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Title: THREE DIMENSIONAL MODELING OF WEKIVA SPRINGSHED WITH WASH123D.
Creator: Paladagu, Sandeep, Gour-Tsyh, Yeh, University of Central Florida
Abstract / Description: This thesis presents a three-dimensional groundwater modeling of Wekia springshed in central Florida using a numerical model, WASH123D. Springs have historically played an important role in Florida's history. The Wekiva River is a spring-fed system associated with about 19 springs connected to the Floridan aquifer. With increased urbanization and population growth in this region, there has been an increased strain on the water levels of Floridan aquifer which is a major source of potable...
Show moreThis thesis presents a three-dimensional groundwater modeling of Wekia springshed in central Florida using a numerical model, WASH123D. Springs have historically played an important role in Florida's history. The Wekiva River is a spring-fed system associated with about 19 springs connected to the Floridan aquifer. With increased urbanization and population growth in this region, there has been an increased strain on the water levels of Floridan aquifer which is a major source of potable water. Maintaining groundwater recharge to the aquifer is a key factor of the viability of the regional water supply as well as Wekiva ecosystem. Hence, the first-principle, physics-based watershed model WASH123D has been applied to conduct the study of Wekiva "springshed", which is the recharge area and watershed contributing groundwater and surface water to the spring. In this work, the hydrogeologic conditions of the Wekiva springshed are discussed followed by the modeling details such as mathematical background, domain discretization and initial and boundary conditions considered. Finally, the results from the model are discussed. The Wekiva WASH123D model was run to evaluate the average, steady state 1995 hydrological conditions. The distribution of simulated Floridan aquifer system groundwater levels using WASH123D shows very good agreement with the field observations at corresponding locations.
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Date Issued: 2005
Identifier: CFE0000647, ucf:46530
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000647

Title: Modeling wastewater indicators and effects of contaminant removal strategies on groundwater and spring discharge in a karst aquifer.
Creator: Reed, Erin, Duranceau, Steven, Wang, Dingbao, Sadmani, A H M Anwar, Rowney, Alexander, University of Central Florida
Abstract / Description: This dissertation reports on research related to groundwater and contaminant transport to the Volusia Blue Spring (VBS), an Outstanding Florida Water Body located in Volusia County (Florida). The integration of springshed water quality and contaminant fate and transport (CFT) modeling played key roles in the evaluation of anthropogenic recharge impacts on VBS. To study anthropogenic recharge into the karst limestone aquifer, wastewater effluent, golf course ponds, septic tanks, groundwater...
Show moreThis dissertation reports on research related to groundwater and contaminant transport to the Volusia Blue Spring (VBS), an Outstanding Florida Water Body located in Volusia County (Florida). The integration of springshed water quality and contaminant fate and transport (CFT) modeling played key roles in the evaluation of anthropogenic recharge impacts on VBS. To study anthropogenic recharge into the karst limestone aquifer, wastewater effluent, golf course ponds, septic tanks, groundwater monitoring wells, and VBS discharge were sampled for boron, nitrate-nitrogen, nitrate-oxygen and their isotopes spatially throughout the VBS springshed. Data related to natural water features, rainfall, land use, water use, treated wastewater discharge, and septic tank effluent flows was used as inputs to the three-dimensional CFT model developed from an integration of MODFLOW-2000 and MT3DMS. The model was calibrated and validated from field observed water levels and water quality taken throughout the springshed. The purpose of this model is to understand groundwater and spring water quality throughout the VBS springshed. Water quality and model results indicate that water from the surficial aquifer in surrounding urban areas contributed to the flow and water quality at the spring's boil. Protection scenarios that included wetland treatment systems and the conversion of targeted septic systems to sewer were simulated to estimate future reductions of anthropogenic nutrients transported to the Spring. Of the scenarios evaluated in this study, targeted septic system removal results in the greatest benefit with a 36% nitrate decrease in a forty-year projection of spring discharge water quality. Results from this combined water quality and model development approach is expected to contribute an understanding of anthropogenic impacts from the urbanized developments overlying and surrounding the karst VBS aquifer.
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Date Issued: 2016
Identifier: CFE0006701, ucf:51903
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006701

Title: Suspended Solids and Deep Well Injection Systems.
Creator: Smedley, D. Robert, Hartman, J. Paul, Engineering
Abstract / Description: Florida Technological University College of Engineering Thesis; A test method and the associated equipment have been developed to investigate the effect of suspended solids on the flow of fluid into a deep injection well system. Preliminary testing indicates that the equipment and test method can be used to determine the permeability of rock samples with a high degree of accuracy. Additionally, this equipment can be used in a testing program which will eventually lead to the development of...
Show moreFlorida Technological University College of Engineering Thesis; A test method and the associated equipment have been developed to investigate the effect of suspended solids on the flow of fluid into a deep injection well system. Preliminary testing indicates that the equipment and test method can be used to determine the permeability of rock samples with a high degree of accuracy. Additionally, this equipment can be used in a testing program which will eventually lead to the development of guidelines for the degree of pre-injection treatment required for suspended solids so that the operational life of the well is not impaired.
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Date Issued: 1975
Identifier: CFR0008135, ucf:52948
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0008135

