbon to nitrogen ratio (C/N) thus plays an important role of bacterial responses to the exposure of nanosilver. This study investigated the responses of Escherichia coli to the exposure of nanosilver under variable growth conditions. It was discovered that E. coli grown under different growth conditions had least resistance to the toxicity of nanosilver when cultured under carbon limited conditions. However, the presence of rhamnolipid, a commonly utilized biosurfactant for soil remediation increased the resistance of E. coli to nanosilver. The transport of E. coli cultured under carbon limited conditions was further studied in silica sand columns. E. coli adsorption in silica sand increased when cultured in the presence of nanosilver. On the contrary, E. coli adsorption in silica sand was significantly reduced when cultured in the presence of rhamnolipid. The results suggest that the resistance of E.coli to nanosilver can be improved by diminishing the carbon limitation in growth condition and the transport impact of nanosilver can be diminished by adding rhamnolipid.
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Date Issued: 2014
Identifier: FSU_migr_etd-8921
Format: Thesis

Title: Buildings' Sustainability Analysis: Analytical Hierarchy Process to Analyze Cost, Leed Credits, and Carbon Neutrality Utilizing a Building Information Modeling Platform.
Creator: Doczy, Ryan, AbdelRazig, Yassir A., Sobanjo, John O., Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: For building owners, there are several factors that they must consider when thinking about whether or not a building has achieved the goals set up for it. With increases in energy prices, knowledge about the damage being done to our atmosphere by humanity, and an increased drive towards environmental stewardship, sustainability has become more and more of a priority for building owners. A problem that building owners face when designing a building is trying to create a proper balance between...
Show moreFor building owners, there are several factors that they must consider when thinking about whether or not a building has achieved the goals set up for it. With increases in energy prices, knowledge about the damage being done to our atmosphere by humanity, and an increased drive towards environmental stewardship, sustainability has become more and more of a priority for building owners. A problem that building owners face when designing a building is trying to create a proper balance between reducing immediate costs and increasing the "greenness" of a building. The construction industry's technological breakthroughs and growing experience constructing green buildings is causing even those without sustainable inclinations to have to consider the possibility of going green due to the perceived benefits. Owners now have to consider that while sustainable construction drives up the upfront costs of costs of buildings, it also reduces long term costs (e.g. utility bills) while also increasing potential benefits associated with building green (e.g. increasing worker productivity). Due to the implications that these decisions will have on the owner and the building's occupants, the owner needs to have a tool to be able to assist them in determining what building design alternatives are helping the owner achieve his or her goals. The objectives of this research consist of the following (1) develop a decision making tool that is a hybrid of the analytical hierarchy process and the multiple attribute utility theorem; (2) design the decision making tool to take user inputs and determine how close a project came to meeting its goals; (3) set up the model to allow the user to be able to compare alternatives and chose the one that best meets the cost, LEED, and net-zero/carbon neutral goals
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Date Issued: 2014
Identifier: FSU_migr_etd-8767
Format: Thesis

Title: Ground Tire Rubber as a Component Material in Concrete Mixtures for Paving Concrete.
Creator: Twumasi-Boakye, Richard, Sobanjo, John, Tawfiq, Kamal, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The management of solid waste is a major environmental concern in the United States. Waste tire rubber forms a major part of this problem and a rather severe one since tire rubbers are not biodegradable hence its disposal into landfills are of great concern. This research primarily focused on finding the best way of producing paving concrete with the use of ground tire rubber as a component material. Tests on rubber concrete were performed in two stages. Preliminary tests were performed using...
Show moreThe management of solid waste is a major environmental concern in the United States. Waste tire rubber forms a major part of this problem and a rather severe one since tire rubbers are not biodegradable hence its disposal into landfills are of great concern. This research primarily focused on finding the best way of producing paving concrete with the use of ground tire rubber as a component material. Tests on rubber concrete were performed in two stages. Preliminary tests were performed using both 40-mesh GTR and 3/8-inch rubber chips (RC) to replace fine aggregates and coarse aggregates respectively by weight in the concrete mix. This stage of testing considered zero to 40 percent GTR replacement of fine aggregates by weight at 10 percent increment and for zero to 30 percent RC replacement of coarse aggregates by weight at 10 percent increment. Observations from this stage guided the formulation of a second and final stage of testing which involved only zero to 20 percent GTR replacement of fine aggregate by weight at 5 percent increment. The mix design for this stage involved the use of water reducers, air-entrainer and fly-ash. In addition to concrete mechanical property tests, coefficient of thermal expansion (CTE), plastic shrinkage and drying (free) shrinkage tests were also conducted. Results from preliminary tests indicated that GTR and RC concrete specimens were of relatively low strength, improved toughness and showed more elasticity when compared to normal concrete specimens. The final stage of laboratory testing however showed improved strength characteristics, with the initial observations of improved toughness and low modulus of elasticity still evident. Coefficient of thermal expansion (CTE) test results did not show significant difference between mix-types, with the range of results falling within the typical limit for normal concrete. Plastic shrinkage test results showed that the inclusion of GTR helped in reducing plastic shrinkage cracks in concrete. Preliminary results at the second stage testing on drying shrinkage using 10% GTR concrete indicated a reduction in free shrinkage when compared to the control specimens.
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Date Issued: 2014
Identifier: FSU_migr_etd-9107
Format: Thesis

Title: Development of the Gas Push Pull Test for Hydrogen Sulfide Oxidation.
Creator: Lawson, Jacob Brinton, Abichou, Tarek, Chanton, Jeffery, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: ABSTRACT A limited number of studies using various types of cover materials to attenuate H2S emissions have been performed both at the laboratory and field scales. These results have demonstrated that H2S emissions can be effectively reduced using compost, fine concrete, and lime-amended sandy soils as cover materials using several mechanisms (Plaza et al. 2007, Xu, 2005, Sungthong 2010). These mechanisms are: (1) Hydrogen sulfide is consumed by bacteria found in soil that oxidizes hydrogen...
Show moreABSTRACT A limited number of studies using various types of cover materials to attenuate H2S emissions have been performed both at the laboratory and field scales. These results have demonstrated that H2S emissions can be effectively reduced using compost, fine concrete, and lime-amended sandy soils as cover materials using several mechanisms (Plaza et al. 2007, Xu, 2005, Sungthong 2010). These mechanisms are: (1) Hydrogen sulfide is consumed by bacteria found in soil that oxidizes hydrogen sulfide to elemental sulfur or sulfate, (2) Clay or organic matter in soils may also sorb hydrogen sulfide (soil microorganisms are not involved in the sorption process), and (3) H2S may be oxidized by reaction with soil minerals, particularly ferric iron. Such mechanisms are well understood from the significant amount of research performed on H2S gas removal using biofiltration. Additionally, under aerobic landfill cover conditions, considerable research has been performed using microbiological methane oxidation to mitigate methane emissions from municipal solid waste. One of the main issues regarding the implementation of approaches for the reduction of H2S emissions from landfills is the lack of a proper technique to assess the level of H2S oxidation and reaction under field conditions. Developing such a technique would allow the determination of H2S oxidation capacity of different cover materials and different cover designs under different climatic conditions. One possible technique that could be employed is the Gas Push Pull Test (GPPT). The general aim of this thesis is to develop the GPPT method for a reactive gas like H2S, which has not been done before. GPPT is a single well gas-tracer test in which inert gases are used as non-reactive tracers for the reactive gas (methane) or in this case, H2S. During the test, a mixture of tracer and reactive gases is injected (pushed) into the soil. During a transition phase, the soil "air" mixes with the injected gases where it is available to microorganisms or minerals. The mixture of soil "air" and injected gas is then extracted (pulled) from the same location. The quantification of oxidation is then based on the analysis of the breakthrough curves (relative concentrations) of the reactive and the tracer gases. It is expected that the tracer concentrations at the injection/extraction points decrease as a result of physical transport processes, whereas the attenuation of the reactive gas is a result of physical transport processes, chemical oxidation, and microbial (and others) activities. A lab study was completed to assess the reactivity of H2S by different soil types typically used in landfill cover construction. The reactivity of H2S was characterized by zeroth-order kinetics as well as correlating the reactivity to water and iron content of the soil materials. The lab study only investigated physical and chemical processes that attenuate H2S. In addition to the laboratory study, a field study was completed to develop proper methods in performing a (GPPT) to measure the capacity of soil materials to oxidize H2S. The objectives were to experimentally compare transport of the reactant gas H2S and tracer gases during GPPTs as a function of varying injection/extraction flow rates in a porous medium and in the absence of microbial activity. Additionally, the relative importance of molecular diffusion, advection, and transfer into the water phase of H2S during GPPTs was also evaluated as well as developing a correction ratio that would allow the use of tracers with dissimilar molecular weights.
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Date Issued: 2013
Identifier: FSU_migr_etd-7878
Format: Thesis

