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Air Force Institute of Technology

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Articles 121 - 150 of 185

Full-Text Articles in Environmental Engineering

Optimal Pulsed Pumping For Remediation Of Aquifers When Sorption Is Rate-Limited, Lawrence J. Schmitt Dec 1997

Optimal Pulsed Pumping For Remediation Of Aquifers When Sorption Is Rate-Limited, Lawrence J. Schmitt

Theses and Dissertations

A variational optimization technique is developed to acquire an optimal schedule of pulsed pumping operations for use at existing pump-and-treat aquifer remediation sites. The optimization problem is stated as a minimization of a generic management objective functional, constrained by the contaminant transport equations in two-dimensional or three-dimensional flow models which account for rate-limited sorption. The two-dimensional case is fully developed and a first-order rate equation is used to describe the transport of sorbing contaminant. The first variation provides necessary optimality conditions that must be met by any optimal solution, in turn leading to a pulsed pumping schedule of operation. The …

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Modeling Uptake And Translocation Of Lead (Pb) In Maize For The Purposes Of Phytoextraction, Mark A. Brennan Dec 1997

Modeling Uptake And Translocation Of Lead (Pb) In Maize For The Purposes Of Phytoextraction, Mark A. Brennan

Theses and Dissertations

Phytoextraction is a remediation technology that uses plants to remove heavy metals from soil. This technology has the potential to decrease the costs of remediating contaminated sites by several orders of magnitude compared to traditional technologies. To effectively implement this technology requires an understanding of the plant processes that control uptake and translocation of metals from the soil. Currently these processes are poorly understood, and especially so for Pb. The purpose of this thesis was to gain insights concerning the plant mechanisms that control uptake and translocation of Pb and how these mechanisms interact to control levels of Pb accumulation …

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A Modeling Study For The Implementation Of In Situ Cometabolic Bioremediation Of Trichloroethylene-Contaminated Groundwater, John A. Christ Dec 1997

A Modeling Study For The Implementation Of In Situ Cometabolic Bioremediation Of Trichloroethylene-Contaminated Groundwater, John A. Christ

Theses and Dissertations

The limitations of conventional groundwater remediation technologies have led to the development of innovative technologies which may achieve national hazardous waste site remediation goals. Before an innovative technology can be implemented in the field, remedial project managers, regulators and other stakeholders require adequate modeling tools to help assess the applicability of the technology at a particular site. This modeling study investigates how an innovative technology, in situ cometabolic bioremediation, might be implemented to remediate a TCE-contaminated site, under different site conditions. A steady-state model is developed which couples an analytical expression to simulate the effect of flow between multiple pumping …

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Mobilization Of Trace Elements In Aquifers By Biodegradation Of Hydrocarbon Contaminants, Scott L. Kearney Dec 1997

Mobilization Of Trace Elements In Aquifers By Biodegradation Of Hydrocarbon Contaminants, Scott L. Kearney

Theses and Dissertations

This study had two objectives: (1) to determine the extent of metal mobility within petroleum-contaminated aquifers, (2) to determine if biodegradation of petroleum hydrocarbons can explain metal mobility. The approach reviewed analytical results from 2305 groundwater sampling events, taken from 958 wells, located at 136 sites found at 53 Air Force installations. The study showed that high levels of metals are present at petroleum hydrocarbon sites where metals would not generally be expected. Of the metals with drinking water maximum contaminant levels (MCLs), mercury and silver were detected the least frequently. Barium and copper were detected at the sites, but …

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A Cercla-Based Decision Model To Support Remedy Selection For An Uncertain Volume Of Contaminants At A Doe Facility, Christine E. Kerschus Dec 1997

A Cercla-Based Decision Model To Support Remedy Selection For An Uncertain Volume Of Contaminants At A Doe Facility, Christine E. Kerschus

Theses and Dissertations

The Paducah Gaseous Diffusion Plant (PGDP) operated by the Department of Energy is challenged with selecting the appropriate remediation technology to cleanup contaminants at Waste Area Group (WAG) 6. This research utilizes value focused thinking and multi attribute preference theory concepts to produce a decision analysis model designed to aid the decision makers in their section process. The model is based on CERCLA's five primary balancing criteria, tailored specifically to WAG 6 and the contaminants of concern, utilizes expert opinion and the best available engineering, cost, and performance data, and accounts for uncertainty in contaminant volume. The model ranks 23 …

