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(1 - 7 of 7)
- Title
- A Study of Differences in Vertical Phosporus Profiles Within the Sediments of Selected Florida Lakes as Related to Tropic Dynamics.
- Creator
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Stewart, Edgar Allen, Yousef, Yousef A., Engineering
- Abstract / Description
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Florida Technological University College of Engineering Thesis; Several Florida lakes with different documented trophic state indices were selected for sediment analysis. Vertical sections of the sediment were taken at depths of .1, .5 , 1, 2, 3, 4, 5, 6, 10 and l5 centimeters below the surface of the sediment-water interface. Total Phosphorus analysis was done on each section. The profile presented was then evaluated and was found that the profiles best fit the equation Y = X/ A + BX, where...
Show moreFlorida Technological University College of Engineering Thesis; Several Florida lakes with different documented trophic state indices were selected for sediment analysis. Vertical sections of the sediment were taken at depths of .1, .5 , 1, 2, 3, 4, 5, 6, 10 and l5 centimeters below the surface of the sediment-water interface. Total Phosphorus analysis was done on each section. The profile presented was then evaluated and was found that the profiles best fit the equation Y = X/ A + BX, where Y is the Phosphorus Concentration in ppm. and X is the sediment depth in cm. Correlation between the trophic state and the profiles characteristics are presented. A hypothesis as to how, the sediment profile changes as the lake experiences increased Phosphorus loading is presented, and is used to evaluate the lake studied. This discussion expresses phosphorus dynamics within the sediments in terms of adsorption, chemical changes, biological activity, and molecular and eddy diffusion.
Show less - Date Issued
- 1976
- Identifier
- CFR0003479, ucf:53024
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0003479
- Title
- ASSESSMENT OF AQUIFER STORAGE AND RECOVERY IMPACT ON PHOSPHORUS STABILITY IN LAKE SEDIMENT.
- Creator
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Liu, Sha, Chang, Ni-bin, University of Central Florida
- Abstract / Description
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Lake Okeechobee, the second largest natural freshwater lake in the United States, had experienced a historical drought in 2007-2008 and the inflow to Lake Okeechobee has been reduced by 40% of the average daily mean between warm phase and cold phase due to the impact of Atlantic Multidecadal Oscillation in the past six decades. To cope with this water resources management problem, the US Army Corps of Engineers (USACE) proposed the largest national implementation plan of aquifer storage and...
Show moreLake Okeechobee, the second largest natural freshwater lake in the United States, had experienced a historical drought in 2007-2008 and the inflow to Lake Okeechobee has been reduced by 40% of the average daily mean between warm phase and cold phase due to the impact of Atlantic Multidecadal Oscillation in the past six decades. To cope with this water resources management problem, the US Army Corps of Engineers (USACE) proposed the largest national implementation plan of aquifer storage and recovery (ASR) project in the Kissimmee River Basin. Routine operation of ASR will deliver recovered water from ASR wells into the lake with different water quality parameters resulting in some concerns about the phosphorus stability issues at the sediment bed, which may lead to eutrophication problems. To explore the potential impacts of ASR operation on phosphorus stability in terms of adsorption, desorption, and diffusion processes, this research presented a systematic assessment based on five different mixing ratios between ASR water and lake water, and explored the sensitivity with respect to the chemical equilibrium between lake water and ASR water to predict the phosphorus stability changes in lake sediment. A series of lab-scale batch and column tests in support of a mechanistic modeling analysis provided a holistic chemical assessment as to how the phosphorus stability may be influenced by different mixing ratios. It led to an observation that the ratio of 1:10 between ASR water and lake water proved to be an optical ratio to avoid eutrophication and bring ecological benefits based on a suite of criteria.
Show less - Date Issued
- 2010
- Identifier
- CFE0003277, ucf:48527
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003277
- Title
- Detection of Inorganic Phosphate in Environmental Water Samples using a Terbium and Gold Nanoparticle-based FRET Chemosensor.