Title: Empirical Deck for Phased Construction and Widening.
Creator: Fuentes, Javier Alexander Muniz, Tawfiq, Kamal, Sobanjo, John O., Spainhour, Lisa K., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: A standard deck is defined as a deck slab on longitudinal beams with main reinforcement placed perpendicular to traffic. As outlined in Article 9.6.1 of the AASHTO-LRFD Bridge Design Specifications, it allows three design methods or procedures of bridge decks with primary reinforcement perpendicular to the main bridge beams Approximate Elastic or "Strip" Method of Analysis (AASHTO 4.6.2.1) Traditionally bridge deck designs have always been made by analyzing assumed transverse slab strips...
Show moreA standard deck is defined as a deck slab on longitudinal beams with main reinforcement placed perpendicular to traffic. As outlined in Article 9.6.1 of the AASHTO-LRFD Bridge Design Specifications, it allows three design methods or procedures of bridge decks with primary reinforcement perpendicular to the main bridge beams Approximate Elastic or "Strip" Method of Analysis (AASHTO 4.6.2.1) Traditionally bridge deck designs have always been made by analyzing assumed transverse slab strips within the concrete deck as flexure members and supported by the existing girders. This method is called the Approximate Method of Analysis. To simplify the length and complexity of the design, it is assumed that the girders are rigid supports. In addition, AASHTO specifications allow the maximum positive moment and the maximum negative moment to apply for all positive moment regions and all negative moment regions in the slab, respectively. Refined Methods of Analysis (AASHTO 4.6.3) - Refined Methods of Analysis are generally acceptable methods for analyzing concrete bridge decks. These methods are based mainly on finite element analysis, which requires a more complicated and lengthy set of calculations. Thus, these various methods are not typically used to analyze a standard or "typical" bridge deck. A refined analysis method would be better suited for a more complex deck slab structure, which would require a more detailed analysis. Empirical Method of Analysis (AASHTO 9.7.2) - Empirical Method of Analysis is generally based on the concept of internal "arching action" within concrete slab. In other words, the deck behaves more like a "continuous membrane" than a series of contiguous beams. This method takes into account in plane stresses generated by applying load to the deck. These in plane forces, which in traditional design are ignored, act to strengthen the overall response of the deck. This design procedure is generally accepted and is widely adopted and employed by many other countries and in-state agencies. This project was initiated with the goals of assessing the current and possibly future design methodologies to be used by the Florida Department of Transportation in future bridge deck design projects. This thesis focuses on evaluating and contrasting the benefits and disadvantages of the Traditional Method of Analysis (currently in general use by the FDOT) and the empirical method of analysis. This objective is achieved by conducting a Finite Element Analysis parametric study using specialized computer software, where a typical bridge is designed and tested based on designs derived from said methods. The analysis yielded data that was then collected, analyzed and used for benchmark purposes. This study allowed an extensive range of specimens to be tested, and a broad range of loads and reinforcement combinations to be analyzed using both methodologies. From the results obtained, potential recommendations were then formulated in contrast to current design practices.
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Date Issued: 2013
Identifier: FSU_migr_etd-8609
Format: Thesis

Title: Development Device for Prestressing Strands in Beams.
Creator: Wagner, David J., Roddenberry, Michelle, Tawﬁq, Kamal, Mtenga, Primus, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: A grouted sleeve device for gripping prestressing steel, developed and tested in previous research by Potter 2009, was embedded into the end regions of prestressed concrete bridge beams in an attempt to anchor the terminal ends of the strands. The goal was to produce enough bond strength in the device to effectively act as a strand anchor and reduce the development length of the strand. Anchored strand could also serve to increase ductility, improve ultimate capacity and reduce the number of...
Show moreA grouted sleeve device for gripping prestressing steel, developed and tested in previous research by Potter 2009, was embedded into the end regions of prestressed concrete bridge beams in an attempt to anchor the terminal ends of the strands. The goal was to produce enough bond strength in the device to effectively act as a strand anchor and reduce the development length of the strand. Anchored strand could also serve to increase ductility, improve ultimate capacity and reduce the number of stirrups required in the end region. Four test series were performed, each focusing on separate aspects of the research. Test Series 1 focused on prestress release testing using 0.6-in.-diameter prestressing strand with different steel sleeve sizes and grout types; the results of these tests were used to finalize the anchorage device design. Series 2 incorporated two different designs into the fabrication of two half-scale AASHTO Type II prestressed concrete beams. These beams were fitted with strain gauges for monitoring the transfer length during detensioning. In Series 3, the beams from the previous test series were tested in a shear test configuration to failure, and results were compared to a control specimen. For Series 4, unstressed pull-out specimens were created to test the bond performance of the second anchorage type embedded in a beam of Series 2 and 3. Finalization of device design and field installation method in Test Series 1 provided a path for the research to take. The transfer length testing that followed established that reducing the transfer length (Lt) in a prestressed beam by means of an embedded anchor was possible. Improvement of the transfer length due to the grouted device is considered negligible after accounting for concrete strength, but the second anchor type (coil confinement) showed a reduction in Lt of 30%. Both types of embedded anchors showed an improvement in ductility and ultimate capacity, but proper end region detailing using shear steel would be beneficial in future tests to more thoroughly test the performance of the anchor.
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Date Issued: 2013
Identifier: FSU_migr_etd-7642
Format: Thesis

Title: Side Impact of a Paratransit Bus.
Creator: Turley, Joshua, Jung, Sungmoon, Wekezer, Jerry, Rambo-Roddenberry, Michelle, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Florida Department of Transportation--Transit Office has endeavored to quantify the safety of a paratransit bus in a side impact collision. They have provided funded to produce this work. The goal of this work is to determine the likeliness that an occupant in a paratransit bus will experience an unacceptable amount of harm during a side impact collision. A side impact experiment was performed. An impactor weighing 4,400 lbs consisting of a crash cart with an attached IIHS deformable...
Show moreThe Florida Department of Transportation--Transit Office has endeavored to quantify the safety of a paratransit bus in a side impact collision. They have provided funded to produce this work. The goal of this work is to determine the likeliness that an occupant in a paratransit bus will experience an unacceptable amount of harm during a side impact collision. A side impact experiment was performed. An impactor weighing 4,400 lbs consisting of a crash cart with an attached IIHS deformable barrier was suspended between two steel towers. The impactor was raised to a height of 31 ft and let swing into the side of a stationary paratransit bus in a pendulum motion impacting at an angle of 90 degrees. Inside the bus a Hybrid III 50th percentile Anthropomorphic Test Dummy (ATD) was seated near the region of impact. The ATD recorded values that were all below Injury Assessment Reference Values (IARV) which indicates a favorable crashworthiness result for a side impact of similar paratransit bus. There was a significant amount of crush in the deformable barrier where it contacted the bus deck and indicates that should the impactor impact the bus higher or the bus have a low deck construction the results may be significantly different. This should be investigated in future research.
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Date Issued: 2013
Identifier: FSU_migr_etd-7632
Format: Thesis

Title: Analysis of Tilt-Up Building Design and Industry Standard Practices in Tornado-Prone Regions.
Creator: Maldonado, Desiderio, Rambo-Roddenberry, Michelle, Jung, Sungmoon, Mtenga, Primus, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Tilt-up buildings are a popular building construction method used across the United States. These structures offer many benefits, but can also present unique design challenges when compared to other building types. Recent tornado outbreaks have caused over $20 billion in total damages and killed hundreds of people. As with most structures, tilt-up buildings tend to be susceptible to tornado events. These events have brought building performance and safety in tornado-prone regions to the...
Show moreTilt-up buildings are a popular building construction method used across the United States. These structures offer many benefits, but can also present unique design challenges when compared to other building types. Recent tornado outbreaks have caused over $20 billion in total damages and killed hundreds of people. As with most structures, tilt-up buildings tend to be susceptible to tornado events. These events have brought building performance and safety in tornado-prone regions to the forefront of consideration by residents, building owners, code officials, and design professionals. The research for this thesis was performed to study the major components and connections used in typical tilt-up buildings using current standard wind analysis methods and to identify limiting factors in building performance in hopes of improving future building designs. Standard wind design and analysis methods were used for this research, not tornado-specific wind design criteria. The components focused on are generally regarded as current industry standards and follow local building codes and manufacturer recommendations. Existing retrofit options traditionally used in high seismic regions were also studied to see if any available methods were suitable for preventing tilt-up building failure in tornado events. The construction of internal storm shelters was also investigated as a potential additional method of reducing injuries and deaths in tornado-prone regions. While large tornado-proof buildings may be impractical or cost prohibitive, it is important for design professionals to continue to take proactive approaches to region specific hazards in future designs to reduce property damage and casualties.
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Date Issued: 2013
Identifier: FSU_migr_etd-7484
Format: Thesis

Title: Determination of Optimum Lengths of Active and Inactive Elements of a Segmented Sensor for Discriminating Among Single, Super Single, and Dual Tires.
Creator: Conrad, Adam, Moses, Ren, Sobanjo, John, AbdelRazig, Yassir, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Monitoring traffic through extensive collection and efficient storage of traffic data is crucial for improving safety and efficiency of Florida Highways. To this end, the Florida Department of Transportation operates temporary and permanent count stations strategically placed at various locations on the state highway system. The data collected by electronic equipment installed at these stations include individual vehicle records composed of a number of axles per vehicle, axle spacing, overall...
Show moreMonitoring traffic through extensive collection and efficient storage of traffic data is crucial for improving safety and efficiency of Florida Highways. To this end, the Florida Department of Transportation operates temporary and permanent count stations strategically placed at various locations on the state highway system. The data collected by electronic equipment installed at these stations include individual vehicle records composed of a number of axles per vehicle, axle spacing, overall vehicle length, and operating speed. The Florida Department of Transportation operates other sites categorized as weigh-in-motion (WIM) sites that are set up to additionally collect individual axle weights and overall gross vehicle weight. In general, the traffic count program managed by the FDOT Statistics Office is operating very well and serves a vital purpose of supporting federal, state, and private user needs. Nevertheless, the FDOT Statistics Office continues to experience a number of challenges in operating the count sites, in assuring the quality of data collected by these sites, and in complying with continually changing federal reporting requirements. The following research aims to provide the FDOT Statistics Office with an improved device to classify vehicles on all desired roadways. The research effort consisted of collecting vehicular data, conducting statistical analyses and developing equations. It was determined that a segmented sensor would provide FDOT with an improved system by having the capability to determine the class of vehicle driving over it. A sensor length recommendation was made that will accurately determine the type of tire running overhead. This paper will take the reader through the process of coming to the aforementioned conclusions.
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Date Issued: 2013
Identifier: FSU_migr_etd-8686
Format: Thesis

Title: The Efficacy of Aeration and GAC Filtration at Reducing Microtoxicity of Water.
Creator: Michaud, Gustave, Chen, Gang, Barbu, Adrian, Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Chlorination of water is among the cheapest and mostly widely used drinking water disinfection methods. It also produces many disinfection by-products (DBPs) that are considered carcinogenic. DBPs are the result of chlorine reaction with dissolved organic carbon (DOC) in water. This study seeks to evaluate a solution for the removal of DBPs, namely bubble column aeration in conjunction with granulated activated carbon (GAC) filtration. Trihalomethanes (THMs), which are one of the two major...
Show moreChlorination of water is among the cheapest and mostly widely used drinking water disinfection methods. It also produces many disinfection by-products (DBPs) that are considered carcinogenic. DBPs are the result of chlorine reaction with dissolved organic carbon (DOC) in water. This study seeks to evaluate a solution for the removal of DBPs, namely bubble column aeration in conjunction with granulated activated carbon (GAC) filtration. Trihalomethanes (THMs), which are one of the two major types of DBPs produced by chlorination, are volatile and therefore can be removed by aeration. This study also seeks to evaluate the effectiveness of aeration as a form of pre-treatment, if removal of DOC is achieved. The results show that GAC filtration is very efficient at removing DOC, and microtoxicity in neutral pH synthetic surface water. Bubble Column aeration alone, however, is not effective at removing DOC. The results also show that aeration improves the efficiency of GAC filtration at reducing microtoxicity of water. The t-test between toxicity values for the GAC filtration set-up, and the GAC/Bubble column aeration set-up indicate that the two methods give a difference in values that is statistically significant. It is concluded that chlorination followed by a GAC/Bubble column aeration filtration system is a viable treatment method. Alternative treatment technologies such as ozone and chlorine dioxide create DBPs that are carcinogens, or considered potential carcinogens.
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Date Issued: 2013
Identifier: FSU_migr_etd-8603
Format: Thesis