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Evaluation Of The Natural Biodegradation Of Aircraft Deicing Fluid Components In Soils, Laura M. Johnson Dec 1997

Evaluation Of The Natural Biodegradation Of Aircraft Deicing Fluid Components In Soils, Laura M. Johnson

Theses and Dissertations

This research effort was conducted to analyze the biodegradation of propylene glycol (PG) and tolyltriazole in two different soil types; a sandy soil and a high clay soil. Both an automated respirometer and a high performance liquid chromatograph (H PLO) were used in the analysis. Two separate experiments were conducted. In the first experiment, one level of tolyltriazole was added to the soils to determine whether or not there was a difference in the biodegradation rates of tolyltriazole in the two soils. The respirometer results indicated that there was a significant difference between the respiration rates of the microorganisms in …

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Metabolic Inhibition Of A Toluene-Enriched Microbial Population Due To Lead (Pb2+): Verification Of A Free Metal Ion Toxicity Model, Patrick J. S. Marbas Dec 1997

Metabolic Inhibition Of A Toluene-Enriched Microbial Population Due To Lead (Pb2+): Verification Of A Free Metal Ion Toxicity Model, Patrick J. S. Marbas

Theses and Dissertations

A dissolved oxygen probe and an ion specific electrode were used to study the lead-induced metabolic inhibition in a toluene-enriched microbial population. Predicted toxicity values were compared to the actual toxicity responses using a free metal ion toxicity model (TM) which linked metabolic inhibition with lead activity. Experimentally derived values for the model parameters (lead activity and a lead distribution coefficient) were used in the TM. It was postulated that cellular metabolism is disrupted by the conformational changes to the cell's plasma membrane produced by lead ion adsorption. The predicted toxicity values were higher than the actual toxicity response. This …

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Department Of Defense Hazardous Waste Site Remediation Issues In The Republic Of Korea, Edwin H. Oshiba Dec 1997

Department Of Defense Hazardous Waste Site Remediation Issues In The Republic Of Korea, Edwin H. Oshiba

Theses and Dissertations

The purpose of this research was to provide information to DoD decision makers regarding factors influencing hazardous waste site remediation policy for South Korea. This study addressed: International agreements and U.S. and South Korean laws and policies relevant to hazardous waste sites; objectives of DoD environmental policy makers; extent and effects of soil and groundwater contamination; cleanup precedents set in other foreign countries; availability of resources and technical capabilities to investigate and remediate hazardous waste sites in South Korea; and opportunities for cooperation between the U.S. and South Korean military with regard to hazardous waste site remediation. Data were collected …

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Investigation Of Biodegradation Processes In Solid Waste Landfills, Philip A. Colborn Dec 1997

Investigation Of Biodegradation Processes In Solid Waste Landfills, Philip A. Colborn

Theses and Dissertations

Greater demands on landfill capacity, stricter regulations intended to minimize landfill environmental impacts, and the economic potential associated with landfill operations have shifted the emphasis of landfill disposal toward methods concerned with the long term performance and capacity of landfills. Two opposing philosophies have emerged in constructing and managing landfills: the dry tomb and the wet cell. The key to managing a landfill from the wet cell viewpoint is first understanding the biodegradation processes occurring within the landfill. This thesis attempts to determine the fundamental processes responsible for the degradation of solid waste by employing a system dynamics approach. A …

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Biodegradation Of Deicing Agents In Various Soil Types, Annmarie Halterman-O'Malley Dec 1997

Biodegradation Of Deicing Agents In Various Soil Types, Annmarie Halterman-O'Malley

Theses and Dissertations

Airports have found that spent deicing fluids eventually reach the airfield's stormwater system and soil surrounding the airfield. Due to toxic effects of spent deicing fluids, containing and collecting the fluid for treatment can be a very costly activity for airports. One alternative to dispose of the used deicing fluid is to institute a land treatment system if it can be proven that the deicing fluid is readily biodegradable in a soil system. The primary concern of this research effort was to monitor the behavior of a simulated aircraft deicing fluid in various soil systems. An automated respirometer monitored the …

