Civil and Environmental Engineering Commons^™

Modeling The Effect Of Nonlinear And Rate-Limited Sorption On The Natural Attenuation Of Chlorinated Ethenes, Peter P. Feng

Theses and Dissertations

Chlorinated solvents like tetrachloroethene (PCE) and trichloroethene (TCE) are the most common detected groundwater contaminants at Department of Defense installations in the United States. Unfortunately, technologies conventionally used to remediate chlorinated solvent-contaminated groundwater often fall short of achieving regulatory goals. Natural attenuation of chlorinated solvents offers an alternative remediation strategy that may achieve goals. However, the processes involved with natural attenuation are not fully understood, and this lack of understanding has hindered acceptance of natural attenuation by regulatory agencies. This study involved use of a numerical model that incorporated the physical, chemical, and biological processes thought to be relevant to …

Applicability Of Ozone In Small Drinking Water Systems, Craig D. Adams, Justin Sutherland

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of ozone in water treatment plants is expanding rapidly in the United States. Ozone offers excellent disinfection properties (including chlorine-resistant pathogens) and does not form trihalomethanes. Additionally, ozone can be used to achieve or control many other water quality parameters such as color, taste and odor, and inorganic and organic contaminant concentrations. Control of ozone's disinfection byproducts such as bromate (formed in high bromide waters) is required. This presentation will review the synergistic effects of ozone applicable to use in small water treatment plants.

Chemical Oxidation Of Mtbe Under O2-Rich And O2-Limited Environments Coupled With Biological Degradation Of Oxidation Byproducts, J. Sutherland, B. Panka, Craig D. Adams, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The H2O2/UV Advanced Oxidation Process (AOP) Was Investigated to Determine Byproduct Formation under Different Experimental Conditions (PH, Alkalinity, and H2O2/UV Dose). a Key Factor in the Efficiency of the AOP Was the Dissolved Oxygen Concentration. Gas Chromatography/mass Spectrometry (GC/MS) Analysis Was Used to Identify Byproducts Resulting from Oxidation under Oxygen-Rich and Oxygen-Limited Conditions. Resultant Oxidation Byproducts Were Analyzed for their Susceptibility to Biological Degradation. Biodegradation Rate Constants Were Determined and Modeled for the Primary Byproducts of the Advanced Oxidation Process. Inhibition Resulting from the Presence of Multiple Byproducts in a Biological System Was Investigated as Well. Effects of Process Parameters …

Soapbox: The Academic Research Fleet: An Exciting Time For Renewal, Larry Atkinson

CCPO Publications

(First Paragraph) Academic research ships in the United States are the envy of many scientists around the world. A great strength of our system is the diversity of ships and operators: users have a choice, the system can change. A weakness of the system is that very diversity: sometimes it is hard for us to act together. Nevertheless, we now must act together. The vitality of the academic fleet in the coming decades is at stake. The reason is simply because many of our ships, especially in the intermediate size range, will soon reach the end of their useful life.

Mathematical Modelling Of Road Bumps, E. S. Massawe

Tanzania Journal of Engineering and Technology (TJET)

In this paper, a general mathematical model that may be used for construction of a road bump on an inclined road is developed. It is shown that if the parameters for the inclination are set to zero, the resulting model reflects the special case of a flat road. Existing experiences are briefly highlighted and a case study was done on different locations along the University Road to demonstrate the developed model.

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …

Comparison Of One-Dimensional And Two-Dimensional Hydrodynamic Modeling Approaches For Red River Basin, Sajjad Ahmad, Slobodan P. Simonovic

Civil and Environmental Engineering and Construction Faculty Research

EXECUTIVE SUMMARY

A devastating flood in Red River valley in 1997 emphasized the need to study the flood control measures in the Red River basin using state of the art modeling tools. The Red River and its floodplains can be modeled using one-dimensional, quasi two-dimensional or fully two-dimensional hydrodynamic models. Each modeling approach has its own advantages and limitations. The main purpose of this report is a comparison between one-dimensional (or quasi two dimensional) and fully two-dimensional hydrodynamic modeling approaches for modeling floods in the Red River basin.

A two-dimensional hydrodynamic model, MIKE 21, coupled with Geographic Information System (GIS) …

Metadata In A Digital Special Library: The Energy And Environmental Information Resources Center In Lafayette, Louisiana, Dan Foley

E-JASL: Electronic Journal of Academic and Special Librarianship (1999-2009, Volumes 1-10)

This paper discusses three kinds of metadata and how they are used in the Energy & Environmental Information Resources Center (EE-IR Center), a digital special library of text, numeric, and geospatial data, located in Lafayette, Louisiana. These metadata are Dublin Core (DC), MARC21 (formerly USMARC), and Federal Geographic Data Committee (FGDC) metadata.