Title: The Use of O₃ Advanced Oxidation Processes for Landfill Leachate Pretreatment.
Creator: Ghazi, Niloufar Mirsaeid, Chen, Gang, Clark, Clayton, Abichou, Tarek, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The final discharge point for collected landfill leachates is frequently the local municipal wastewater treatment facility. The salinity, color, and/or nutrient and organics contamination of leachates often necessitate some form of pre-treatment. When advanced oxidation processes (AOPs) are considered for pre-treatment, the unique composition of dissolved organic matter (DOM) and the relatively high concentrations of some inorganic solutes in leachate will inhibit treatment efficiency. The...
Show moreThe final discharge point for collected landfill leachates is frequently the local municipal wastewater treatment facility. The salinity, color, and/or nutrient and organics contamination of leachates often necessitate some form of pre-treatment. When advanced oxidation processes (AOPs) are considered for pre-treatment, the unique composition of dissolved organic matter (DOM) and the relatively high concentrations of some inorganic solutes in leachate will inhibit treatment efficiency. The most important benchmark for design of AOPs is the expected steady-state production of free radical (*OH). Without a quantitative assessment of total *OH consumption in high-strength waste water, like a landfill leachate, efficient AOP treatment is uncertain. For this reason, two landfill leachates, distinct in color, DOM, population served by municipal solid waste facility, and age of landfill, were characterized for *OH-scavenging using a well-established competition kinetics method. After stripping the samples of inorganic carbon, the DOM in leachate from mature (stabilized) landfill was found to react with *OH at a rate of 9.76 x 108 M-1s-1. However, DOM in leachate from newer landfill was observed to scavenge available *OH at a faster rate (8.28 x 109 M-1s-1). The combination of fast rate of reaction with *OH and abundance of DOM in the sampled leachate severely limited the contribution of *OH to degradation of an O3- and *OH-labile organic probe compound (bisphenol-a) in the ozonated mature leachate (f*OH= 0.03). Substantial dosing of both O3 and H2O2 (> 70 mg/L and >24 mg/L, respectively) may be required to see at least 1-log-removal (>90%) of an *OH-selective leachate contaminant (parachlorobenzoic acid) in a mature landfill leachate.
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Date Issued: 2013
Identifier: FSU_migr_etd-8606
Format: Thesis

Title: Power Generation and Nitrogen Removal of Landfill Leachate Using Microbial Fuel Cell Technology.
Creator: Lee, Yongwoo, Chen, Gang, Clark, Clayton J., Ahmad, Haﬁz, Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Microbial fuel cell (MFC) technology has been practiced in the treatment of landfill leachate. However, it is a big challenge for the usage of MFCs to treat landfill leachate with high ammonium content. The purpose of this study was to design and test two MFC reactors, i.e., an ammonium oxidation/MFC re- actor and a MFC/Anammox reactor for the treatment of landfill leachate with high ammonium content in terms of power generation and nitrogen removal. Using the ammonium oxidation/MFC reactor,...
Show moreMicrobial fuel cell (MFC) technology has been practiced in the treatment of landfill leachate. However, it is a big challenge for the usage of MFCs to treat landfill leachate with high ammonium content. The purpose of this study was to design and test two MFC reactors, i.e., an ammonium oxidation/MFC re- actor and a MFC/Anammox reactor for the treatment of landfill leachate with high ammonium content in terms of power generation and nitrogen removal. Using the ammonium oxidation/MFC reactor, the landfill leachate collected from Leon County Landfill of Northwest Florida generated a power density of 8 mW/m2 together with 92% of nitrogen removal. For the MFC/Anammox reactor, a power density of 12 mW/m2 was achieved with 94% of nitrogen removal. Compared with the ammonium oxidation/MFC reactor, 50% more energy was generated because in the MFC/Anammox Reactor, nitrite served as the electron acceptor; while in the Ammonium Oxidation/MFC reactor, nitrate served as the electron acceptor. In this research, power generation was also found to be directly linked to the microbial species that were involved in organic decomposition, i.e., the greater the microbial concentration, the more power generated.
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Date Issued: 2013
Identifier: FSU_migr_etd-8588
Format: Thesis

Title: Investigation of Carbon Fiber Composite Cables (CFCC) in Prestressed Concrete Piles.
Creator: Joshi, Kunal, Rambo-Roddenberry, Michelle, Mtenga, Primus, Jung, Sungmoon, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Florida Department of transportation most commonly uses prestressed concrete piles as foundation in bridges. It has been observed since past few years that the piles installed in aggressive marine environments are subjected to corrosion which generates a need to retrofit them. Although many solutions have been applied to address this issue, these solutions have seem to be ineffective in long term and hence use of advanced materials in piles, to avoid degradation due to corrosion, is...
Show moreThe Florida Department of transportation most commonly uses prestressed concrete piles as foundation in bridges. It has been observed since past few years that the piles installed in aggressive marine environments are subjected to corrosion which generates a need to retrofit them. Although many solutions have been applied to address this issue, these solutions have seem to be ineffective in long term and hence use of advanced materials in piles, to avoid degradation due to corrosion, is necessarry. The ACI and AASHTO equations used to determine the bond properties of a prestressing strand, need to be satisfied by this material, to render this material's suitability as replacement to steel strands. 5--24 in. square prestressed concrete piles which included 3--40 ft. piles and 2--100ft. piles, were cast using 0.6in. diameter carbon fiber composite cables manufactured by Tokyo Rope Mfg. Co. to asses the performance of CFCC as reinforcement. A different anchoring system was used to anchor the CFCC to the abutment in order to prestress the strands. Transfer length was monitored on each pile end and compared to the ACI and AASHTO equations to evaluate the bond characteristics of the CFCC. In addition to that, development length tests and flexural tests were performed at the Marcus. H. Ansley research laboratory to further judge the bond properties of the CFCC with concrete. The results of these tests show if the performance of CFCC is comparable to steel and also describe the technique used to prestress these strands. The 2--100 ft. piles were cast to be driven on site to monitor the static resistance of the piles and would be long term monitored to asses the performance of CFCC against corrosion.
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Date Issued: 2013
Identifier: FSU_migr_etd-8578
Format: Thesis

Title: Rhamnolipid Biosurfactant Adsorption and Transport in Biochar Amended Agricultural Soil.
Creator: Vu, Kien Anh, Chen, Gang, Clark, Clayton, Ahmad, Hafiz, Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Rhamnolipid biosurfactant is a bacterial biosurfactant produced by several Pseudomonas species, which can wet hydrophobic soils by lowering the cohesive and/or adhesive surface tension, allowing the water to spread out more evenly and better penetrate the hydrophobic soils. Because of its bio-degradability, rhamnolipid biosurfactant applications bring minimal adverse impact on the soil and groundwater as compared with that of chemical wetting agents. Rhamnolipid biosurfactant applications...
Show moreRhamnolipid biosurfactant is a bacterial biosurfactant produced by several Pseudomonas species, which can wet hydrophobic soils by lowering the cohesive and/or adhesive surface tension, allowing the water to spread out more evenly and better penetrate the hydrophobic soils. Because of its bio-degradability, rhamnolipid biosurfactant applications bring minimal adverse impact on the soil and groundwater as compared with that of chemical wetting agents. Rhamnolipid biosurfactant applications save the water consumptions during agricultural irrigation, especially under draught conditions. This research was designed to investigate the applications of rhamnolipid biosurfactant applications in agricultural soils. Performance of rhamnolipid biosurfactant in intact soil columns collected from agricultural soils was explored and related to the soil and wetting agent properties. In addition, the impact of the organic concentration of wetting agent fate and transport was investigated. The results show that Rhamnolipid biosurfactant may lower the water surface tension (relates to Gibbs free energy of the interaction between rhamnolipid biosurfactant molecules), and wet the agricultural soil samples. The critical micelle concentration (CMC) of rhamnolipid biosurfactant, which is defined as the minimum concentration to form the initiate micelle, is about 40 mg/L. Moreover, the adsorption isotherm of rhamnolipid biosurfactant on the soil is inversely proportional to the increase of concentration of surfactant due to the formation of micelle. But this adsorption isotherm is not dependent to the concentration of biochar-amended soils. The column transport of rhamnolipid biosurfactant is also explored. The results show that the thermodynamic properties of rhamnolipid biosurfactant may control its transport. The retention time of rhamnolipid biosurfactant on the soil changes over the time (pore volume) due to its soprtion, but does not relate to the concentration of biochar-amended soil samples. This transport may also be represented by the advection-dispersion equation with a local equilibrium assumption. The results prove that we may apply rhamnolipid biosurfactant and biochar in the agricultural soils in subtropical area. This application will enhance the water containing ability of soil for crop purpose, and improve the properties of soil.
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Date Issued: 2013
Identifier: FSU_migr_etd-8654
Format: Thesis