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An Examination Of Elements Necessary For Transfer Of An Environmental Remediation Technology From Full-Scale Demonstration To Implementation, Glenn C. Mandalas Dec 1997

An Examination Of Elements Necessary For Transfer Of An Environmental Remediation Technology From Full-Scale Demonstration To Implementation, Glenn C. Mandalas

Theses and Dissertations

The fact that an innovative environmental remediation technology has been proven feasible in a full scale evaluation does not assure that the technology will be implemented. A number of regulatory, economic, and institutional barriers may impede the transition of a remediation technology from full scale demonstration to implementation. This research explores these barriers, suggesting means to overcome them. Regulators, technology users, and other remediation decision makers apply the nine criteria specified in the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) to evaluate the applicability of an innovative remediation technology at uncontrolled hazardous waste sites. These criteria consider such things …

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A System Dynamics Model Of The Bioavailability Of Metals In Constructed Wetland Sediment, Timothy S. Wood Dec 1997

A System Dynamics Model Of The Bioavailability Of Metals In Constructed Wetland Sediment, Timothy S. Wood

Theses and Dissertations

Constructed wetlands used for storm water treatment accumulate metals primarily in their sediment. This sediment has the potential to produce toxic effects in benthic organisms at some period in time. Bioavailability of metals in sediment is directly linked to pore water metal activity. The mechanisms that influence pore water metal activity are included in physical, chemical, and biological processes. A system dynamics model was developed to represent these processes and the major influences affecting pore water metal activity in a treatment wetland receiving storm water influent. The model structure and behavior was tested and validated using several system dynamics validation …

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A Comparative Analysis Of Two Alternatives To Chemical Aircraft Paint Stripping, George P. Joyce Ii Dec 1996

A Comparative Analysis Of Two Alternatives To Chemical Aircraft Paint Stripping, George P. Joyce Ii

Theses and Dissertations

The Air Force must periodically strip and paint its aircraft to prevent the damaging effects of corrosion. The paint removal process typically involves the use of toxic chemicals such as methylene chloride which are soon to be banned as a result of impending environmental regulations and increased costs associated with handling and disposing of such material. The Air Force must choose an alternative to methylene chloride chemical stripping which complies with environmental regulations and reduces costs. This thesis compares the life cycle costs and environmental impacts of two alternatives to chemical aircraft stripping. Plastic Media Blasting (PMB) and Modified Medium …

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Study Of Desorption Of Contaminant From Synthetic Soil, Kung-Fu Hwang Dec 1996

Study Of Desorption Of Contaminant From Synthetic Soil, Kung-Fu Hwang

Theses and Dissertations

A better understanding of sorption and desorption processes could improve estimates of time and cost required for remedial activities, exposure times and health risk, and bioavailability. Conventional rate-limited sorption models do not accurately define the diffusion domain at the grain scale. Heyse (1994) proposed the multiple sites in series (MSS) model, which allows more general description of the geometry of the sorption domain than the classical spherical or discrete distributions. A version of this model was tested by deVenoge (1996). The model was able to accurately simulate sorption rate data, but could not estimate unique geometry parameters. This research is …

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Investigation Of Sorption Mass Transfer Models Using Synthetic Soils, Karla K. Mika Dec 1996

Investigation Of Sorption Mass Transfer Models Using Synthetic Soils, Karla K. Mika

Theses and Dissertations

Grain-scale sorption mass transfer is an important process that must be considered when predicting clean-up time and choosing remediation techniques for subsurface hazardous waste contamination. Rate-limited sorption is responsible for the rebound effect, where remediated groundwater is recontaminated by desorption. Sorbed contaminants are not available for microbial degradation, and the desorption rate may govern the effectiveness of natural attenuation by biodegradation. Grain-scale sorption nonequilibrium is generally attributed to diffusive transport, either in SOM or in mineral micropores. Typically used sorption mass transfer models either fail to reproduce long-term slow desorption (first-order models), or are based on diffusion in assumed (often …