The EE-IR Center was formed as a partnership between the National Wetlands Research Center (NWRC) of the U.S. Geological Survey and the Center for Advanced Computer Studies of the University of Southwestern Louisiana (CACS/USL). Both partners are located in Lafayette, Louisiana. The EE-IR Center is funded by a …

Novel Carbon-Carbon Bond Oxidative Cleavage Of Hexabenzyl-Hexaazaisowurtzitane By N-Buono And (Nh4)2ce(No3)6, Xiao-Pei Guan, Hong Yan, Jian-Guang Sun, Yong-Zhong Yu

Publications and Research

Treatment of 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazatetracyclo-[5.5.0.05,9.03,11]dodecane with n-butyl nitrite or ammonium cerium nitrate results in novel C(1)-C(7) oxidative cleavage to give 1,3,4,5,7,8-hexabenzyl-cis-cisoid-cis-hexahydro-1H,5H-diimidazolinium[4,5-b:4′,5′-e]pyrazine dinitrate.

Estimating The Usle - Soil Erodibility Factor In Developing Tropical Countries:A Case Study In Tanzania, Metthew Mulengeral

Tanzania Journal of Engineering and Technology (TJET)

Developing countries in the tropics are facing more soil erosion problems than the developed temperate countries. These developing countries have no accurate locally applicable equation(s) for predicting soil erosion or for planning and implementation of soil conservation measures. Furthermore, These countries do not have the necessary resources to develop the soil loss prediction equation(s). Existing empirical equations like the Universal Soil Loss Equation (USLE) if modified to suit tropical conditions can be useful a tool in soil erosion control in the region for a foreseeable future. In this paper equations'for estimating the soil erodibility factor in the USLE for tropical …

Shoreline Change Modeling As A Tool In Coastal Environmental Management, Jorge Espinoza Amaguana

Civil & Environmental Engineering Theses & Dissertations

The one-line numerical model GENESIS has been calibrated to evaluate its performance as a tool in providing insights into the physical components to manage the coastal environment. To calibrate the model, physical environmental data, literature research, and computer modeling methodologies were utilized in addressing the objectives of this thesis. The model was applied at three beaches of the Virginia Beach City with different man-made structures by using the actual field wave data for wave year J 997. Waves are the main environmental component affecting the coastal system; however, additional environmental data and the best engineering decision were used as model …

Development And Evaluation Of A New Soil Erosion- Productivity Index Model (Sepim), Metthew Mulengera

Tanzania Journal of Engineering and Technology (TJET)

A soil erosion-productivity model which considers rhe effect of soil water storage Capacity. crop evapotranspiration, soil chemical and physical properties inrporrantfor Crop growth has been developed. The model is shown to give good predictions and it promises to be an improvement over the former productivity Index (PI). It also promises to give more reliable results than the currently used /nodels which consider only soil water storage capacity and crop e ' 'apotransp iration.

A Calibrated Shoreline Change Model For The Southeast Atlantic Ocean Coast Of Virginia, Prasert Vangsantitrakul

Civil & Environmental Engineering Theses & Dissertations

The idea that the long-term historic shoreline change at a given site is mainly caused by spatial gradients in the net longshore sediment transport is generally accepted. The position changes of the coastline can therefore be modeled by calculating the coastal erosion or accretion from the longshore sediment transport. This study used the GENESIS software program, one-line model, to simulate and calibrate the long-term shoreline change of the southeast coast of Virginia from 1925 to 1980. The study reach covers 45- km from Cape Henry to the Virginia-North Carolina border.