- Creator
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Johnson, Madeleine, Campiglia, Andres, Zou, Shengli, Harper, James, Frazer, Andrew, Khondaker, Saiful, University of Central Florida
- Abstract / Description
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A novel chemosensor for the detection of inorganic phosphate (Pi) in environmental water samples is outlined. The sensing solution is comprised of a luminescent lanthanide, terbium (Tb3+), chelated to ethylenediaminetetraacetic acid (EDTA) acid in solution with cetyltrimethylammonium bromide (CTAB)- capped gold nanoparticles (AuNPs). The Tb-EDTA and AuNPs undergo a Fluorescence resonance energy transfer (FRET) mechanism in which the Tb3+ luminescence is quenched. Upon the addition of...
Show moreA novel chemosensor for the detection of inorganic phosphate (Pi) in environmental water samples is outlined. The sensing solution is comprised of a luminescent lanthanide, terbium (Tb3+), chelated to ethylenediaminetetraacetic acid (EDTA) acid in solution with cetyltrimethylammonium bromide (CTAB)- capped gold nanoparticles (AuNPs). The Tb-EDTA and AuNPs undergo a Fluorescence resonance energy transfer (FRET) mechanism in which the Tb3+ luminescence is quenched. Upon the addition of inorganic phosphate (Pi), the AuNPs begin to aggregate and precipitate out of solution. The aggregation of AuNPs results in the restoration of the Tb-EDTA signal which can then be correlated to Pi concentration in the matrix of analysis. The developed sensor has the potential for on-site monitoring of Pi in environmental waters at the sampling location; this would be advantageous for the prevention and understanding of eutrophication events caused by anthropogenic release of nutrients such as Pi. The limit of detection (LOD) of the luminescence sensor (83 ppb-Pi) is within the range of LODs previously reported for on-site monitoring of Pi. Quantitative analysis carried out via the multiple standard additions method provided accurate determination of Pi concentrations in heavily contaminated environmental waters. Additional studies include the synthesis of an organic antenna for the sensitization of the lanthanide ion and further improvement of detection levels.
Show less - Date Issued
- 2017
- Identifier
- CFE0006747, ucf:51874
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006747
- Title
- STORMWATER IRRIGATION OF SAINT AUGUSTINE GRASS:NITROGEN BALANCE AND EVAPOTRANSPIRATION.
- Creator
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Hulstein, Ewoud, Wanielista, Martin, University of Central Florida
- Abstract / Description
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A change in surface condition of a watershed, which is usually caused by development, can have measured effects on the naturally occurring hydrologic cycle and nitrogen cycle. This could result in environmental problems, such as reduced springflow and eutrophication. In an effort to address these issues, a combination of best management practices (BMPs) can be adhered to. The practice of using excess stormwater as a source for irrigation is proposed as a BMP for the minimization of impacts by...
Show moreA change in surface condition of a watershed, which is usually caused by development, can have measured effects on the naturally occurring hydrologic cycle and nitrogen cycle. This could result in environmental problems, such as reduced springflow and eutrophication. In an effort to address these issues, a combination of best management practices (BMPs) can be adhered to. The practice of using excess stormwater as a source for irrigation is proposed as a BMP for the minimization of impacts by development to the hydrologic and nitrogen cycles. To study the proposed BMP, a field experiment was installed in an outdoor location on the UCF main campus in Orlando, Florida. The experiment consists of three soil chambers, (2x2x4 ft, L:W:H), filled with compacted soil and covered with St. Augustine grass to simulate a suburban lawn. The grass was irrigated up to twice a week with detained stormwater with a nitrate nitrogen concentration of up to 2 mg/L. A mass balance and a total nitrogen balance were performed to determine evapotranspiration (ET) and impacts on groundwater nitrogen content. It was determined that the groundwater characteristics are largely dependent on the characteristics of the soil. The input nitrogen (precipitation and irrigation) was mostly in the form of nitrate and the output nitrogen (groundwater) was mostly in the form of ammonia. A total nitrogen mass balance indicated the mass output of nitrogen was significantly larger than mass input of nitrogen, which was due to ammonia leaching from the soil. Only small concentrations of nitrate were detected in the groundwater, resulting in an estimated nitrate removal (conversion to ammonia) of 97 percent at a depth of four feet when the input nitrate concentration was 2 mg/L. The average ET of the three chambers was compared to the estimated ET from the modified Blaney-Criddle equation on a monthly basis and a yearly basis. The modified Blaney-Criddle equation was proven to be accurate for estimating the actual ET for this application: irrigated St. Augustine grass in the Central Florida climate. In conclusion, using the available literature and the data collected from the field experiment, it was shown through an example design problem that the proposed BMP of using excess stormwater as a source for irrigation can help achieve a pre- versus postdevelopment volume balance and can help control post-development nitrate emissions.