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Environmental Restoration Project, Peer Review Process Assessment, Paul A. Schantz Dec 1996

Environmental Restoration Project, Peer Review Process Assessment, Paul A. Schantz

Theses and Dissertations

Installation Restoration Program (IRP) projects often cost over $250 thousand, and projects over $1.5 million are common. To ensure these projects are risk based, technically sound, and cost effective, the Air Force instituted a peer review program in 1992. The objective of this research is to describe and analyze the peer review process. Through triangulation of data from interviews, observations, official and academic documents, and surveys, seven constructs were discovered: focus, agenda, facilitator, written preparation, oral presentation, team characteristics, and reviewer characteristics. A questionnaire was used to gather perceptions of peer review effectiveness--the criterion variable--and of the seven constructs. A …

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Development Of Synthetic Soils For Sorption Mass Transfer Model Validation, Thomas P. De Venoge Dec 1996

Development Of Synthetic Soils For Sorption Mass Transfer Model Validation, Thomas P. De Venoge

Theses and Dissertations

Existing sorption models often fail to describe grain scale sorption because of an inability to define the diffusion domain. A proposed improved model required testing to determine model validity. The testing method used a synthetic media of known geometry such that the distribution of sorption sites was known. Sorption rate data was obtained using batch experiments with the media. Data was used in comparison against model predicted rates. Fined sorption site distributions were compared to real distributions obtained by controlling sorbent geometries. Comparison determined model performance in fitting known distributions. The focus of this study was to (1) determine what …

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Modeling Plant Uptake Of Metal In Constructed Wetlands Supported By Experimentally Derived Uptake Rates, Michael B. Peake Dec 1996

Modeling Plant Uptake Of Metal In Constructed Wetlands Supported By Experimentally Derived Uptake Rates, Michael B. Peake

Theses and Dissertations

Many communities and Air Force installations are using constructed wetlands to filter trace metals from their stormwater runoff. Constructed wetlands are attractive to industry for runoff mitigation because they are relatively cheap to build and operate and require little or no energy for operation. The purpose of this research project is to develop quantitative concepts for understanding the dynamics of metal uptake in constructed wetland plants by constructing a system dynamics model supported by experimental observation and offer environmental managers a tool to simulate, under a broad range of conditions, long term wetland exposure to stormwater runoff contaminated with trace …

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Development Of Site Characterization Simulator Specifications, Jeffrey L. Heiderscheidt Nov 1996

Development Of Site Characterization Simulator Specifications, Jeffrey L. Heiderscheidt

Theses and Dissertations

The purpose of this study was to develop a tool for evaluating data quality when characterizing a potentially contaminated groundwater aquifer, and to provide a basis for developing a simulator to allow environmental managers and engineers to practice and learn about the site characterization process. Specifically, this study characterized the uncertainty, estimation block size, and cost for the various methods of determining the value of each geological, hydrological, and contaminant parameter necessary to characterize a site. Research entailed identifying site characterization objectives and identifying parameters necessary to obtain those objectives. Methods of estimating each parameter were identified, then research was …

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Decision Support Model For Municipal Solid Waste Management At Department Of Defense Installations, John F. Muratore Dec 1995

Decision Support Model For Municipal Solid Waste Management At Department Of Defense Installations, John F. Muratore

Theses and Dissertations

This research focuses on the development of a decision support model to identify the preferred strategy for managing municipal solid waste using the principles of decision analysis theory. The model provides an effective decision making tool to evaluate and compare different municipal solid waste management strategies. The users of this model, the Environmental Manager or decision maker at a given installation, can enter installation-specific waste stream characteristics, treatment and disposal costs, and material buy-back prices to determine the expected value for various alternative strategies. The strategy having the greatest expected value is considered the preferred alternative. In calculating the expected …

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In Situ Warming And Soil Venting To Enhance The Biodegradation Of Jp-4 In Cold Climates: A Critical Study And Analysis, Ricky D. Cox Dec 1995

In Situ Warming And Soil Venting To Enhance The Biodegradation Of Jp-4 In Cold Climates: A Critical Study And Analysis, Ricky D. Cox