This study experienced the lack of certain important historic data …

Sparse Equation-Eigen Solvers For Symmetric/Unsymmetric Positive-Negative-Indefinite Matrices With Finite Element And Linear Programming Applications, Hakakizumwami Birali Runesha

Civil & Environmental Engineering Theses & Dissertations

Vectorized sparse solvers for direct solutions of positive-negative-indefinite symmetric systems of linear equations and eigen-equations are developed. Sparse storage schemes, re-ordering, symbolic factorization and numerical factorization algorithms are discussed. Loop unrolling techniques are also incorporated in the coding to enhance the vector speed. In the indefinite solver, which employs various pivoting strategies, a simple rotation matrix is introduced to simplify the computer implementation. Efficient usage of the incore memory is accomplished by the proposed "restart memory management" schemes. A sparse version of the Interior Point Method, IPM, has also been implemented that incorporates the developed indefinite sparse solver for linear …

Evaluation Of Toxicity, Bioavailability And Speciation Of Lead, Zinc And Cadmium In Mine/Mill Wastewaters, Mujde Erten-Unal, Bobby G. Wixson, Nord Gale, Jerry L. Pitt

Civil & Environmental Engineering Faculty Publications

The toxicity of common compounds of lead, cadmium and zinc was evaluated in waters similar to that found in the world's largest lead producing area in Missouri. Static, acute toxicity tests were performed using fathead minnows (Pimephales promelas) and water fleas (Daphnia magna) respectively. Test organisms were subjected to varying amounts of sulfide, carbonate, chloride and sulfate salts of lead, zinc and cadmium mixed in hard, alkaline waters typical to this region. Median lethal concentrations were calculated using nominal versus measured metal concentrations. Measured metal concentrations included four different metal fractionation (extraction/filtration) techniques at different pH …

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 …

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 …

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 …

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 …

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 …

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 …

The Study Of Wave-Blocking And Current Effects On Nonlinear Interactions Of Shallow-Water Waves Using Advanced Boussinesq Models, Qin Chen

Civil & Environmental Engineering Theses & Dissertations

The first part of this work focuses on the derivation of enhanced Boussinesq-type equations for the combined motion of waves and currents in shallow water areas.

The strategy proposed in this work is to couple two known methods which are the sponge layer concept suitable for short waves and Sommerfeld radiation condition for currents. This coupling method provides satisfactory non-reflective boundaries for the simulation of fully coupled wave/current motion as demonstrated by the numerical experiments. We verify the model against the well known solutions based on the existing theories and good agreement has been observed. The numerical results confirm the …

Specification And Verification Of Generic Cell Rate Algorithms In Pvs, Huseyin Ozgungor

Electrical & Computer Engineering Theses & Dissertations

Formal verification methods have been considered as a powerful complementary approach to define standards and to prove correctness of the systems. In this work, formal specification of Generic Cell Rate Algorithms are defined and proved. The specification process enables standardization for constructing Generic Cell Rate Algorithms. Standardization is an important process in the Asynchronous Transfer Mode (ATM) networks. By employing formal methods, the necessary standards could be constructed to allow different algorithms to be employed which still meet system requirements. Those system requirements are quantified in the Quality of Service (QOS).

Congestion management is a vital concept for networks in …

The Detoxification Of Petroleum Contaminated Coastal Plain Sandy Soil Using An Amended Vermicomposting Approach, John Charles Kraemer

Health Services Research Dissertations

This study explores the feasibility of utilizing an amended vermicomposting treatment approach for detoxifying petroleum hydrocarbon contaminated sandy soil. The bench-scale testing of gasoline and diesel contaminated soil using three test soil vessels and one control soil vessel was performed in a laboratory setting for a six week time period. The control soil received no treatment other than distilled water to maintain soil moisture. Treatment 1 consisted of direct application of liquid municipal biologic sludge on a weekly basis. Treatment 2 consisted of the addition of 30 Eisenia foetida earthworms and distilled water. Treatment 3 consisted of direct application of …

The River Association Approach To Privatization Of Federal Hydro Projects, Michael K. Block

Dams: Water and Power in the New West (Summer Conference, June 2-4)

15 pages.

Greener And More Equitable: A Vision For Dams And Other Western Water Issues, Bruce C. Driver

Dams: Water and Power in the New West (Summer Conference, June 2-4)

10 pages.

Contains 1 page of references.

The Future Of Western Water Developments, John Keys

Dams: Water and Power in the New West (Summer Conference, June 2-4)

9 pages.

Divestment Of Federal Water Projects, A. Jack Garner

Dams: Water and Power in the New West (Summer Conference, June 2-4)

21 pages.

Contains references.

River Management In The Twenty-First Century: The Vision Thing, A. Dan Tarlock

Dams: Water and Power in the New West (Summer Conference, June 2-4)

12 pages.

Contains references.

Of Dams And Salmon In The Columbia/Snake Basin: Did You Ever Have To Make Up Your Mind?, Don B. Miller

Dams: Water and Power in the New West (Summer Conference, June 2-4)

106 pages (includes illustrations and maps).

Contains 4 pages of references.