Show less - Date Issued
- 2005
- Identifier
- CFE0000611, ucf:46511
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000611
- Title
- A THREE-DIMENSIONAL BAY/ESTUARY MODEL TO SIMULATE WATER QUALITY TRANSPORT.
- Creator
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Yu, Jing, Yeh, Gour-Tsyh, University of Central Florida
- Abstract / Description
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This thesis presents the development of a numerical water quality model using a general paradigm of reaction-based approaches. In a reaction-based approach, all conceptualized biogeochemical processes are transformed into a reaction network. Through the decomposition of species governing equations via Gauss-Jordan column reduction of the reaction network, (1) redundant fast reactions and irrelevant kinetic reactions are removed from the system, which alleviates the problem of unnecessary and...
Show moreThis thesis presents the development of a numerical water quality model using a general paradigm of reaction-based approaches. In a reaction-based approach, all conceptualized biogeochemical processes are transformed into a reaction network. Through the decomposition of species governing equations via Gauss-Jordan column reduction of the reaction network, (1) redundant fast reactions and irrelevant kinetic reactions are removed from the system, which alleviates the problem of unnecessary and erroneous formulation and parameterization of these reactions, and (2) fast reactions and slow reactions are decoupled, which enables robust numerical integrations. The system of species transport equations is transformed to reaction-extent transport equations, which is then approximated with two subsets: algebraic equations and kinetic-variables transport equations. As a result, the model alleviates the needs of using simple partitions for fast reactions. With the diagonalization strategy, it makes the inclusion of arbitrary number of fast and kinetic reactions relatively easy, and, more importantly, it enables the formulation and parameterization of kinetic reactions one by one. To demonstrate the general paradigm, QAUL2E was recasted in the mode of a reaction network. The model then was applied to the Loxahatchee estuary to study its response to a hypothetical biogeochemical loading from its surrounding drainage. Preliminary results indicated that the model can simulate four interacting biogeochemical processes: algae kinetics, nitrogen cycle, phosphorus cycle, and dissolved oxygen balance.
Show less - Date Issued
- 2006
- Identifier
- CFE0001372, ucf:46991
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001372
- Title
- A NEW PARADIGM OF MODELING WATERSHED WATER QUALITY.
- Creator
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Zhang, Fan, Yeh, Gour-Tsyh, University of Central Florida
- Abstract / Description
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Accurate models to reliably predict sediment and chemical transport in watershed water systems enhance the ability of environmental scientists, engineers and decision makers to analyze the impact of contamination problems and to evaluate the efficacy of alternative remediation techniques and management strategies prior to incurring expense in the field. This dissertation presents the conceptual and mathematical development of a general numerical model simulating (1) sediment and reactive...