Theses and Dissertations

Numerous bioremediation projects have proven effective in accelerating contaminant biodegradation by injecting oxygen into the vadose zone with a technique called bioventing. In cold climates, bioremediation is limited to the summer when soil temperatures are sufficient to support microbial growth. Laboratory studies directly correlate increased biodegradation rates with temperature. By raising soil temperatures, in situ jet fuel remediation can be accelerated which was shown by a bioventing project conducted in 1991 at Eielson AFB, Alaska, where three soil warming techniques were used. Two methods actively warmed the soil - warm water circulation and heat tape; the other passively warmed the …

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Comparison Of Gravel Substrate Vs Soil Substrate For The Construction Of An Experimental Fen, Carolyn S. Langley Dec 1995

Comparison Of Gravel Substrate Vs Soil Substrate For The Construction Of An Experimental Fen, Carolyn S. Langley

Theses and Dissertations

Under the Clean Water Act Section 404 of 1972 and 33 CFR 320-330 and 40 CFR 230 moderate the destruction of wetlands by the Air Force to make way for other uses. To obtain a permit for a design or construction project which affects a wetland, the Air Force must agree to create new wetlands, or replace lost wetland acreage through wetland creation or restoration. The Air Force is interested in building 'successful' wetlands as inexpensively as possible. It has been common practice to use hydric soil, which often had to be hauled in, as the substrate at the restored …

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A System Dynamics Approach To Modelling The Degradation Of Biochemical Oxygen Demand In A Constructed Wetland Receiving Stormwater Runoff, Leslie A. Mudgett Dec 1995

A System Dynamics Approach To Modelling The Degradation Of Biochemical Oxygen Demand In A Constructed Wetland Receiving Stormwater Runoff, Leslie A. Mudgett

Theses and Dissertations

The objective of this research was to develop a tool to aid the Air Force Environmental Manager in the identification of the design parameters of a constructed wetland system that may be optimized to provide a desired biochemical oxygen demand (BOD) removal efficiency during the treatment of Air Force stormwater runoff. The objective is achieved through the development and use of a system dynamics model which simulates the hydrological functions of a constructed wetland as well as the processes within the wetland responsible for degradation of BOD. Based on literature review, the primary mechanism responsible for the degradation of BOD …

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A Case Study Of The Environmental Impacts Of The Beddown Of The C-17 Globemaster Iii At Charleston Afb, Richard H. Houghton Jr. Dec 1995

A Case Study Of The Environmental Impacts Of The Beddown Of The C-17 Globemaster Iii At Charleston Afb, Richard H. Houghton Jr.

Theses and Dissertations

Unites States Air Force acquisition environmental planning has changed significantly since the passage of the National Environmental Policy Act in 1969. This research examined the role of environmental planning in weapon system acquisition. It focused on environmental planning performed for the C-17 Globemaster III prior to its beddown at Charleston Air Force Base. The case study of the C- 17 beddown included interviews, archival record reviews, and direct observations at the base. Evidence was collected to determine what environmental impacts occurred during the beddown. An environmental postaudit compared actual impacts with those predicted in environmental planning documentation. Impacts were analyzed …

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A Comparison Of Response Surface Methodology And A One-Factor-At-A-Time Approach As Calibration Techniques For The Bioplume-Ii Simulation Model Of Contaminant Biodegradation, Benjamin Shuman Dec 1995

A Comparison Of Response Surface Methodology And A One-Factor-At-A-Time Approach As Calibration Techniques For The Bioplume-Ii Simulation Model Of Contaminant Biodegradation, Benjamin Shuman

Theses and Dissertations

This thesis compared Response Surface Methodology (RSM) to the one-factor-at-a-time approach for calibrating the Bioplume-II simulation model of contaminant biodegradation. The MADE-2 data set from Columbus Air Force Base, Mississippi was used. The one-factor-at-a-time approach reduced the root-mean-squared (RMS) error for the flow to 0.921225 feet in a total of 36 runs of Bioplume-II. The RSM approach reduced the error criterion to 0.918875 in a total of 47 runs. The one-factor-at-a-time approach was unable to reduce the error below 67.1831 parts per billion (ppb) after 21 runs. The RSM approach reduced the RMS error to 67.0327 ppb after 47 runs. …