Title: A Study of the Degradative Capabilities of the Bimetallic System: Mg(Pd/C) as Applied in the Destruction of Decafluoropentane, an Environmental Contaminant.
Creator: Tomlin, Douglas, Clausen, Christian, Yestrebsky, Cherie, Hampton, Michael, Elsheimer, Seth, Griffin, Timothy, University of Central Florida
Abstract / Description: Pollution from hydrofluorocarbons (HFCs) poses a serious challenge to the environmental community. Released from industrial operations, they have contaminated both the atmosphere and groundwater and are considered persistent in both media. For over the past 20 years, the practice of synthesizing HFCs as alternatives to chlorofluorocarbons (CFCs) has been conducted in an effort to reverse the effects of stratospheric ozone layer depletion. HFCs also exhibit desirable properties as precision...
Show morePollution from hydrofluorocarbons (HFCs) poses a serious challenge to the environmental community. Released from industrial operations, they have contaminated both the atmosphere and groundwater and are considered persistent in both media. For over the past 20 years, the practice of synthesizing HFCs as alternatives to chlorofluorocarbons (CFCs) has been conducted in an effort to reverse the effects of stratospheric ozone layer depletion. HFCs also exhibit desirable properties as precision cleaning solvents due to their low surface energies but that use has lead to releases contaminating groundwater resulting in recalcitrant pollution in the form of dense non-aqueous phase liquids (DNAPLs). Results from studies requested by the EPA have shown HFCs to exhibit developmental and neurological damage in animal life along with their impact to humans remaining not completely understood. Therefore, the potential hazards of HFCs to human health and the environment necessitates the development of an effective and environmentally responsible technology for their remediation from groundwater. The National Aeronautics and Space Administration (NASA) has employed the use of various halogenated solvents in its spacecraft cleaning operations at its facilities for many years and in that time experienced accidental releases which eventually resulted in environmental contamination. Many of the organic solvents employed in these operations consisted of halogenated compounds with most being partially chlorinated and fluorinated hydrocarbons. Through normal use and operation, releases of these materials found their way into the environs of atmosphere, soil and groundwater. Remediation of fluorinated compounds has not followed the successful path laid by clean-up technologies developed for their chlorinated counterparts. Fluorinated compounds are resistant however to those methods due to their unreactive nature stemming from the properties of the strong carbon-fluorine bond. This unique bonding property also ensures that their environmental persistence endures. One particular fluorinated groundwater contaminant, the HFC 1,1,1,2,2,3,4,5,5,5-decafluoropentane (DFP), which has been used by NASA since the late 1990's was selected as the focus of this study. For this study, various reductive metal systems were evaluated for their capability towards effective degradation of DFP. These included the metals: iron, magnesium, aluminum and zinc and several bimetallic alloys as well as on carbon support. Variations in protic solvent reaction media and acidic metal activation were also explored. The bimetallic reductive catalytic alloy Magnesium with Palladium on Carbon, Mg(Pd/C), in aqueous media proved to be the successful candidate with 100% conversion to simple hydrocarbons. Mechanistic evaluation for degradation is proposed via a series of stepwise catalytic hydrodefluorination reactions. Kinetic studies revealed degradation to obey second order reaction kinetics. Further study should be conducted optimizing an in situ groundwater delivery method for field application. Additionally, the developed technology should be assessed against other groundwater fluorocarbon pollutants; either as a method for remediating multiple fluorinated polluted sites or as a polishing agent where all other pollutants have been abated.
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Date Issued: 2012
Identifier: CFE0004798, ucf:49742
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004798

Title: Assessing the Impact of Radionuclides Released into the Floridan Aquifer by a Massive Sinkhole on Local Municipal Water Supplies.
Creator: Arenas Daza, Maria, Duranceau, Steven, Sadmani, A H M Anwar, Wang, Dingbao, University of Central Florida
Abstract / Description: In late August 2016, a sinkhole spanning 45 feet (13.7 meters) in diameter opened at a phosphate fertilizer facility (Mosaic Company) near Mulberry, Florida, leaking an estimated 215 million gallons (813,000 cubic meters) of radionuclide-contaminated water 300 feet into the Floridan aquifer. An investigation to determine possible impacts to the environment and local community drinking water supplies was implemented that focused on two 1.5 million gallon per day (MGD) Tampa Bay Water (TBW)...
Show moreIn late August 2016, a sinkhole spanning 45 feet (13.7 meters) in diameter opened at a phosphate fertilizer facility (Mosaic Company) near Mulberry, Florida, leaking an estimated 215 million gallons (813,000 cubic meters) of radionuclide-contaminated water 300 feet into the Floridan aquifer. An investigation to determine possible impacts to the environment and local community drinking water supplies was implemented that focused on two 1.5 million gallon per day (MGD) Tampa Bay Water (TBW) production wells and two Polk County Utilities (PCU) water treatment facilities. Water samples collected between June 2017 and January 2018 at the TBW and PCU sites were found to contain radionuclides below regulated levels. To evaluate the effectiveness of membrane treatment should the TBW and PCU drinking water wells be affected by the spill in the future, bench-scale, flat-sheet reverse osmosis (RO) and nanofiltration (NF) membrane process testing was performed using TBW and PCU wellfield sample aliquots. NF and RO were shown to be capable of removing at minimum of 86 and 92 percent, respectively, of the barium content that had been spiked into groundwater testing aliquots. Based on testing results, a conceptual opinion of probable capital cost for a membrane process ranged from $1.7 and $3.5 million for a 0.25 MGD and 2.0 MGD design capacity, respectively. Process operation and maintenance costs ranged between $0.99/Kgal and $0.26/Kgal for a 0.25 MGD and 2.0 MGD design capacity, respectively. The amortized total cost based on a 20-year period and 8 percent interest rate ranged between $1.88/Kgal for a 0.25 MGD and $0.49/Kgal for a 2.0 MGD design capacity plant. An estimate of unavailable water value due to a long-term well shut-down was approximated as $0.64/Kgal.
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Date Issued: 2018
Identifier: CFE0006970, ucf:52911
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006970