Title: Static Structural Implications of Bridge Pile Bents by Vessel Impact under Scoured Conditions.
Creator: Fung, Kakit, Sobanjo, John, Tawfiq, Kamal, Jung, Sungmoon, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Local scour has been a leading cause of bridge failure. The erosion of the soil at the bottom of the piles causes changes in the structural integrity of the bridge. Bridge piles are most vulnerable during the occurrence of scour and the process of the scour holes refilling. Outside forces such as vessel impact can occur and cause failure at that time. This solidifies the reason for providing insight on the structural implications of vessel impact on bridge substructures under scoured...
Show moreLocal scour has been a leading cause of bridge failure. The erosion of the soil at the bottom of the piles causes changes in the structural integrity of the bridge. Bridge piles are most vulnerable during the occurrence of scour and the process of the scour holes refilling. Outside forces such as vessel impact can occur and cause failure at that time. This solidifies the reason for providing insight on the structural implications of vessel impact on bridge substructures under scoured conditions in hopes that failure can be prevented. This research involves using FB-Multipier; a nonlinear finite element based program to analyze bridge pile bent induced with impact forces under scoured conditions. The first part of the research deals with exploring the working condition of pile bent under normal flood and scour conditions. The second part deals with the addition of vessel impact striking the substructure. The occurrence of these two conditions occurs under the assumption of an extreme load event occurring. The changes monitored in the piles were as follows: lateral resistance in the piles when scour occurs; demand/capacity; their fixity based on scour depth; and pile-load interaction. The parameters such as soil properties, bent dimensions, and hydraulic data are modeled after the Ernest Lyons West Island Access Bridge in Florida. This provides actual data that can be used as considerations for similar bridges. The results mimic the expectations established in the hypothesis. Besides this, interaction behavior of the applied force and piles are found. First off, the location of the applied lateral force is important. It greatly influences the static changes. Maximum shear occurs at the top of the soil during the unscoured and scoured conditions. Maximum negative moment does indeed occur at the fixity depth.
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Date Issued: 2013
Identifier: FSU_migr_etd-7382
Format: Thesis

Title: Rhamnolipid Biosurfactant Transport in Agricultural Soils.
Creator: Renfro, Tyler D., Chen, Gang, Clark, Clayton, Watts, Michael, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Rhamnolipid biosurfactant is a bacterial biosurfactant produced by several Pseudomonas species, which can wet hydrophobic soils by lowering the cohesive and/or adhesive surface tension, allowing the water to spread out more evenly and better penetrate the hydrophobic soils. Because of its bio-degradability, rhamnolipid biosurfactant applications cause minimal adverse effects to the soil and groundwater as compared with that of chemical wetting agents. Rhamnolipid biosurfactant applications...
Show moreRhamnolipid biosurfactant is a bacterial biosurfactant produced by several Pseudomonas species, which can wet hydrophobic soils by lowering the cohesive and/or adhesive surface tension, allowing the water to spread out more evenly and better penetrate the hydrophobic soils. Because of its bio-degradability, rhamnolipid biosurfactant applications cause minimal adverse effects to the soil and groundwater as compared with that of chemical wetting agents. Rhamnolipid biosurfactant applications save water consumption during agricultural irrigation, especially under draught conditions. This research was designed to investigate the effectiveness of rhamnolipid biosurfactant applications in agricultural soils and key functioning properties. Performance of the rhamnolipid biosurfactant was explored in intact soil column experiments using agricultural soil. Investigating the impact of the rhamnolipid biosurfactant wetting agent fate and transport of organic concentration. Concluding rhamnolipid biosurfactants work effectively at low concentrations, from 12 to 6 percent and would be suitable for biosurfactant production and use.
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Date Issued: 2013
Identifier: FSU_migr_etd-7571
Format: Thesis

Title: The Effects of Silver Nanoparticles on Wastewater Treatment and Escherichia Coli Growth.
Creator: Perez, Michael, Department of Civil and Environmental Engineering
Abstract/Description: Nanomaterials and their increasing use in manufactured products are of great concern to wastewater treatment systems and the environment. Nanosilver has become one of the most popular nanoparticles due to its many applications and relatively low manufacturing costs. It is currently being used for a wide variety of commercial products including medical applications, water purification, antimicrobial uses, paints, coatings, food packaging. Impregnating other materials with silver nanoparticles...
Show moreNanomaterials and their increasing use in manufactured products are of great concern to wastewater treatment systems and the environment. Nanosilver has become one of the most popular nanoparticles due to its many applications and relatively low manufacturing costs. It is currently being used for a wide variety of commercial products including medical applications, water purification, antimicrobial uses, paints, coatings, food packaging. Impregnating other materials with silver nanoparticles is a practical way to exploit the germ fighting properties of silver (Nanotechnology 2006). In clothing such as socks, nanosilver may restrict the growth of odor causing bacteria (Benn, Nanoparticle Silver Released into Water from Commercially Available Sock Fabrics 2008). These impregnated socks however have been shown to release large amounts of n-Ag particles when washing. These free nanoparticles easily enter wastewater collection systems. The microbial inhibitory effects of nanosilver were evaluated by studying the effects Escherichia coli (E. coli) growth under nanosilver presence. Results showed that E. coli bacterial growth was inhibited when nanosilver was introduced. This may have detrimental impacts on aerobic wastewater treatment systems which rely on bacteria to break down organic material. Systems may become inefficient and obsolete with an increasing prevalence of nanosilver in sewage.
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Date Issued: 2012
Identifier: FSU_migr_uhm-0068
Format: Thesis

Title: Relationships of Geomorphic Conditions and Woody Materials in Coastal Plain Streams.
Creator: Morris, Cameron, Hilton, Amy Chan, Clark, Clayton, Watts, Michael, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Streams of the coastal plain were inventoried and surveyed for large woody material (LWM) in relationship with fluvial geomorphic characteristics. This empirical data was used to identify wood density based on stream channel hydraulic geometry (i.e., width, depth, and cross sectional area) and the relationship to bankfull discharge and watershed area. Drainage area and stream bankfull width were determined to be correlated with total volume and number of pieces of LWM, providing predictive...
Show moreStreams of the coastal plain were inventoried and surveyed for large woody material (LWM) in relationship with fluvial geomorphic characteristics. This empirical data was used to identify wood density based on stream channel hydraulic geometry (i.e., width, depth, and cross sectional area) and the relationship to bankfull discharge and watershed area. Drainage area and stream bankfull width were determined to be correlated with total volume and number of pieces of LWM, providing predictive capability for the natural abundance of LWM in streams of the coastal plain. Following its restoration, Anderson Branch was inventoried for in-stream LWM and monitored for stability. Minimal variability observed in the dimension, pattern, and profile of the stream channel was attributed to the proper placement and density of LWM. Streams of the coastal plain were also surveyed for the contribution of sandbed formations and woody material to channel roughness. The protrusion height of sandbed formations and woody material were determined to be a better estimate of Manning's n than bed material size, providing improved guidance in restoration practices as well as a more accurate method of predicting bankfull discharge in the event a gage/and or regional curve is unavailable.
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Date Issued: 2012
Identifier: FSU_migr_etd-5411
Format: Thesis

Title: An Assessement of on-Site Renewable Energy Source Consideration with Original Building Construction Procurement Efforts.
Creator: Sneed, Troy Lenard, Clark, Clayton J., AbdelRazig, Yassir, Sobanjo, John, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: As energy resources are needed in abundance to sustain the ever evolving global economy, the world's energy dependency for good reason, is beginning to shift. Various studies have shown that although fossil fuels are still the primary source of energy for the world, the utilization of more sustainable energy resources is on the rise. However due to current competitive bidding strategies and underlying practices that typically consider sustainable features such as renewable energy sources as...
Show moreAs energy resources are needed in abundance to sustain the ever evolving global economy, the world's energy dependency for good reason, is beginning to shift. Various studies have shown that although fossil fuels are still the primary source of energy for the world, the utilization of more sustainable energy resources is on the rise. However due to current competitive bidding strategies and underlying practices that typically consider sustainable features such as renewable energy sources as costly additions rather than effective options to program requirements, building construction procurement strategies have been slow to embrace this change. In this thesis, a methodology is derived for assessing the overall benefits of utilizing a renewable energy source as a program option from the original building construction procurement effort. This methodology was developed by utilizing project procurement methods and techniques, in addition to certain life cycle costing concepts. Data from the original procurement of The Basic School in Quantico, Virginia was used to apply this methodology. The results of this application and supplemental research show that the incorporation of a renewable energy source into the original building construction procurement effort as opposed to additions that are incorporated later in the project procurement effort produced cost and schedule benefits. Furthermore, a contractor could apply this methodology to similar projects that incorporate sustainable features into its original design and cost estimates, and utilize the findings of the application in the technical components of future projects.
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Date Issued: 2012
Identifier: FSU_migr_etd-5437
Format: Thesis

$Ozone Pre-Treatment to Enhance Anaerobic Degradation of Refractory Landfill Leachate Organics$

Title: Ozone Pre-Treatment to Enhance Anaerobic Degradation of Refractory Landfill Leachate Organics.
Creator: Qiao, Yu, Watts, Michael, Chen, Gang, Hilton, Amy Chan, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Advanced oxidation processes (AOPs) have garnered recent consideration as an option to reduce organic loading, and the recalcitrance of mature landfill leachate. Hydroxyl radicals (*OH) are produced during AOPs, which are effective in destroying organic chemicals. To investigate the potential for leachate conditioning by pre-ozonation treatment (O3/H2O2 and O3), low-mg/L level ozone stock solutions were spiked into an `old' landfill leachate (0 to 7.5mg/L O3). The stoichiometric ratio of 1.1...
Show moreAdvanced oxidation processes (AOPs) have garnered recent consideration as an option to reduce organic loading, and the recalcitrance of mature landfill leachate. Hydroxyl radicals (*OH) are produced during AOPs, which are effective in destroying organic chemicals. To investigate the potential for leachate conditioning by pre-ozonation treatment (O3/H2O2 and O3), low-mg/L level ozone stock solutions were spiked into an `old' landfill leachate (0 to 7.5mg/L O3). The stoichiometric ratio of 1.1:1 was determined to be the optimal molar ratio of O3 to H2O2 based on the biodegradability of the leachate organics. The leachate conditioning includes: measurement of the three anthropogenic contaminants tris-(2-chloroethyl) phosphate (TCEP), tris-(butoxyethyl)-phosphate (TBEP) and 17ß-estradiol (E2) by pre-ozonation treatment and the pre-ozonation followed by anaerobic treatment; COD and BOD5/COD analysis of the ozonated leachate; measurement of the methane and total gas formation during the anaerobic incubation; also the COD analysis of the mixed leachate and sludge solution during the anaerobic incubation. When treating with O3 and O3/H2O2 pre-oxidation, the removal of E2 was 65% at the ozone dose of 4.5mg/L to 5.4mg/L, which was higher than that of TCEP and TBEP. Based on one-way ANOVA analysis, the O3/H2O2 pre-treatment was observed to have significantly improved degradation of E2 during anaerobic incubation of oxidized leachates (removal rate of E2 was 53.7% after 15 days of incubation). However, O3 pre-treatment improved post-ozone degradation of TCEP and TBEP by 26% and 39.3% as compared with O3/H2O2 after 15 days of incubation. In addition, overall anaerobic activity was not impacted by the applied ozone pre-treatments, as measured by methane formation, total gas formation, and COD removal. In general, low-mg/L ozone pre-treatment, prior to anaerobic incubation, was found to improve biological degradation
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Date Issued: 2012
Identifier: FSU_migr_etd-5421
Format: Thesis