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Validation Testing A Contaminant Transport And Natural Attenuation Simulation Model Using Field Data, Steven J. Flier Dec 1995

Validation Testing A Contaminant Transport And Natural Attenuation Simulation Model Using Field Data, Steven J. Flier

Theses and Dissertations

This research extends the work begun by Enyeart (1994) which evaluated the process of intrinsic bioremediation, and which developed a model for predicting the velocity of an aerobic degradation front, as it traverses the length of a JP-4 contaminant plume. It is assumed this aerobic front will traverse the contaminant plume as dissolved oxygen is carried by the ground water through the sorption-retarded contaminant. The ultimate purpose of Enyeart's model is to use it to develop field guidance for assessing the feasibility of intrinsic bioremediation to restore petroleum-contaminated soils. After simulating intrinsic bioremediation many times with a spreadsheet model, results …

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Analysis Of Soil Vapor Extraction Expenses To Estimate Bioventing Expenses, Steven M. Loken Nov 1995

Analysis Of Soil Vapor Extraction Expenses To Estimate Bioventing Expenses, Steven M. Loken

Theses and Dissertations

An in-depth analysis of the expenses incurred with five soil venting petroleum remediation projects was accomplished. The data was obtained from receipts provided by a major United States petroleum refiner and distributor. Cost categories were designed that incorporated all costs and provided a method to analyze the data. The five cost categories used were: permits, equipment, management, utilities, and analysis. Further analysis showed trends and described the behavior of the costs related to remediation events. The relative percentile for each cost category was found to be consistent among the projects. Many costs were also found to be very linear throughout …

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Use Of Respirometry To Determine The Effect Of Nutrient Enhancement On Jp-8 Biodegradability, Christian T. Totten Nov 1995

Use Of Respirometry To Determine The Effect Of Nutrient Enhancement On Jp-8 Biodegradability, Christian T. Totten

Theses and Dissertations

The purpose of this study was to use respirometry to measure the impact of nutrient combinations or treatments on JP - 8 biodegradation under simulated fuel spill soil conditions. The study was designed observe one soil type at a constant fuel exposure level of 1% and a constant moisture of 60% of field capacity. Three experiments conducted were of two and three factor designs with potassium nitrate and sodium phosphate addition levels serving as two factors and fuel serving as a third factor in Experiments 1 and 2. Cumulative oxygen values obtained by the respirometer were assumed to be a …

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Groundwater Model Parameter Estimation Using Response Surface Methodology, Richard M. Cotman Mar 1995

Groundwater Model Parameter Estimation Using Response Surface Methodology, Richard M. Cotman

Theses and Dissertations

This thesis examined the use of response surface methodology (RSM) to estimate the parameters of a finite-element groundwater model. An existing two-dimensional, steady-state flow model of a fractured carbonate groundwater system in southwestern Ohio served as the calibration target data set. A Plackett-Burman screening design showed that only four of the ten hydraulic conductivity zones significantly contributed to the output of the finite-element model. Also, the effective porosity parameter did not significantly affect the model's output. Using only the four significant hydraulic conductivity parameters; four two-level, four-factor designed experiments were conducted to exploit the first-order response surface defined by a …

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Optimal Pulsed Pumping For Aquifer Remediation When Contaminant Transport Is Affected By Rate-Limited Sorption: A Calculus Of Variation Approach, Richard T. Hartman Sep 1994

Optimal Pulsed Pumping For Aquifer Remediation When Contaminant Transport Is Affected By Rate-Limited Sorption: A Calculus Of Variation Approach, Richard T. Hartman

Theses and Dissertations

The remediation of groundwater contamination continues to persist as a social and economic problem due to increased governmental regulations and public health concerns. Additionally, the geochemistry of the aquifer and the contaminant transport within the aquifer complicates the remediation process to restore contaminated aquifers to conditions compatible with health-based standards. Currently, the preferred method for aquifer cleanup pump-and-treat has several limitations including, the persistence of sorbed chemicals on soil matrix and the long term operation and maintenance expense. The impetus of this research was to demonstrate that a calculus of variations approach could be applied to a pulsed pumping aquifer …

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