Title: Groundwater modeling for assessing the impacts of natural hazards in east-central Florida.
Creator: Xiao, Han, Wang, Dingbao, Nam, Boo Hyun, Medeiros, Stephen, Mayo, Talea, Hall, Carlton, University of Central Florida
Abstract / Description: In coastal east-central Florida (ECF) , the low-lying coastal alluvial plains and barrier islands have a high risk of being inundated by seawater due to climate change effects such as sea-level rise, changing rainfall patterns, and intensified storm surge from hurricanes., This will produce saltwater intrusion into the coastal aquifer from infiltration of overtopping saltwater. In the inland ECF region, sinkhole occurrence is recognized as the primary geologic hazard causing massive financial...
Show moreIn coastal east-central Florida (ECF) , the low-lying coastal alluvial plains and barrier islands have a high risk of being inundated by seawater due to climate change effects such as sea-level rise, changing rainfall patterns, and intensified storm surge from hurricanes., This will produce saltwater intrusion into the coastal aquifer from infiltration of overtopping saltwater. In the inland ECF region, sinkhole occurrence is recognized as the primary geologic hazard causing massive financial losses to society in the past several decades. The objectives of this dissertation are to: (1) evaluate the impacts of sea-level rise and intensified storm surge on the extent of saltwater intrusion into the coastal ECF region; (2) assess the risk level of sinkhole occurrence in the inland ECF region. In this dissertation, numerical modeling methods are used to achieve these objectives. Several three-dimensional groundwater flow and salinity transport models, focused on the coastal ECF region, are developed and calibrated to simulate impacts of sea-level rise and storm surge based on various sea-level rise scenarios. A storm surge model is developed to quantify the future extent of saltwater intrusion. Several three-dimensional groundwater flow models, focused on the inland ECF region, are developed and calibrated to simulate the spatial variation of groundwater recharge rate for analyzing the risk level of sinkhole occurrence in the geotypical central Florida karst terrains. Results indicate that sea-level rise and storm surge play a dominant role in causing saltwater intrusion, and the risk of sinkhole occurrence increases linearly with an increase in recharge rate while the timing of sinkhole occurrence is highly related to the temporal variation of the difference of groundwater level between confined and unconfined aquifers. The outcome will contribute to ongoing research focused on forecasting the impacts of climate change on the risk level of natural hazards in ECF region.
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Date Issued: 2017
Identifier: CFE0007298, ucf:52160
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007298

Title: Nanofiltration of Perfluorinated Compounds as a Function of Water Matrix Properties.
Creator: Toure, Hadi, Sadmani, A H M Anwar, Duranceau, Steven, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: Perfluorinated compounds (PFCs) have been manufactured and used in various industries including food packaging, paintings, and coating industries. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most commonly investigated PFCs that have bioaccumulative properties and a strong persistence in environment. Despite the growing interest in using membrane technology to remove PFOA and PFOS from water, little information is available on the impact of natural water...
Show morePerfluorinated compounds (PFCs) have been manufactured and used in various industries including food packaging, paintings, and coating industries. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most commonly investigated PFCs that have bioaccumulative properties and a strong persistence in environment. Despite the growing interest in using membrane technology to remove PFOA and PFOS from water, little information is available on the impact of natural water matrices on the removal of PFOA and PFOS when using nanofiltration (NF). The presence of natural organic matter (NOM) and cations (Ca2+ and Mg2+) in water matrices and their interactions with the PFCs may significantly impact their removal efficiency. The current study compared the rejection of PFOA and PFOS from laboratory-prepared water (deionized water), surface water and groundwater using a commercial NF membrane (NE 70). Three different experiments were conducted for 20 hours using a bench- scale flat sheet unit. Feed and permeate samples were collected and analyzed to determine the PFOA and PFOS concentrations using liquid chromatography-tandem mass spectrometry (LC/MS-MS). The compound rejections varied from 71 to 80 % for PFOA and 42 to 80 % for PFOS. The results showed increased rejection of PFOA/S in the surface water and groundwaters when compared to the laboratory-prepared water. This is likely due to the presence of NOM and cations in the natural water matrices. The permeate flux declined (12.3-56.2 %) as more cations and NOM were present in the feedwater, suggesting that the increased rejection of PFOS in natural waters may be due to membrane pore blockage.
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Date Issued: 2018
Identifier: CFE0007589, ucf:52539
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007589

Title: Physical Hydrogeological Modeling of Florida's Sinkhole Hazard.
Creator: Perez, Adam, Nam, Boo Hyun, Wang, Dingbao, Chopra, Manoj, Singh, Arvind, An, Jin Woo, University of Central Florida
Abstract / Description: Sinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole...
Show moreSinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole states.The scope of this study is to develop a physical model to simulate sinkholes (referred to as a sinkhole simulator), which can assess the qualitative behavior of the hydrogeological mechanism of Florida's sinkhole formations. Two sinkhole simulators were developed, with the second simulator constructed to overcoming the limitations of the first. The first generation sinkhole simulator incorporated a falling head groundwater system and the sinkhole could only be observed once the ground surface was breached. The second generation sinkhole simulator incorporated a constant head groundwater system which accurately depicts field conditions and the sinkhole was able to be observed during all stages of formation within this model. In both simulators multiple hydrogeological conditions were created and water level transducers were installed at various locations within the soil profile to monitor variations in the groundwater table during the sinkhole process, this was done to investigate the soil-groundwater behavior.Findings from this study include: 1) groundwater recharge is a critical sinkhole triggering factor, 2) the groundwater table cone of depression increases as the raveled zone or void travels up through the overburden due to sinkhole formation, 3) The cover-subsidence sinkhole failure mechanism is similar to the failure mechanism present in Terzaghi's trapdoor experiment and the cover-collapse failure mechanism consists of four district components: failure planes with erosion envelope, arch dropout failure, formation of elliptical void, and slope stability failure, and 4) a strong qualitative relationship between soil strength and type of sinkhole formed (cover-subsidence or cover-collapse) was observed.
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Date Issued: 2017
Identifier: CFE0006637, ucf:51247
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006637