Title: Analysis of Cost Change in Air Force Construction Projects from Planning to Completion.
Creator: Barnes, Robert J., Sobanjo, John O., Abdelrazig, Yassir, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Construction is a major industry in the United States. In 2010, over $506 billion was spent in construction and construction-related activity, amounting to over 3.4% of Gross Domestic Product (GDP). $21.2 billion, or 0.6% of federal outlays for 2010 was spent on military construction. This accounts for nearly 4% of total construction annually. This study examined three variables in the life of an Air Force military construction (MILCON) project: the programmed amount (PA), the contract award ...
Show moreConstruction is a major industry in the United States. In 2010, over $506 billion was spent in construction and construction-related activity, amounting to over 3.4% of Gross Domestic Product (GDP). $21.2 billion, or 0.6% of federal outlays for 2010 was spent on military construction. This accounts for nearly 4% of total construction annually. This study examined three variables in the life of an Air Force military construction (MILCON) project: the programmed amount (PA), the contract award (CA), and the final current working estimate (CWE). These variables, respectively, reflect the initial planning budget (PA), the actual contractor's estimate and bid (CA), and the final, actual cost of the project to the Air Force (CWE). Statistical hypothesis tests showed there is an appreciable difference between each variable. Generally speaking, the PA is higher than the CA, but the CWE approaches the PA at end of the project. The study suggests several reasons for this, including contractor estimate errors or "bad faith", non-inclusion of inflation, and initial estimate inaccuracy. The results of this study can be used to better analyze contractors' bids as well as initial budgetary estimates to get a more accurate picture of the cost of a particular MILCON project.
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Date Issued: 2012
Identifier: FSU_migr_etd-5317
Format: Thesis

Title: Correlation of Water Quality Indicators for Coastal Marshes.
Creator: Hendrix, Matthew, Chen, Gang, Watts, Michael, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Florida provides some of the most diverse and beautiful environments in the United States, with northwest Florida being a nearly undisturbed bounty of lush lands, springs, and other geological and ecological features. Increases in population have recently started to jeopardize some of Florida's prized areas, including the Ochlocknee-St Marks Basins. Development and agriculture has started to affect watersheds and waterbodies. This study has evaluated the water quality of coastal marshes at...
Show moreFlorida provides some of the most diverse and beautiful environments in the United States, with northwest Florida being a nearly undisturbed bounty of lush lands, springs, and other geological and ecological features. Increases in population have recently started to jeopardize some of Florida's prized areas, including the Ochlocknee-St Marks Basins. Development and agriculture has started to affect watersheds and waterbodies. This study has evaluated the water quality of coastal marshes at the St. Marks national Wildlife Refuge in terms of coliform and chlorophyll a. With these constituents, dissolved oxygen (DO), temperature, pH, conductivity, and total suspended solids were evaluated. The study took place with data from January 2009 to June 2009. The study site of this research, St. Marks National Wildlife Refuge, is located 25 miles south of Tallahassee along the Gulf Coast of Florida. To analyze for coliform, 100ml samples were filtered on cellulose nitrate membranes and subsequently incubated. After 24hrs the fecal coli forms were counted and recorded. Measuring the chlorophyll a was done taking a volume of water from a particular depth and filtering it through a fine glass fiber filter to collect all of the particulate material great than 1 micron. To extract the chlorophyll, acetone/alcohol was used as a solvent and then measured using an optical kit and Luminometer utilizing a chlorophyll a standard. Effective diffusion was then measured in the lab using a diffusion coefficient in distilled water. This process was also observed using a Hamamatsu high sensitivity monochrome digital camera in a dark room, with the sample being placed in a petri dish with native soil. Chlorophyll a adsorption was measured by introducing the sample to a column filled with goethite-coated silica sand. Transport parameters were obtained by fitting the experimentally obtained Chlorophyll a breakthrough data using an implicit, finite-difference scheme. All the parameters were optimized by minimizing the sum of squared differences between observed and fitted concentrations using the nonlinear least-square method. Some key observations over the sample period include the dropping of DO as the summer months began indicating increased microbial activity with temperature. TKN and Chlorophyll were observed to increase as temperature increased. When observing Chlorophyll as a function of TKN, the Pearson Correlation and the plot indicate that with increased TKN more microbiological activity occurs - such as with plants, algae, etc. Interestingly when Chlorophyll was plotted as a function of DO, the low DO encourages microbial growth, however only to an extent. The point can be made that less polluted water has less microbial activity. The correlation between coliform and turbidity showed an increase of coliform with NTU. Chlorophyll as a function of turbidity showed no correlation. However as a first order function, d[Chlorophyll a]/d[Turbidity] displayed a linear relationship with turbidity, indicating the correlation of chlorophyll a variation with respect to turbidity. When conductivity was plotted against pH, the variability of conductivity and pH was not significantly different. Chlorophyll a also had a correlation with pH. With the increase of pH, chlorophyll a exponentially decreased. This research shows the increased ability to forecast and assess risk presented by development and agriculture of coastal environment based on physical and chemical variations in coastal wetland ecosystems.
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Date Issued: 2012
Identifier: FSU_migr_etd-5361
Format: Thesis

Title: Colloid and Surfactant Transport Modeling Through Agricultural Soil.
Creator: Patil, Sandip R. (Sandip Raman), Chen, Gang, Ordóñez, Juan Carlos, Clark, Clayton, Watts, Michael, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: National Water-Quality Assessment Program (NAWQA) was designed just after the U.S. Geological was established. The primary objective of the NAWQA was to understand the key processes controlling contaminant fate and transport into the Nation's water resources. In particular, wide use of pesticides and fertilizers in agricultural field can impact on the quality of surface and ground waters. Contaminants can be carried to the water bodies by several ways. In colloid-facilitated transport process...
Show moreNational Water-Quality Assessment Program (NAWQA) was designed just after the U.S. Geological was established. The primary objective of the NAWQA was to understand the key processes controlling contaminant fate and transport into the Nation's water resources. In particular, wide use of pesticides and fertilizers in agricultural field can impact on the quality of surface and ground waters. Contaminants can be carried to the water bodies by several ways. In colloid-facilitated transport process colloidal particles serves as a transport media for the contaminants. Colloid release from the agricultural soil under unsaturated conditions is controlled by the hydrodynamic force, capillary force and electrostatic force that is determined by the solution chemistry in terms of solution ionic strength and pH. In this research, colloid release from the agricultural soil was investigated using an intact soil column collected from an agricultural site in Gadsden County of Florida. Colloid release was monitored and the colloid release curve was simulated using an implicit, finite-difference scheme to obtain the colloid release coefficient. It was found that the hydrodynamic force and electrostatic force overcame the capillary force under the experimental conditions of this research and consequently, colloids were released. For the colloid release, solution chemistry played a key role by controlling the colloid repulsive electrostatic force within the pore system. Colloid release exponentially decreased with the increase of solution ionic strength and increased with the increase of solution pH. Colloid release was finally found to be correlated to the colloid repulsive electrostatic force within the pore system, i.e., the greater the repulsive electrostatic force, more colloids were released. In situ colloid mobilization and transport has been studied under both saturated and unsaturated conditions. In saturated conditions, the controlling parameters are solution ionic strength and pH. Colloid mobilization and transport have been modeled by the advection-dispersion equation with a first-order colloid release. The inverse version of these models can provide a platform to estimate transport parameters based on transport observations. In this research, we taken the advantages of existing contaminants transport models by fully utilizing them to investigate colloid interactions with the surrounding environment and provide parameter constraints for colloid transport modeling applications under saturated conditions. In natural systems, colloids present a potential health risk due to their propensity to associate with contaminants or in the case of certain biological colloids, inherent pathogenic nature. Although colloidal interactions have been studied for many years and much has been learned about the physical and chemical processes that control colloid retention, there still remains significant uncertainty about the processes that govern colloid release. The aim of this study was to investigate the release of in situ colloids as a function of soil depth. Colloid release from intact agricultural soil columns with variable length was investigated. Colloid release curves were simulated using an implicit, finite-difference scheme and colloid release rate coefficient was found to be an exponential function of the soil depth. The simulated results demonstrated that transport parameters were not consistent along the depth of the soil profile. Wetting agents wet hydrophobic soil by lowering the cohesive and/or adhesive surface tension, which allows the water to spread out more evenly and allows for better penetration into the hydrophobic soils. While enhancing water penetration, wetting agent applications may bring adverse impact on the soil and groundwater at the same time. The residual organic phase in the soil pores poses a long-term source of groundwater contamination. After use, residual wetting agents and their degradation products are discharged to groundwater or directly to surface waters, then dispersed into different environmental compartments. In order to assess their environmental risks, we need to understand the distribution, behavior, fate and biological effects of these surfactants in the environment. This research was designed to investigate the application of nonionic wetting agents in agricultural soils. Performance of nonionic surfactants in intact soil columns collected from agricultural soils was explored and related to the soil and wetting agent properties. In addition, the impact of the organic concentration of wetting agent fate and transport was investigated. The transport of wetting agents in the agricultural soil columns was simulated using the proposed transport models and subsequently, the effect of organic compounds on wetting agent transport was quantified.
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Date Issued: 2012
Identifier: FSU_migr_etd-5098
Format: Thesis