Show moreAccurate models to reliably predict sediment and chemical transport in watershed water systems enhance the ability of environmental scientists, engineers and decision makers to analyze the impact of contamination problems and to evaluate the efficacy of alternative remediation techniques and management strategies prior to incurring expense in the field. This dissertation presents the conceptual and mathematical development of a general numerical model simulating (1) sediment and reactive chemical transport in river/stream networks of watershed systems; (2) sediment and reactive chemical transport in overland shallow water of watershed systems; and (3) reactive chemical transport in three-dimensional subsurface systems. Through the decomposition of the system of species transport equations via Gauss-Jordan column reduction of the reaction network, fast reactions and slow reactions are decoupled, which enables robust numerical integrations. Species reactive transport equations are transformed into two sets: nonlinear algebraic equations representing equilibrium reactions and transport equations of kinetic-variables in terms of kinetically controlled reaction rates. As a result, the model uses kinetic-variables instead of biogeochemical species as primary dependent variables, which reduces the number of transport equations and simplifies reaction terms in these equations. For each time step, we first solve the advective-dispersive transport of kinetic-variables. We then solve the reactive chemical system node by node to yield concentrations of all species. In order to obtain accurate, efficient and robust computations, five numerical options are provided to solve the advective-dispersive transport equations; and three coupling strategies are given to deal with the reactive chemistry. Verification examples are compared with analytical solutions to demonstrate the numerical accuracy of the code and to emphasize the need of implementing various numerical options and coupling strategies to deal with different types of problems for different application circumstances. Validation examples are presented to evaluate the ability of the model to replicate behavior observed in real systems. Hypothetical examples with complex reaction networks are employed to demonstrate the design capability of the model to handle field-scale problems involving both kinetic and equilibrium reactions. The deficiency of current practices in the water quality modeling is discussed and potential improvements over current practices using this model are addressed.
Show less - Date Issued
- 2005
- Identifier
- CFE0000448, ucf:46405
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000448
- Title
- An Assessment of Biosorption Activated Media for the Removal of Pollutants in Up-Flow Stormwater Treatment Systems.
- Creator
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Hood, Andrew, Randall, Andrew, Wanielista, Martin, Chopra, Manoj, O'Reilly, Andrew, Moore, Sean, University of Central Florida
- Abstract / Description
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Nitrogen and phosphorus are often the limiting nutrients for marine and freshwater systems respectively. Additionally, stormwater often contains elevated levels of pathogens which can pollute the receiving water body and impact reuse applications [1-4]. The reduction of limiting nutrients and pathogens is a common primary target for stormwater best management practices (BMPs) [5]. Traditional BMPs, such as retention/detention treatment ponds require large footprints and may not be practical...
Show moreNitrogen and phosphorus are often the limiting nutrients for marine and freshwater systems respectively. Additionally, stormwater often contains elevated levels of pathogens which can pollute the receiving water body and impact reuse applications [1-4]. The reduction of limiting nutrients and pathogens is a common primary target for stormwater best management practices (BMPs) [5]. Traditional BMPs, such as retention/detention treatment ponds require large footprints and may not be practical in ultra-urban environments where above ground space is limited. Upflow filters utilizing biosorption activated media (BAM) that can be placed underground offer a small footprint alternative. Additionally, BAM upflow filters can be installed at the discharge point of traditional stormwater ponds to provide further treatment. This research simulated stormwater that had already been treated for solids removal; thus, most of the nutrients and solids in the influent were assumed to be as non-settable suspended solids or dissolved solids. Three different BAM mixtures in an upflow filter configuration were compared for the parameters of nitrogen, phosphorus, total coliform, E. coli, and heterotrophic plate count (HPC). Additionally, genetic testing was conducted using Polymerase Chain Reaction (PCR), in conjunction with a nitrogen mass balance, to determine if Anammox was a significant player in the nitrogen removal. The columns were run at both 22-minute and 220-minute Empty Bed Contact Times (EBCTs). All the BAM mixtures analyzed were shown to be capable at the removal of nitrogen, phosphorus, and total coliform during both the 22-minute and 220-minute EBCTs, with BAM #1 having the highest removal performance for all three parameters during both EBCTs. All BAM mixtures experienced an increase in HPC. Additionally, PCR analysis confirmed the presence of Anammox in the biofilm and via mass balance it was determined that the biological nitrogen removal was due to Anammox and endogenous denitrification with Anammox being a significant mechanism.
Show less - Date Issued
- 2019
- Identifier
- CFE0007817, ucf:52875
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007817