Title: Modeling Mass Transfer and Assessing Cost and Performance of a Hollow Fiber Nanofiltration Membrane Process.
Creator: Yonge, David, Duranceau, Steven, Sadmani, A H M Anwar, Lee, Woo Hyoung, Clausen, Christian, University of Central Florida
Abstract / Description: Bench-scale water treatment testing of three next generation hollow-fiber (HF) nanofiltration (NF) membranes was conducted to characterize divalent ion rejection capabilities and investigate removal mechanisms. Existing mathematical models were investigated to describe solute transport using synthetic magnesium sulfate solutions including the size exclusion model, homogenous solution diffusion (HSD) model, dimensional analysis, and the HSD model incorporating film theory. Solute transport for...
Show moreBench-scale water treatment testing of three next generation hollow-fiber (HF) nanofiltration (NF) membranes was conducted to characterize divalent ion rejection capabilities and investigate removal mechanisms. Existing mathematical models were investigated to describe solute transport using synthetic magnesium sulfate solutions including the size exclusion model, homogenous solution diffusion (HSD) model, dimensional analysis, and the HSD model incorporating film theory. Solute transport for two of the membranes were described by HSD theory and were predictive of their 90% divalent ion removal. A third membrane was more accurately modeled using size exclusion and was found to be predictive of its 40% divalent ion rejection. Feed ionic strength variation was shown to significantly impact rejection. In this work, semi-empirical models were developed to describe solute transport under varying feed ionic strength conditions. Bench-scale testing of aerated groundwater confirmed the HFNF membrane divalent ion rejection capabilities. Pilot testing of a commercially available HFNF membrane was shown to remove divalent ions and dissolved organic carbon (DOC) by 10% and 25%, respectively. Financial evaluations indicated that HFNF offered cost savings over traditional spiral-wound (SW) NF, $0.60/kgal versus $0.85/kgal operating costs, respectively. Traditional SWNF membranes produced superior water quality achieving 90% divalent ion removal and 96% DOC removal but required media and membrane filtration pretreatment. When considering the costs of constructing a new 2 million gallon per day (permeate) HFNF process, conceptual cost comparisons revealed that HFNF technologies could reduce capital costs by approximately $1 million, and operating costs by $0.27/kgal for an 85% recovery plant.
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Date Issued: 2016
Identifier: CFE0006549, ucf:51346
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006549

Title: Annual water balance model based on generalized proportionality relationship and its applications.
Creator: Tang, Yin, Wang, Dingbao, Kibler, Kelly, Singh, Arvind, Sumner, David, Quintana-Ascencio, Pedro, University of Central Florida
Abstract / Description: The main goal of this dissertation research is to derive a type of conceptual models for annual water balance at the watershed scale. The proportionality relationship from the Soil Conservation Service Curve Number method was generalized to annual scale for deriving annual water balance model. As a result, a one-parameter Budyko equation was derived based on one-stage partitioning; and a four-parameter Budyko equation was derived based on two-stage partitioning. The derived equations balance...
Show moreThe main goal of this dissertation research is to derive a type of conceptual models for annual water balance at the watershed scale. The proportionality relationship from the Soil Conservation Service Curve Number method was generalized to annual scale for deriving annual water balance model. As a result, a one-parameter Budyko equation was derived based on one-stage partitioning; and a four-parameter Budyko equation was derived based on two-stage partitioning. The derived equations balance model parsimony and representation of dominant hydrologic processes, and provide a new framework to disentangle the roles of climate variability, vegetation, soil and topography on long-term water balance. Three applications of the derived equations were demonstrated. Firstly, the four-parameter Budyko equation was applied to 165 watersheds in the United States to disentangle the roles of climate variability, vegetation, soil and topography on long-term water balance. Secondly, the one-parameter Budyko equation was applied to a large-scale irrigation region. The historical annual total water storage change were reconstructed for assessing groundwater depletion due to irrigation pumping by integrating the derived equation and the satellite-based GRACE (Gravity Recovery and Climate Experiment) data. Thirdly, the one-parameter Budyko equation was used to model the impact of willow treatment on annual evapotranspiration through a two-year field experiment in the Upper St. Johns River marshes. An empirical relationship between the parameter and willow fractional coverage was developed, providing a useful tool for predicting long-term response of evapotranspiration to willow treatment. ?
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Date Issued: 2017
Identifier: CFE0006958, ucf:51638
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006958