Title: Risk Assessment of Florida's Coastal Bridges Exposed to Hurricane-Induced Storm Surge Wave Forces.
Creator: Stanford, Scott Steven, Sobanjo, John, Rambo-Roddenberry, Michelle, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The purpose and focus of this research was on studying the hazard to Florida's coastal bridges from storm surge induced wave forces inflicted on the bridges during hurricanes. It has been observed in recent years that bridges located in the coastal environment are vulnerable to deck unseating during the applied loading of storm surge wave forces. The goal of the research is to use modern and up-to-date analysis methods to address the risk and vulnerability of coastal bridges to being damaged...
Show moreThe purpose and focus of this research was on studying the hazard to Florida's coastal bridges from storm surge induced wave forces inflicted on the bridges during hurricanes. It has been observed in recent years that bridges located in the coastal environment are vulnerable to deck unseating during the applied loading of storm surge wave forces. The goal of the research is to use modern and up-to-date analysis methods to address the risk and vulnerability of coastal bridges to being damaged from storm surges during hurricanes along Florida's coastline. Implementing the current analysis methods will be useful for determining the magnitude of wave parameters and coinciding wave forces imposed on structural elements of a bridge superstructure. It is also the intention of this manuscript to address the need for an analysis of the entire network of Florida's coastal bridges, not just one specific bridge case study. This has been regarded as one of the largest limitations of current analysis in this field of work. This research provides an improved understanding of addressing bridge vulnerability from hurricane hazards on both local and network level as well as providing further insight into preventing and limiting the amount of damage that can occur during the event of a major hurricane making landfall.
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Date Issued: 2012
Identifier: FSU_migr_etd-5200
Format: Thesis

Title: Prefabricated Bridge Elements and Systems for off-System Bridges.
Creator: Servos, Joseph, Roddenberry, Michelle, Sobanjo, John, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Federal Highway Administration's (FHWA) ``Every Day Counts'' initiative aims to shorten the overall project delivery time, enhance safety, and protect the environment both on and around construction projects. Using innovative planning, design, and construction methods, Accelerated Bridge Construction (ABC) techniques reduce on-site construction time for new or replacement bridges. One aspect of ABC is Prefabricated Bridge Elements and Systems (PBES), where bridge components are fabricated...
Show moreThe Federal Highway Administration's (FHWA) ``Every Day Counts'' initiative aims to shorten the overall project delivery time, enhance safety, and protect the environment both on and around construction projects. Using innovative planning, design, and construction methods, Accelerated Bridge Construction (ABC) techniques reduce on-site construction time for new or replacement bridges. One aspect of ABC is Prefabricated Bridge Elements and Systems (PBES), where bridge components are fabricated offsite to reduce on-site construction activities. Many state departments of transportation, including Florida DOT, are currently making efforts to implement PBES for their bridge construction projects. The purpose of this research project was to investigate other statesÕ standards and to evaluate them for possible implementation in Florida. An exhaustive search was made, and new literature was reviewed, to learn about current DOT standards and practices. The search revealed that the states with the most prefabricated bridge standards or activities are as follows: Utah, Alabama, Texas, Minnesota, and a collaboration of Northeastern states. These standards were reviewed for details such as the presence of post-tensioning, joint types, design load, and inspectability. The three standard bridge types that show the most promise for adoption by FDOT are: Florida DOT District 2Õs Truncated ``Florida I-Beam'' (FIB), MinnesotaÔs Inverted Tee Beam, and PCI's ``Northeastern Extreme Tee'' (NEXT) Beam. A summary of the findings, including advantages and disadvantages of the bridge systems, is included in this report. Also included is a comprehensive list of web links to standard drawings from all state DOTs, which could also be helpful to expedite other research that involves standards and bridge construction/design practices.
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Date Issued: 2012
Identifier: FSU_migr_etd-5173
Format: Thesis

Title: The Potential Reduction of Combined Endocrine Disrupting Compounds in Zero-Valent Iron.
Creator: Pipkin, Leslie M., Clark, Clayton, Chen, Gang, Watts, Michael, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The research is focused on the degradation of two endocrine disrupting compounds (EDCs) in zero-valent iron. The endocrine disrupting compounds bisphenol A (BPA) and 17b-estradiol (E2) are chemical compounds that have an adverse effect on the environment, humans, and wildlife. These two chemical constituents are being examined in this research because they are still being used today and continue to impact their surrounding environment. These chemicals are considered persistent,...
Show moreThe research is focused on the degradation of two endocrine disrupting compounds (EDCs) in zero-valent iron. The endocrine disrupting compounds bisphenol A (BPA) and 17b-estradiol (E2) are chemical compounds that have an adverse effect on the environment, humans, and wildlife. These two chemical constituents are being examined in this research because they are still being used today and continue to impact their surrounding environment. These chemicals are considered persistent, bioaccumulative, and toxic to the environment. The research explores the technological use of zero-valent iron to degrade the chemical constituents in aqueous form. The study conducted laboratory batch experiments to compare the efficiency of using zero-valent iron in a reducing environment to remediate endocrine disrupting compounds in groundwater. The experimentations looked at varying ratios of volume of solution to mass of zero-valent iron. Furthermore, this study compared the reactions of the chemical constituent in question by varying the aqueous solution to entail the combined constituents (BPA and E2) to separate solutions to determine the chemical degradation model and rates over a period of a week. During the experiments held out with the combined concentration of BPA and E2, both BPA and E2 followed a power-law model. Degradation rates increased as the varying volume to mass ratio decreased. The higher degradation rates were found with a volume to mass solution at 2:1 which gave the chemicals the shortest half-lives. BPA's lowest calculated half-life was approximately 12 days. E2's lowest calculated half-life was approximately 1 day. The degradation rates varied for each EDC when the compounds were treated separately in an aqueous solution over a 24-hour period. The set of experimentations showed that the higher degradation rates occurred with a volume to mass ratio of 2:1. BPA followed the first-order degradation model and showed a reduction of approximately 93% with a calculated half-life of 24 days. E2 followed a pseudo first-order degradation model and showed a reduction of approximately 92% during a 24-hour period with a calculated half-life of 2.655 hours. The research shows that the chemicals are competing for the surface area of the iron when in combined solutions. The experimentations in separate solutions show that E2 is a limiting factor in the ZVI. The research determined that degradation of bisphenol A and 17b-estradiol will occur in an aqueous solution in zero-valent iron.
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Date Issued: 2012
Identifier: FSU_migr_etd-5112
Format: Thesis

Title: Effects of Secondary Elements and Joints on Strain Distribution in Composite Steel Girder Bridges.
Creator: Lewis, Michael, Tawfiq, Kamal, Rambo-Roddenberry, Michelle, Jung, Sungmoon, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: When considering the design of bridge girders, the American Association of State Highway and Transportation Officials (AASHTO) determine how the loads will be transferred to each girder. The equations used in AASHTO Load and Resistance Factor Design (LRFD) neglect the inertia added from secondary elements such as barriers and curbs. By neglecting these added effects, many bridges that are already built could have more strength than initially designed for. If the effects of these secondary...
Show moreWhen considering the design of bridge girders, the American Association of State Highway and Transportation Officials (AASHTO) determine how the loads will be transferred to each girder. The equations used in AASHTO Load and Resistance Factor Design (LRFD) neglect the inertia added from secondary elements such as barriers and curbs. By neglecting these added effects, many bridges that are already built could have more strength than initially designed for. If the effects of these secondary elements were considered, it would be possible to reduce the distribution factors that are given for interior and exterior girders. The bridge of concern for this project has four spans and was built in the early 1950s. Some repair work and modifications were conducted on the bridge and a load test was performed a week afterwards. The tests were done to find out if the repairs were adequate based on full composite action between the girders and the slab. During this initial test, some problems were discovered in one of the interior spans. This interior span is unique because it contains an expansion joint and a physical barrier and curb joint at the mid-span of the bridge. After problems were discovered, the physical joints were recommended to be grouted and a second load test was conducted afterwards. The second load test yielded much lower strains in the exterior girders due to the decrease in localized stress at the physical joint. In order to prove that filling the joint could improve the bridges strength, a finite element model was constructed to simulate this activity. Two models were made, one prior to filling the physical barrier and curb joints and one after. The test data was compared to the data from the finite element model to ensure accuracy. After the model was calibrated, the secondary members of the bridge were modified to study their effects. The primary goal of this research is to prove that a physical joint in a continuous exterior secondary element will cause the same amount of strain at its location as if they weren't there to begin with. By analyzing the finite element model data, it was found that when the joint is filled the behavior of the bridge changes and the exterior girder has up to 50% reduction in strain. The effect of concrete cracking and stress distribution that is associated with it is a secondary topic that was discussed because it was a driving factor in the model calibration.
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Date Issued: 2012
Identifier: FSU_migr_etd-4986
Format: Thesis

Title: Mitigation of Vortex-Induced Vibrations in Cables Using Macro-Fiber Composites.
Creator: Munoz, Gustavo J., Jung, Sungmoon, Rambo-Roddenberry, Michelle, Spainhour, Lisa K., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Vortex-Induced Vibration (VIV) in cables is a prevalent phenomenon affecting the structural health of bridges and their components. Past studies have shown both passive and active methods are beneficial in the reduction of vibrations, however, a number of issues such as excessive base moment, transformation of geometry, intrusive implementation and fatigue limit the effectiveness of current engineering. A method involving no intrusion, no geometrical manipulation and a mechanism to prevent...
Show moreVortex-Induced Vibration (VIV) in cables is a prevalent phenomenon affecting the structural health of bridges and their components. Past studies have shown both passive and active methods are beneficial in the reduction of vibrations, however, a number of issues such as excessive base moment, transformation of geometry, intrusive implementation and fatigue limit the effectiveness of current engineering. A method involving no intrusion, no geometrical manipulation and a mechanism to prevent and mitigate VIV is needed. A "skin" of material embedded with Macro-Fiber Composite (MFC) material and with the capabilities of perturbing the surface near the separation point of vortex shedding is explored and tested. Simplifications of the proposed material are made in order to understand the effects of the capabilities of a perturbing skin of MFC material. Construction of a 17-ft Open-circuit wind tunnel is done in order to make the VIV condition to be tested with the near method of VIV control. The VIV on cables is recorded. Experiments are run inside the tunnel at a Re of 11400 and 6400. In order to see the effects of surface perturbations, an MFC actuation mechanism is made and a cable section effectively able to cause surface perturbations is built. A test is then run to find the effect of different angles of perturbation. Finally, a testing and analysis of a phase-difference of a signal, at prescribed perturbation frequencies is done. This is analyzed against surface vortex formation theory. The data are analyzed in order to see the capabilities of an MFC skin on VIV of cables. The mechanism shows promise in both reducing VIV and providing for a low-key, non-intrusive control mechanism.
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Date Issued: 2012
Identifier: FSU_migr_etd-5058
Format: Thesis