Title: Green Technologies and Sensor Networks for BMP Evaluation in Stormwater Retention Ponds and Wetlands.
Creator: Crawford, Anthony, Chang, Ni-bin, Wanielista, Martin, Lee, Woo Hyoung, University of Central Florida
Abstract / Description: The aim of this thesis is to examine and develop new techniques in stormwater Best Management Practices (BMP) for nutrient and erosion reduction and monitoring by incorporation of low impact green technologies and sensor networks. Previous research has found excessive nutrient loading of nitrogen and phosphorus species from urban stormwater runoff can lead to ecological degradation and eutrophication of receiving lakes and rivers (Fareed and Abid, 2005). In response, the Florida Department of...
Show moreThe aim of this thesis is to examine and develop new techniques in stormwater Best Management Practices (BMP) for nutrient and erosion reduction and monitoring by incorporation of low impact green technologies and sensor networks. Previous research has found excessive nutrient loading of nitrogen and phosphorus species from urban stormwater runoff can lead to ecological degradation and eutrophication of receiving lakes and rivers (Fareed and Abid, 2005). In response, the Florida Department of Environmental Protection (FDEP) has set forth reduction goals as established in Total Maximum Daily Load (TMDL) reports to reduce nutrient loading and restore, or maintain, Florida water bodies to reasonable conditions. Often times current stormwater management practices are not sufficient to attain these goals and further improvements in system design are required. In order to reach these goals, affordable technologies designed for both nutrient reduction and monitoring of system performance to deepen and improve our understanding of stormwater processes are required. Firstly this thesis examines the performance of three types of continuous-cycle Media Bed Reactors (MBRs) using Bio-activated Adsorptive Media (BAM) for nutrient reduction in three retention ponds located throughout the Central Florida region. Chapter 2 examines the use of a Sloped and Horizontal MBRs arranged in a baffling configuration, whereas Chapter 3 examines the field performance of a Floating MBR arranged in an upflow configuration. Each MBR was analyzed for performance in reducing total phosphorus, soluble reactive phosphorus, total nitrogen, organic nitrogen, ammonia, nitrates + nitrites, turbidity and chlorophyll a species as measured from the influent to effluent ends of the MBR. The results of the experiments indicate that MBRs may be combined with retention ponds to provide (")green technology(") alternatives for inter-event treatment of nutrient species in urban stormwater runoff by use of recyclable sorption media and solar powered submersible pumps. Secondly the thesis focusses on three new devices for BMP monitoring which may be integrated into wireless networks, including a Groundwater Variable Probe (GVP) for velocity, hydraulic conductivity and dispersion measurements in a retention pond bank (Chapter 4), an affordable Wireless Automated Sampling Network (WASN) for sampling and analysis of nutrient flux gradients in retention ponds (Chapter 5), and finally an Arc-Type Automated Pulse Tracer Velocimeter (APTV) for low velocity and direction surface water measurements in retention ponds and constructed wetlands (Chapter 6). The GVP was integrated with other environmental sensing probes to create a remote sensing station, capable of real-time data analysis of sub-surface conditions including soil moisture, water table stage. Such abilities, when synced with user control capabilities, may help to increase methods of monitoring for applications including erosion control, bank stability predictions, monitoring of groundwater pollutant plume migration, and establishing hydraulic residence times through subsurface BMPs such as permeable reactive barriers. Advancement of this technology may be used by establishing additional sub-stations, thereby creating sensing networks covering broader areas on the kilometer scale. Two methods for velocity calculation were developed for the GVP for low flow (Pe (<) 0.2) and high flow (Pe (>) 0.6) conditions. The GVP was found to operate from a 26-505 cmd-1 range in the laboratory to within (&)#177;26% of expected velocities for high-flow conditions and effectively measure directional flow angles to within (&)#177;14? of expected. Hydraulic conductivity measurements made by the GVP were confirmed to within (&)#177;12% as compared to laboratory measurements. The GVP was found capable of measuring the dispersion coefficient in the laboratory, however turbulent interferences caused during injection was found to occur. Further advancement of the technology may be merited to improve dispersion coefficient measurements. Automated water sampling can provide valuable information of the spatial and temporal distribution of pollutant loading in surface water environments. This ability is expanded with the development of the WASN, providing an affordable, ease-of-use method compared to conventional automated water samplers currently on the market. The WASN was found to effectively operate by text activation via GSM cellular networks to an activation module. Propagation of the signal was distributed to collection units via XBee modules operating on point-to-point star communication using an IEEE 802.15.4 protocol. Signal communications effectively transmitted in the field during a storm event to within a range of 200 feet and collected 50 (&)#177;4 ml samples at synced timed increments. A tracer study confirmed that no mixing of samples occurs when a factor of safety of 2 is applied to flush times. This technology provides similar abilities to current market devices at down to 10% of the cost, thereby allowing much more sampling locations for a similar budget. The Arc-Type APTV is useful in establishing both low range horizontal velocity fields and expanding low range velocity measurements below detection ranges of mechanical velocity meters. Installation of a field station showed system functionality, which may be integrated with other environmental sensing probes for surface water testing. This may assist in nutrient distribution analysis and understanding the complex behavior of hydraulic retention times within wetland systems. The device was found to work effectively in both lab and field environments from a 0.02 (-) 5.0 cms-1 range and measure velocity within approximately (&)#177;10% of an acoustic Doppler velocimeter and within an average of (&)#177;10? of directional measurements. A drop in accuracy was measured for velocity ranges (>)4.5 cms-1. The field station operated on 3G CDMA cellular network two-way communication by installation of a Raven cellular modem. Use of LoggerNet software allowed control and data acquisition from anywhere with an internet connection. This thesis also introduces brief discussions on expanding these (")point(") measurement technologies into sensing networks. Installation of sub-stations with communication protocols to one central master node station may broaden the sensing system into much larger kilometer-scale ranges, thus allowing large spatial analysis of environmental conditions. Such an integration into controllable sensing networks may help bridge the gap and add calibration and verification abilities between fine-resolution (")point(") measurements and large scale technologies such as Electrical Resistivity Tomography and satellite remote sensing. Furthermore, application of sensing networks may assist in calibration and verification of surface and groundwater models such as ModFlow, SVFlux and FEHM.
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Date Issued: 2014
Identifier: CFE0005776, ucf:50066
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005776

Title: Base Flow Recession Analysis for Streamflow and Spring Flow.
Creator: Ghosh, Debapi, Wang, Dingbao, Chopra, Manoj, Singh, Arvind, Medeiros, Stephen, Bohlen, Patrick, University of Central Florida
Abstract / Description: Base flow recession curve during a dry period is a distinct hydrologic signature of a watershed. The base flow recession analysis for both streamflow and spring flow has been extensively studied in the literature. Studies have shown that the recession behaviors during the early stage and the late stage are different in many watersheds. However, research on the transition from early stage to late stage is limited and the hydrologic control on the transition is not completely understood. In...
Show moreBase flow recession curve during a dry period is a distinct hydrologic signature of a watershed. The base flow recession analysis for both streamflow and spring flow has been extensively studied in the literature. Studies have shown that the recession behaviors during the early stage and the late stage are different in many watersheds. However, research on the transition from early stage to late stage is limited and the hydrologic control on the transition is not completely understood. In this dissertation, a novel cumulative regression analysis method is developed to identify the transition flow objectively for individual recession events in the well-studied Panola Mountain Research Watershed in Georgia, USA. The streamflow at the watershed outlet is identified when the streamflow at the perennial stream head approaches zero, i.e., flowing streams contract to perennial streams. The identified transition flows are then compared with observed flows when the flowing stream contracts to the perennial stream head. As evidenced by a correlation coefficient of 0.90, these two characteristics of streamflow are found to be highly correlated, suggesting a fundamental linkage between the transition of base flow recession from early to late stages and the drying up of ephemeral streams. At the early stage, the contraction of ephemeral streams mostly controls the recession behavior. At the late stage, perennial streams dominate the flowing streams and groundwater hydraulics governs the recession behavior. The ephemeral stream densities vary from arid regions to humid regions. Therefore, the characteristics of transition flow across the climate gradients are also tested in 40 watersheds. It is found that climate, which is represented by climate aridity index, is the dominant controlling factor on transition flows from early to late recession stages. Transition flows and long-term average base flows are highly correlated with a correlation coefficient of 0.82. Long-term average base flow and the transition flow of recession are base flow characteristics at two temporal scales, i.e., the long-term scale and the event scale during a recession period. This is a signature of the co-evolution of climate, vegetation, soil, and topography at the watershed scale. The characteristics of early and late recession are applied for quantifying human impacts on streamflow in agricultural watersheds with extensive groundwater pumping for irrigation. A recession model is developed to incorporate the impacts of human activities (such as groundwater pumping) and climate variability (such as evapotranspiration) on base flow recession. Groundwater pumping is estimated based on the change of observed base flow recession in watersheds in the High Plains Aquifer. The estimated groundwater pumping rate is found consistent compared with the observed data of groundwater uses for irrigation. Besides streamflow recession analysis, this dissertation also presents a novel spring recession model for Silver Springs in Florida by incorporating groundwater head, spring pool altitude, and net recharge into the existing Torricelli model. The results show that the effective springshed area has continuously declined since 1988. The net recharge has declined since the 1970s with a significant drop in 2002. Subsequent to 2002, the net recharge increased modestly but not to the levels prior to the 1990s. The decreases in effective springshed area and net recharge caused by changes in hydroclimatic conditions including rainfall and temperature, along with groundwater withdrawals, contribute to the declined spring flow.
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Date Issued: 2015
Identifier: CFE0005951, ucf:50814
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005951

Title: Evaluation of an On-Line Device to Monitor Scale Formation in a Brackish Water Reverse Osmosis Membrane Process.
Creator: Roque, Jennifer, Duranceau, Steven, Randall, Andrew, Zhang, Husen, University of Central Florida
Abstract / Description: A modified two-element membrane pressure vessel assembly has been used to monitor process operational changes in a full-scale reverse osmosis (RO) water treatment plant (WTP). This study evaluated the effectiveness of the assembly as an on-line monitoring device intended to detect scale formation conditions when connected to an operating RO process train. This study was implemented to support the requirements of a larger University of Central Florida (UCF) research project ongoing at the city...
Show moreA modified two-element membrane pressure vessel assembly has been used to monitor process operational changes in a full-scale reverse osmosis (RO) water treatment plant (WTP). This study evaluated the effectiveness of the assembly as an on-line monitoring device intended to detect scale formation conditions when connected to an operating RO process train. This study was implemented to support the requirements of a larger University of Central Florida (UCF) research project ongoing at the city of Sarasota's Public Works and Utilities (City) water treatment facilities located in Sarasota, Florida. During the time-frame of this study, the City was in the process of eliminating their sulfuric acid feed from the pretreatment system of their existing 4.5 million gallon per day (MGD) RO membrane process. The City was motivated to eliminate its dependence on sulfuric acid to reduce operating costs as well as reduce operation health and safety risks associated with the use of the acid as a pretreatment chemical. Because the City was concerned with secondary process impacts associated with acid elimination, additional measures were desired in order to protect the full-scale process.This thesis reports on the design, fabrication and installation of a third-stage two membrane element pressure vessel (")canary(") sentinel monitoring device (Canary), its effectiveness as an on-line scaling monitor during full-scale acid elimination, and presents the results of the study. The Canary sentinel device was controlled using the normalized specific flux of the two membrane elements fed by a portion of the second stage concentrate of one of the City's full-scale RO process skids. Although the Canary demonstrated the ability to detect changes in an RO process operation, scaling did not occur under the conditions evaluated in this study. An autopsy of one of the Canary elements revealed that no scaling had occurred during the acid elimination process. Therefore, the Canary was found to be useful in its function as a sentinel, even though no scaling was detected by the device after acid elimination at the City's full-scale plant had been accomplished.
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Date Issued: 2012
Identifier: CFE0004433, ucf:49353
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004433

Title: Sinkhole Monitoring Using Groundwater Table Data.
Creator: Tu, Ton, Yun, Hae-Bum, Nam, Boo Hyun, Wang, Dingbao, University of Central Florida
Abstract / Description: Florida might be one of the most sinkhole-active areas on the earth. Due to its unpredictability and significance of occurrence, the development of sinkhole monitoring techniques is imperative to minimize sinkhole-induced hazards. Several methods have been used to evaluate sinkhole risks, including destructive methods, such as Standard Penetrating Tests (SPT) and Cone Penetrating Tests (CPT), geophysical method, and sensor-based groundwater monitoring method. However, few studies are...
Show moreFlorida might be one of the most sinkhole-active areas on the earth. Due to its unpredictability and significance of occurrence, the development of sinkhole monitoring techniques is imperative to minimize sinkhole-induced hazards. Several methods have been used to evaluate sinkhole risks, including destructive methods, such as Standard Penetrating Tests (SPT) and Cone Penetrating Tests (CPT), geophysical method, and sensor-based groundwater monitoring method. However, few studies are available for comprehensive understanding of spatiotemporal sinkhole mechanism by combining different exploration methods under realistic experimental conditions. The objective of this study is to understand spatiotemporal sinkhole mechanism, using SPT, CPT, ground penetrating radar (GPR), and piezo pressure sensors tested at actual sinkhole sites. A small-scale test was conducted prior to the field test to validate data analysis technique using piezo pressure sensors, developed in this study. Eight piezo pressure sensors were used located at different distances from the sinkhole center to measure the ground water levels (GWLs) during artificially made sinkhole events. A total of 24 scaled tests was conducted with different sinkhole soil thickness and initial GWL. The cone of water depression was observed during the tests, which indicates there are strong relationship between sinkhole and sinkhole occurrence. A novel peak-counting method was developed and validated to estimate spatiotemporal relations of the relations between GWLs and sinkhole collapse patterns.The field test was conducted at an active sinkhole site in Lake county, Florida to determine locations of points of breach and to monitor fluctuation GWL over time. Twenty piezometer sensors were installed, and the GWLs were monitored for three months at 30-min sampling rate. The daily moving average of GWL was calculated and visualized in ArcGIS map to understand spatiotemporal behavior of GWL at different locations from sinkhole positions. The monitoring results were compared with CPT, SPT and GPR results that were conducted prior to the piezo sensor installations. Strong correlations were observed between CPT, SPT, GPR and GWL results. From the results, it can be concluded that size and shape of the cone of water depression depend on dimensions of point discharges and properties of surrounding soil.
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Date Issued: 2016
Identifier: CFE0006511, ucf:51383
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006511