Title: Developing Crash Modification Factors for Urban Highway with Substandard Wide Curb Lane.
Creator: Mbatta, Geophrey, Moses, Ren, Niu, Xufeng, Sobanjo, John, AbdelRazig, Yassir, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Across the United States, a great deal of attention is being focused on promoting energy efficient and environmental friendly modes of transportation. Bicycling is an integral part of a sustainable transportation system that is one of the most efficient. The growing use of bicycles for commuting and leisure activities is creating conflicts with motorized traffic mainly due to deficient roadway facilities that were in the past designed to primarily accommodate motorized traffic.In 2008, 716...
Show moreAcross the United States, a great deal of attention is being focused on promoting energy efficient and environmental friendly modes of transportation. Bicycling is an integral part of a sustainable transportation system that is one of the most efficient. The growing use of bicycles for commuting and leisure activities is creating conflicts with motorized traffic mainly due to deficient roadway facilities that were in the past designed to primarily accommodate motorized traffic.In 2008, 716 bicyclists were killed in the USA which corresponds to 2 percent of total traffic fatalities reported. In the same year, over 52,000 bicyclists were also reported to have been injured in traffic crashes. When the data is broken down state by state, Florida ranked second with 6.82 bicyclist fatalities per million population. These statistics provide a grim reminder of the dangers faced by bicyclist riding on urban and rural highways.This study developed lane width crash modification factors (CMFs) for roads with wider outside lane narrower or equal to 14 ft, and inside lanes narrower or equal to 11 ft that were minimum recommended by the Florida Department of Transportation (FDOT) for arterial roadways in the state of Florida. The road segments used were urban four-lane with a divided median and four-lane two-way left turn lane (TWLT). Data used in the evaluation included 25 centerline miles of urban four-lane (TWLT) roads and 75 centerline miles of four-lane with a divided median roads. Two main types of crash modification factors and safety performance functions were developed in this study. The first type is crash modification factors and safety performance functions for all types of crashes, and the second is crash modification factors and safety performance functions for motor vehicle-bicyclist crashes only.In sum the results obtained from this study suggest that, maintaining of inside lane width to 11.5ft and outside lane width to 13 ft for 4D and 5T could results in less number of all types of crashes. Additionally, the decreases in motor vehicle-bicyclist crashes will also be achieved by outside lane width of 13 ft as the inside lane width was not found to contribute to the increase or decrease in motor vehicle-bicyclist crashes.
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Date Issued: 2011
Identifier: FSU_migr_etd-2627
Format: Thesis

Title: Feasibility Study, Primary Designs and Development of Alternative Evapotranspiration Covers for Landfills and Waste Dump Sites in Tropical Locations.
Creator: Escobar, Francisco Jose, Abichou, Tarek, Cheng, Gang, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: People generate a large and ever-increasing volume of waste, which originates in rural and urban areas, industrial operations and other activities. In spite of waste recycling, which is the solution to the huge amount of solid waste, a large part of it is deposited into landfills, dumps, etc.Landfills are, at present, the most widely used waste disposal facilities. Final cover systems are used at landfills and other types of waste disposal sites to control moisture and percolation, promote...
Show morePeople generate a large and ever-increasing volume of waste, which originates in rural and urban areas, industrial operations and other activities. In spite of waste recycling, which is the solution to the huge amount of solid waste, a large part of it is deposited into landfills, dumps, etc.Landfills are, at present, the most widely used waste disposal facilities. Final cover systems are used at landfills and other types of waste disposal sites to control moisture and percolation, promote surface water runoff, and minimize erosion. In addition, covers prevent direct exposure to the waste, control gas emissions and odors, prevent occurrence of disease vectors and other nuisances, and meet aesthetic and other end-use purposes. The Resource Conservation and Recovery Act (RCRA) Subtitle D, requires the use of landfill covers to meet these needs.Prescribed covers, permitted by current regulations, are based on a barrier concept that requires them to employ resistive principles, i.e., a layer having low saturated hydraulic conductivity. The most important focus of this study, is the EvapoTranspiration cover (ET) concept, which utilizes one or more vegetated soil layers to retain water until it is either transpired through vegetation, or evaporated from the soil surface. These cover systems rely on the water storage capacity of the soil layer, rather than low hydraulic conductivity materials, to minimize percolation. ET cover designs are based on using the hydrological processes and water balance components at a specific site, which includes the water storage capacity of the soil, precipitation, surface runoff, evapotranspiration and infiltration. The objective of this study is to determine the feasibility of developing and using ET Covers in tropical locations with medium to high precipitation. Puerto Rico can be assimilated as a part and sample of the typical average "Tropical Zones," so the study was concentrated there. The obtained conclusions can be applied later, along with the same principles, to Tropical Zones in general, which will have similar characteristics of rainfall, vegetation, soil texture and classification, and temperature. The study consisted of collecting climate, soil, and vegetation data and characteristics from six regions or "Ecozones" determined on the Island of Puerto Rico, as a representative of the "Tropical Sub-climate." The collected data was then used as input of a software called PR-ET to calculate the PET or ETo of the location and then the basis data of a flow model (HYDRUS 1-D) to simulate infiltration into the waste during peak weather events. PET and ETo are similar terms and are defined as the "Potential Evapotranspiration." Simulations were performed to evaluate the effect of the weather period, the effect of soil thickness, the effect of vegetation, the LAI (Leaf Area Index) and finally to determine what regions in Puerto Rico show potential for implementing ET covers.Results from this study showed some sub-regions (or locations) belonging to the six Ecozones (or regions) of Puerto Rico were able to meet the preliminary requirements for hydrological performance as required by the RCRA. However, field evaluation of these designs should be performed before full implementation of ET covers in these regions. Of the 21 locations studied in the preliminary design, 15 were adequate for study by modeling them to confirm the feasibility of using the Evapotranspiration covers in them. After this modeling or simulation was conducted, the results were as follows: eight locations can effectively use ET covers using as covering vegetation pastures. Five locations can use ET covers, but the vegetation needs to be changed using then shrubs and grass. The other locations are being rejected for this study. The selected locations are supposed to have thickness less than 2.0 m.
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Date Issued: 2011
Identifier: FSU_migr_etd-0523
Format: Thesis

Title: Microbial Transport and the Use of Microbial Fuel Cell Technology to Prevent Iron Release in Landfills Nearby Northwest Florida.
Creator: Subramaniam, Pawan Kumar, Chen, Gang, Ordóñez, Juan Carlos, Huang, Wenrui, Watts, Michael, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Microbial transport plays an essential role in microbial activities in the subsurface soil. In this research, transport of Echerichia coli, Pseudomonas fluorescens and Bacillus subtilis in silica sand under water unsaturated conditions was investigated using column experiments and a two-region solute transport model was used to simulate the bacterial transport with an assumption that bacterial deposition occurred within the immobile region only. It was concluded from this research that...
Show moreMicrobial transport plays an essential role in microbial activities in the subsurface soil. In this research, transport of Echerichia coli, Pseudomonas fluorescens and Bacillus subtilis in silica sand under water unsaturated conditions was investigated using column experiments and a two-region solute transport model was used to simulate the bacterial transport with an assumption that bacterial deposition occurred within the immobile region only. It was concluded from this research that bacterial retention in unsaturated porous media was determined by their interactions within the system, which could be predicted based on independently determined surface properties. Following this research, I further investigated the activities of Shewanella putrefaciens in reducing iron oxide in the iron rich soil of Northwest Florida with landfill leachate serving as the carbon source. In addition, adsorption of reduced ferrous iron on S. putrefaciens was characterized. Considering that organic compounds can be potentially served as energy source, I explored the feasibility of the usage of microbial fuel cell (MFC) technology for landfill leachate decomposition and power generation. Landfill leachate collected from landfills located in Northwest Florida was tested in a laboratory scale MFC to provide evidence that landfill leachate can be decomposed and electrons released from leachate decomposition in the anodic chamber can be transported and consumed in the cathodic chamber and consequently, electricity can be generated. Finally, I studied the interactions of bacteria with the porous media to explain microbial biofouling.
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Date Issued: 2011
Identifier: FSU_migr_etd-1517
Format: Thesis