Title: Experimental Study of Sinkhole Failure Related to Groundwater Level Drops.
Creator: Alrowaimi, Mohamed, Chopra, Manoj, Nam, Boo Hyun, Yun, Hae-Bum, Sallam, Amr, University of Central Florida
Abstract / Description: Sinkholes are natural geohazard phenomena that cause damage to property and may lead to loss of life. They can also cause added pollution to the aquifer by draining unfiltered water from streams, wetland, and lakes into the aquifer. Sinkholes occur in a very distinctive karst geology where carbonate, limestone, dolomite, or gypsum, are encountered as the bedrock that can naturally be dissolved by groundwater circulating through them. Sinkholes can occur gradually or suddenly with catastrophic...
Show moreSinkholes are natural geohazard phenomena that cause damage to property and may lead to loss of life. They can also cause added pollution to the aquifer by draining unfiltered water from streams, wetland, and lakes into the aquifer. Sinkholes occur in a very distinctive karst geology where carbonate, limestone, dolomite, or gypsum, are encountered as the bedrock that can naturally be dissolved by groundwater circulating through them. Sinkholes can occur gradually or suddenly with catastrophic impact depending on the geology and hydrology of the area. Predicting the formation and the collapse of a sinkhole based on the current ground investigation technologies is limited by the high levels of uncertainties in the soil properties and behavior. It is possible that progressing sinkholes can be missed by geotechnical site investigations especially during the development of a very wide area. In this study, a laboratory-scale sinkhole model was constructed to physically simulate the sinkhole phenomenon. The physical model was designed to monitor a network of groundwater table over time around a predetermined sinkhole location. This model was designed to establish a correlation between the groundwater table drops and the sinkhole development. The experimental small-scale model showed that there is a groundwater cone of depression that forms prior the surface collapse of the sinkhole. The cone of water depression can be used to identify the potential location of the sinkhole at early stage of the overburden underground cavities formation in a reverse manner. In addition, monitoring of single groundwater well showed that groundwater level signal has some sudden water drops (progressive drops) which occur at different times (time lags) during the sinkhole development. A time frequency analysis was also used in this study to detect the pattern of these progressive drops of the groundwater table readings. It is observed, based on the model, that the development and growth of sinkhole can be correlated to progressive drops of the groundwater table since the drops start at the monitoring wells that are closer radially to the center of the sinkhole. Subsequently, with time, these drops get transferred to more distant monitoring wells. The time frequency analysis is used to decompose and detect the progressive drops by using a Pattern Detection Algorithm called Auto Modulating Detection Pattern Algorithm (AMD), which was developed by Yun (2013). The results of this analysis showed that the peaks of these progressive drops in the raw groundwater readings are a good indicator of the potential location of sinkholes at early stage when there are no any visible depression of the ground surface. Finally, the effect of several soil parameters on the cone of the water depression during the sinkhole formation is studied. The parametric study showed that both of overburden soil thickness and the initial (encountered) groundwater table level have a clear impact on the time of the sinkhole collapse. While this model used a predetermined crack location to study the groundwater level response around it, the concept of groundwater drops as an indicator of sinkhole progression and collapse may be used to determine the ultimate location of the sinkhole. By monitoring the changes in natural groundwater levels in the field from either an existing network of groundwater monitoring wells or additional installation, the methodology discussed in this dissertation may be used for possible foreseeing of the surface collapse of sinkholes.
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Date Issued: 2016
Identifier: CFE0006249, ucf:51060
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006249

Title: Investigating Novel Water Treatment Methods and Monitoring Techniques for Sulfide-Laden Groundwater Supplies.
Creator: Yoakum, Benjamin, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, Moore, Sean, University of Central Florida
Abstract / Description: This dissertation reports on research related to novel water treatment and monitoring techniques for sulfide-laden groundwater supplies. The dissertation is divided into several chapters with four core chapters focused on investigations studying a novel water treatment method or monitoring technique. The first investigation assessed the efficacy of multi-pass spray aeration treatment to remove trihalomethanes (THMs) and to reduce the total THM formation potential (TTHMFP) of an aerated water...
Show moreThis dissertation reports on research related to novel water treatment and monitoring techniques for sulfide-laden groundwater supplies. The dissertation is divided into several chapters with four core chapters focused on investigations studying a novel water treatment method or monitoring technique. The first investigation assessed the efficacy of multi-pass spray aeration treatment to remove trihalomethanes (THMs) and to reduce the total THM formation potential (TTHMFP) of an aerated water column post-aeration. A recirculating spray aeration pilot unit was constructed to make this assessment. To assess the effect of multi-pass spray aeration on the TTHMFP, water was recirculated through a fabricated spray nozzle for various lengths of time. Results showed that multi-pass spray aeration can remove chloroform, dichlorobromomethane, dibromochloromethane and bromoform to below detection levels ((<) 0.7 ppb) for the waters investigated. Additionally, spray aeration reduced the TTHMFP of chlorinated water. Results suggest multi-pass spray aeration may be a viable treatment option for some bromide container waters. Results also indicate that multi-pass spray aeration removes bromide from the bulk water in the form of organically bound volatile compounds.The second investigation assessed the efficacy of using pre-existing tray aeration infrastructure to comply with disinfection by-product (DBP) regulations. To assess the efficacy of tray aerators to reduce the concentration TTHMs a pilot tray aerator was constructed. Results showed that after five tray passes (each pass consisting of water being passed over five trays) the concentration of TTHMs was below the detection limit ((<) 0.7 ppb) for the water investigated. To assess the efficacy of tray aeration at full-scale, a water treatment plant and the distribution system it serves were monitored for eight months. Results showed an approximate 40 ppb reduction in the TTHM concentration at two on-site monitoring locations and the one off-site monitoring location (initial concentrations being approximately 54 ppb, 60 ppb and 73 ppb, respectively). Results suggest that the utility managing the full-scale system could comply with DBP regulations by using the pre-existing tray aeration infrastructure to reduce formed THMs on-site where regulated haloacetic acids are not predominant.The third investigation assessed the efficacy of using biological activated carbon (BAC) to remove disinfection by-product precursor matter to comply with DBP regulations. To research this method, a pilot scale BAC filter was operated for three independent test runs. In addition, two full-scale WTPs using BAC were monitored over time. Results showed an approximate 40 percent removal of dissolved organic carbon (DOC) during the three pilot runs and an approximate 55 percent removal of DOC during full-scale monitoring. Results showed that the reduction in DOC reduced the TTHMFP of BAC treated water. Results suggest that BAC treatment could be a viable treatment option to comply with DBP regulations in the sulfide-laden water studied.The fourth investigation assessed the suitability of oxidation reduction potential (ORP) to monitor the effectiveness of an oxidizing media filter used to remove sulfur from a sulfide-laden groundwater. Results showed that ORP was more useful as a measurement technique as compared to free chlorine residual when assessing filter bed health and regeneration effectiveness. It was determined that when the ORP measurement taken from within the oxidative media layer was below 500 mV, the filter bed was not providing treatment, and manganese could be released. Results showed a significant increase in turbidity ((>) 2 NTU) and total manganese ((>) 0.05 mg/L) occurred when the ORP within the filter bed dropped below 400 mV. More frequent cycling of the filters was found to be an effective treatment option to maintain ORP values above an identified 400 mV operational threshold.
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Date Issued: 2017
Identifier: CFE0007141, ucf:52317
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007141

Title: Ozone and GAC Treatment of a Central Florida Groundwater for Sulfide and Disinfectant By-Product Control.
Creator: Lamoureux, Tara, Duranceau, Steven, Randall, Andrew, Wang, Dingbao, University of Central Florida
Abstract / Description: This study evaluated the combination of ozone and granular activated carbon (GAC) treatment for the removal of sulfide and disinfection byproduct (DBP) precursors in drinking water at the pilot-scale. The research conducted was performed at the Auxiliary (Aux) and Main Water Treatment Plants (WTPs) in Sanford, Florida. Both WTPs rely upon groundwater sources that contain total sulfide ranging from 0.02 to 2.35 mg/L and total organic carbon (TOC) ranging from 0.61 to 2.20 mg/L. The Aux WTP's...
Show moreThis study evaluated the combination of ozone and granular activated carbon (GAC) treatment for the removal of sulfide and disinfection byproduct (DBP) precursors in drinking water at the pilot-scale. The research conducted was performed at the Auxiliary (Aux) and Main Water Treatment Plants (WTPs) in Sanford, Florida. Both WTPs rely upon groundwater sources that contain total sulfide ranging from 0.02 to 2.35 mg/L and total organic carbon (TOC) ranging from 0.61 to 2.20 mg/L. The Aux WTP's raw water contains, on average, 88% more sulfide and 24% more TOC than the Main WTP. Haloacetic acids (HAA5) and total trihalomethanes (TTHMs) comprise the regulated forms of DBPs. HAA5 are consistently below the maximum contaminant level (MCL) of 60 ?g/L, while TTHM ranges from 70 to 110 ?g/L, at times exceeding the MCL of 80 ?g/L in the distribution system. Ozone alone removed total sulfide and reduced UV-254 by about 60% at the Aux Plant and 35% at the Main Plant. Producing an ozone residual of 0.50 mg/L prevented the formation of bromate while removing approximately 35 to 60% concentration of DBP precursors as measured by UV-254. Operating the GAC unit at an empty bed contact time (EBCT) of 10 minutes for the Aux Plant and 5.5 minutes for the Main Plant resulted in 75% and 53% of UV-254 reduction, respectively. The average 120 hour TTHM formation potential for the Aux and Main Plants were 66 ?g/L and 52 ?g/L, respectively, after treatment by ozone and GAC. GAC exhaustion was deemed to have occurred after seven weeks for the Aux Plant and eleven weeks for the Main Plant. The GAC columns operated in three phases: an adsorption phase, a transitional phase, and a biologically activated carbon (BAC) phase. The GAC adsorption phase was found to produce the lowest TTHMs; however, TTHMs remained less than 80 ?g/L during the BAC stage at each plant. BAC exhaustion did not occur during the course of this study. Ozone-GAC reduced chlorine demand by 73% for the Aux Plant and 10% for the Main Plant.
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Date Issued: 2013
Identifier: CFE0004708, ucf:49824
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004708

Title: A NEW PARADIGM OF MODELING WATERSHED WATER QUALITY.
Creator: Zhang, Fan, Yeh, Gour-Tsyh, University of Central Florida
Abstract / Description: 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.
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Date Issued: 2005
Identifier: CFE0000448, ucf:46405
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000448

groundwater (6)	+ -
Groundwater (5)	+ -
groundwater depletion (2)	+ -
sinkhole (2)	+ -
Base flow recession (1)	+ -

Best Management Practices (1)	+ -
Biological Filtration (1)	+ -
Biological Treatment (1)	+ -
Budyko (1)	+ -
Cations (1)	+ -
Climate change (1)	+ -
East-central Florida (1)	+ -
Environmental Sensing (1)	+ -
Eutrophication (1)	+ -
Fast/ Equilibrium Reactions (1)	+ -
Finite Element Method (1)	+ -
Fully-implicit (1)	+ -
GRACE (1)	+ -
Groundwater Velocity (1)	+ -
Groundwater modeling (1)	+ -
HFNF (1)	+ -
High Plains Aquifer (1)	+ -
Kinetic-Variable (1)	+ -
LC/MS-MS (1)	+ -
Lagrangian-Eulerian approach (1)	+ -
Low Velocity (1)	+ -
Modeling (1)	+ -
Monitoring (1)	+ -
Mosaic's sinkhole (1)	+ -
NOM (1)	+ -

University of Central Florida (17)	+ -
Wang, Dingbao (8)	+ -
Duranceau, Steven (7)	+ -
Sadmani, A H M Anwar (5)	+ -
Lee, Woo Hyoung (4)	+ -

Nam, Boo Hyun (4)	+ -
Chopra, Manoj (3)	+ -
Singh, Arvind (3)	+ -
Clausen, Christian (2)	+ -
Medeiros, Stephen (2)	+ -
Randall, Andrew (2)	+ -
Yun, Hae-Bum (2)	+ -
Alrowaimi, Mohamed (1)	+ -
An, Jin Woo (1)	+ -
Arenas Daza, Maria (1)	+ -
Bohlen, Patrick (1)	+ -
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Engineering (1)	+ -
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