Title: Stochastic Preservation Model for Transportation Infrastructure.
Creator: Thomas, Omar St. Aubyn Alexander, Sobanjo, John, Chicken, Eric, Spainhour, Lisa, Mtenga, Primus, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: In this dissertation new methodologies were developed to address some of the existing needs as it relates to Transportation Asset Management Systems (TAMS). The goal of TAMS is to model the performance and preservation of transportation infrastructure. Currently, traditional Bridge Management Systems (BMS) such as Pontis® and BRIDGIT® utilize Markov chain processes in their performance and preservation models. Markov models have also been suggested and used at some State transportation...
Show moreIn this dissertation new methodologies were developed to address some of the existing needs as it relates to Transportation Asset Management Systems (TAMS). The goal of TAMS is to model the performance and preservation of transportation infrastructure. Currently, traditional Bridge Management Systems (BMS) such as Pontis® and BRIDGIT® utilize Markov chain processes in their performance and preservation models. Markov models have also been suggested and used at some State transportation agencies for modeling the performance of highway pavement structures. The Markov property may be considered restrictive when modeling the deterioration of transportation assets, primarily because of the "memoryless" property. In other words, the Markov property assumes that the sojourn times in the condition states follows an exponential distribution for the continuous-time Markov chain, and a geometric distribution for the discrete-time Markov chain. This research addresses some of the limitations that arise from the use of purely Markov chain deterioration and performance models for transportation infrastructure, by introducing alternative approaches that are based on the semi-Markov process and reliability functions. The research outlines in detail an approach to develop semi-Markov deterioration models for flexible highway pavements and American Association of State Highway Transportation Officials (AASHTO) Commonly Recognized (CoRe) Bridge Elements. This takes into consideration the probability of transitions between condition states and the sojourn time in a particular condition state before transitioning to another condition state. The proposed semi-Markov models are compared against the traditional Markov chain models. With Weibull distribution as the assumed distribution of the sojourn time in each condition state, for both the pavement and bridge deterioration models, Maximum Likelihood Estimation (MLE) was used to determine the estimates of the distribution parameters. For the pavement deterioration, the comparison of the semi-Markov and Markov chain models is presented, based on a Monte Carlo simulation of the condition. For the bridge element deterioration, the proposed semi-Markov model is compared against another semi-Markov approach outlined by Black et al. (2005a,b). A Bayesian-updated model was also compared to the proposed semi-Markov model. The research findings on the semi-Markov modeling validates the hypothesis that the rate of deterioration of pavements and bridge elements tends to increase over time. The results obtained from this study outlined a feasible alternative method in which historical condition data can be used to model the deterioration of pavement and bridge elements based on semi-Markov processes. For pavement deterioration, the semi-Markov model appeared to be superior to that of the Markov chain model in predicting the pavement conditions for the first five years subsequent to a major rehabilitation. The approach by Black et al. (2005a,b), which was applied to bridge element deterioration, assumes that the proportion of asset in state i at interval t is equal to the total probability of that asset being in state i after the t-th interval. It was discovered that this may not be true when the sample size of the asset being analyzed gets relatively small. Black et al. (2005a,b) used a least squares optimization technique to estimate the parameters of the (Weibull) sojourn time distribution, obtaining local optimal values, which may not best estimate the condition of the asset. An adaptive control approach for modeling the preservation of CoRe Bridge Elements based on Semi-Markov Decision Processes (SMDP) is also outlined in this dissertation. The methodology outlined in this study indicated that the use of SMDP can be used to determine the minimum long-term costs for the preservation of bridge elements from the CoRe Bridge Element data. The use of semi-Markov process to model deterioration relaxes the assumption of the distribution of the sojourn time between condition states for deterioration and improvement works, and therefore the SMDP model is less restrictive than Markov Decision Process (MDP) model. Also, Reliability (survival) functions were developed for both pavement segments and bridge elements to estimate their service lives. The Weibull regression and Cox Proportional Hazards models developed showed the association between factors, such as Average Daily Traffic (ADT) and the environment, and the condition of the asset over time. The proposed methodology outlined above is being researched at a time when there is a need for increased efficiency in the spending of government resources, while ensuring the preservation of the nation's transportation assets and network. The proposed stochastic models are based on the principles of semi-Markov processes, and address some of the limitations of the traditional Markov chain model. The survival analyses using the historical condition data allows for quick estimations as it relates to the service lives for bridge segments and bridge elements.
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Date Issued: 2011
Identifier: FSU_migr_etd-1564
Format: Thesis

Title: Mitigation Techniques for Aluminum Pool Enclosure Connections in High Wind Speeds.
Creator: Schellhammer, Michael Ryan, Jung, Sungmoon, Rambo-Roddenberry, Michelle, Wekezer, Jerry, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Aluminum pool enclosures consistently yield significant insurance losses due to damage suffered during hurricanes and strong windstorms. The damaged pool enclosures frequently produce airborne debris, which can often lead to additional damage on the host structure. For this reason, pool enclosures represent an important area of concern when it comes to mitigating overall structural damage caused by hurricanes and strong windstorms. Most commonly, a pool enclosure fails due to insufficient...
Show moreAluminum pool enclosures consistently yield significant insurance losses due to damage suffered during hurricanes and strong windstorms. The damaged pool enclosures frequently produce airborne debris, which can often lead to additional damage on the host structure. For this reason, pool enclosures represent an important area of concern when it comes to mitigating overall structural damage caused by hurricanes and strong windstorms. Most commonly, a pool enclosure fails due to insufficient connection performance. Insufficient connection performance generally consists of screw pullout and/or other hardware failures. Improving the function of these aluminum connections can help alleviate pool enclosure failure and thus lessen the amount of insurance losses accumulated. This research investigates different mitigation techniques involving the pool enclosure connection with the host structure. Due to the extensive variety of connection designs used by contractors across Florida, several connection specimens were tested and analyzed to provide the best performing and most cost efficient results. The connection components under investigation mainly included angle size, screw layout, and screw size. These components were monitored with the overall goal of optimizing the hardware combination. Each specimen was tested against windward and uplift forces using an MTS machine capable of delivering axial forces to the specimens. In addition to continuous loading, fatigue loading was utilized to examine connection behavior once the connection was compromised and a load is re-applied. Load and corresponding displacement values were recorded during testing to provide comparable strength capacities for each specimen. In order to determine the probability of connection failure, fragility curves were constructed and interpreted then applied to a financial analysis to achieve benefit-cost ratios. The resulting financial and performance benefits serve as benchmarks for optimal connection configuration. The conclusions obtained from testing will provide valuable information to pool enclosure designers and contractors who hope to get clarification on the ambiguous range of connections used throughout Florida. Since little tangible research has been conducted on pool enclosure connection strength the insight provided by this research could prove useful to the pool enclosure industry.
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Date Issued: 2011
Identifier: FSU_migr_etd-2021
Format: Thesis

Title: Sequential O3 Anaerobic Activated Sludge Treatment of Municipal Landfill Leachate.
Creator: Mumm, Andrés A. Lastra, Watts, Michael, Chen, Gang, Hilton, Amy Chan, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: In this study, laboratory experiments were conducted to compare the efficiency of using O3 and O3+H2O2 as precursor to anaerobic biological treatment of the treatment of landfill leachate. Both oxidation systems were proven efficient in increasing the overall biodegradability of the leachate. At an ozone dose of 7.5ppm biodegradability of the leachate was increased by 25%, while a combination of 7.5ppm of ozone with 5ppm of hydrogen peroxide resulted in a 35% increase in biodegradability of...
Show moreIn this study, laboratory experiments were conducted to compare the efficiency of using O3 and O3+H2O2 as precursor to anaerobic biological treatment of the treatment of landfill leachate. Both oxidation systems were proven efficient in increasing the overall biodegradability of the leachate. At an ozone dose of 7.5ppm biodegradability of the leachate was increased by 25%, while a combination of 7.5ppm of ozone with 5ppm of hydrogen peroxide resulted in a 35% increase in biodegradability of the treated leacahte. Furthermore, this study investigated the efficiency of using the mentioned oxidation processes for overall enhancement of landfill leachate water quality and the degradation of endocrine disrupting compounds (EDCs) present in the leachate. The research proved the studied oxidants were able to decrease overall total organic carbon (TOC) concentrations and were responsible for the removal of a fraction of the total ammonia concentration from the studied landfill leachate. Furthermore, the research showed that ozone and the peroxone process had the ability to degrade EDCs that were present in leachate. Second order rate constants for the degradation of EDCs both in water and in leachate were also calculated in this study. The leachate treated in the experiments was categorized as having high ammonia, high TOC concentration, low biodegradability and low UV transmittance. The impact of ammonia, carbonates and other oxidant scavengers on the overall efficiency of the oxidants was also investigated in this study.
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Date Issued: 2011
Identifier: FSU_migr_etd-3265
Format: Thesis

Title: Exploration of Monostrand Use in Segmental Box Girder Bridges.
Creator: Spear, Herbert Houston, Rambo-Roddenberry, Michelle, Spainhour, Lisa, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: For the past several decades the segmental box girder bridge has proven itself to be one of the more efficient bridge types. Using reusable form work, segments are match-cast, ensuring a more perfect connection during the construction phase. These benefits in conjunction with the fact that the costs of startup and form work are absorbed into the total cost of each segment mean that the longer the final bridge is, the less the cost is per segment, making the segmental box girder bridge one of...
Show moreFor the past several decades the segmental box girder bridge has proven itself to be one of the more efficient bridge types. Using reusable form work, segments are match-cast, ensuring a more perfect connection during the construction phase. These benefits in conjunction with the fact that the costs of startup and form work are absorbed into the total cost of each segment mean that the longer the final bridge is, the less the cost is per segment, making the segmental box girder bridge one of the most popular long bridge types constructed in the U.S. To minimize cost, it is important to design each segment for efficiency in terms of quantity of longitudinal and transverse post-tensioning and reinforcing steel. The inclusion of post-tensioning technology results in an overall compressive state in the longitudinal and transverse directions of the segments, improving structure strength and service life. However, despite the benefits inherent in using post-tensioning technology, the webs still contain standard deformed reinforcement. The goal of this research is to fit a greased and sheathed monostrand within a segment in a way that both webs and bottom flange would be placed in a state of compression, thereby reducing the demand for standard web reinforcement and, hopefully, segment cost. The research objectives include analyzing principal stresses in the webs of the segment, modifying the segment so as to restrain the monostrand within the webs, designing any additional reinforcement that may be necessary, and finally comparing the estimated construction cost of the new design with that of a pre-existing structure. The results from this research have shown that it is indeed possible to place a greased and sheathed monostrand within the webs of a segment with beneficial results and that the demand for standard deformed reinforcement will thus be reduced.
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Date Issued: 2010
Identifier: FSU_migr_etd-0375
Format: Thesis

Theses and Dissertations (138)	+ -
Undergraduate Honors Theses (1)	+ -

Civil engineering (132)	+ -
Chemical engineering (3)	+ -
Engineering (3)	+ -

text (139)	+ -
doctoral thesis (6)	+ -
master thesis (4)	+ -

Florida State University (138)	+ -
Department of Civil and Environmental Engineering (137)	+ -
Chen, Gang (35)	+ -
Spainhour, Lisa (27)	+ -
Abichou, Tarek (24)	+ -

Sobanjo, John (24)	+ -
Hilton, Amy Chan (21)	+ -
Rambo-Roddenberry, Michelle (20)	+ -
Huang, Wenrui (19)	+ -
Tawfiq, Kamal (18)	+ -
Sobanjo, John O. (17)	+ -
Jung, Sungmoon (14)	+ -
AbdelRazig, Yassir (11)	+ -
Moses, Ren (11)	+ -
Spainhour, Lisa K. (11)	+ -
Tang, Youneng (11)	+ -
Clark, Clayton (10)	+ -
Wekezer, Jerry (10)	+ -
Mtenga, Primus (9)	+ -
Watts, Michael (9)	+ -
Clark, Clayton J. (8)	+ -
Mtenga, Primus V. (8)	+ -
Mussa, Renatus (8)	+ -
Ping, Wei-Chou V. (7)	+ -
Dzurik, Andrew (6)	+ -
FAMU-FSU College of Engineering (6)	+ -
Leszczynska, Danuta (6)	+ -
Tawfiq, Kamal S. (6)	+ -
Abdullah, Makola (5)	+ -
Ahmad, Hafiz (5)	+ -

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