Engineering Commons^™

The Effects Of Dissolved Oxygen Concentration And Biological Solids Retention Time On Activated Sludge Treatment Performance, Jack Joseph Parker

Masters Theses

A bench scale treatment system with dissolved oxygen (DO) control was used to determine the effects of DO concentration and biological solids retention time (BSRT) on treatment performance using the activated sludge process. The four reactors, operating at BSRTs of 20, 10, 5, and 2 days, were fed settled municipal wastewater collected from the Kuwahee wastewater treatment plant in Knoxville, TN. The DO was maintained at different set points in each reactor ranging from 4.0 to 0.2 mg/L.

Experimental results indicate that carbon treatment performance improved, on average, with increasing BSRT but DO had little effect on carbon oxidation. Sludge …

Arsenic Removal For Small Drinking Water Treatment Systems: A Multimedia Cd-Rom For Drinking Water Professionals, Greg A. Harrison

Masters Theses

This thesis, in conjunction with the accompanying CD-ROM, are intended to be used by small public water system operators, owners, regulators, and engineers as an educational tool for future compliance with a lowered Arsenic Maximum Contaminant Level (MCL). The CD-ROM is the third in a series of water treatment technology CDs that were created by a collaboration of Dr. R. Bruce Robinson, the University of Tennessee, and Dr. M. Robin Collins, the Water Treatment Technology Center, the University of New Hampshire. The CD-ROM includes multimedia tools such as video and photos, which will aid in the understanding of the included …

Predicting Thermodynamic And Transport Parameters For Metal Contaminant Sorption To Hydrated Metal Oxides In Aquatic Systems, Paras Trivedi

Dissertations

Hydrated oxides such as HAO,'HFO, goethite, and BA40 are prevalent in soils and sediments as discrete particles or as coatings. These microporous oxides have large surface areas and high affmity for metal ions, and hence they act as both a sink and a source for anthropogenically released metal contaminants. To better understand risks posed by metals in the environment and to develop effective waste management programs, mechanistic models are needed to accurately predict their fate in soils and sediments.

To achieve this objective, sorption of metal ions Sr, Cd, Zn, Ni, and Ca to these oxides were studied with macroscopic …

Stormwater Management In Tennessee: Guidelines To Preventative Maintenance Practices And Improvements, Jacob S. Chandler

Masters Theses

The management of urban stormwater runoff is an important issue throughout Tennessee as urban development keeps expanding. With the rise of urban development, there is an ever-growing need for urban stormwater management systems and facilities which are built to protect downstream property owners from potential flood damage as well as to manage and control the increased stormwater runoff. However well-designed a drainage system or facility might be, adequate maintenance is vital for it to function as intended by the design engineer.

This thesis was written to serve as a document that provides information needed to support an effective maintenance program …

Evaluation Of Alternatives For Hydraulic Design Of Bridges With Hec-Ras, William Wesley Peck

Masters Theses

On average, flooding causes over five billion dollars of damage and 99 fatalities per year in the United States alone. These ever-increasing numbers indicate a need for rigorous design procedures for any structures which exacerbate flood risk. The U.S. Army Corps of Engineers Hydraulic Engineering Center (HEC) has developed a computer program called River Analysis System, and more commonly referred to as HEC-RAS or RAS.

HEC-RAS is the best and most recent method for hydraulic design of bridges, and available documentation provides guidance for its use. The author is experienced in hydraulic design of bridges and has developed this thesis …

Data Analysis And Correlations For The Particulate Matter Continuous Emission Monitoring System Test Program At The Tsca Incinerator, James A. Calcagno, Iii

Masters Theses

A field study was conducted to evaluate the performance of three commercially available particulate matter (PM) continuous emission monitoring systems (CEMS) during 1999-2000 at the U.S. Department of Energy (DOE) Toxic Substance Control Act (TSCA) Incinerator located near Oak Ridge, Tennessee. The incinerator is permitted to treat mixed-waste, Resource Conservation Recovery Act (RCRA) hazardous and nonhazardous waste, and wastes containing polychlorinated biphenyls (PCB). The mixedwaste treated at the incinerator contains both low-level radioactive and hazardous chemical constituents. The air pollution control system of the incinerator utilizes Maximum Achievable Control Technology (MACT), which is comprised of a rapid quench, venturi scrubber, …

Adsorption Of Inorganic And Organic Ligands Onto Aluminum Hydroxide And Its Effect In Water Treatment, Peter Pommerenk

Civil & Environmental Engineering Theses & Dissertations

The inorganic anions fluoride, sulfate, and orthophosphate are ubiquitous substances in aqueous environments. These chemicals are also applied in drinking water treatment processes where fluoridation, coagulation with sulfate-based metal salts, or the use of passivating corrosion inhibitors or sequestering agents is practiced. If these ions are present at elevated levels in raw waters or added in the treatment train at points other than directly before entering a finished water reservoir, they can exert a negative influence on the removal of particles and natural organic matter.

Although the water chemistry of these inorganic ions seems to be well understood, their potential …

Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker

Theses and Dissertations

Subsurface contamination by industrial chemicals is one of the most prevalent and costly environmental problems facing the United States government. This contamination problem must be managed to protect human health and the environment. Two basic strategies are used to deal with subsurface contamination: source removal and contaminant containment. While much cost and performance data are available for individual technologies associated with each of these strategies, there have been very few studies that have examined the benefits of implementing source removal technologies in order to reduce contaminant containment (and hopefully total) costs. This study examines the tradeoff between extent of source …

A System Dynamics Approach To Modeling Temperature Effects In Solid Waste, David A. Jokinen

Theses and Dissertations

The amount of municipal solid waste discarded to landfills is continually increasing even with extensive recycling efforts. The need to understand the behavior of waste in landfills is increased due to the decreasing number of active landfills, communities' concern to the potential hazards associated with landfills, and companies or installations with landfills on-site need to understand landfill behavior comply with new legislation concerning design and detecting hazardous material movement of-site. This research is focused on increasing the understanding of landfill behavior by examining the effects of temperature in a landfill system. A system dynamics approach was used in this research …

A Model For Palladium Catalyzed Destruction Of Chlorinated Ethenes In Contaminated Groundwater, Christopher M. Stoppel

Theses and Dissertations

Groundwater contamination by chlorinated ethenes is a widespread environmental problem. Conventional remediation technologies have shortcomings that have prompted further research into the development of novel treatment technologies. A palladium/ alumina catalyst in the presence of dissolved molecular hydrogen (referred to hereafter as a PD/H₂ system) has been demonstrated to rapidly destroy chlorinated ethene contaminated groundwater. First-order kinetics have been used to model chlorinated ethene destruction in a PD/H₂ reactor. However, catalyst deactivation and regeneration are important processes that also need to be modeled in order to better understand their effect on treatment efficiency. This study presents a model …

Modeling Biodegradation Of Chlorinated Groundwater Contaminants Under Iron-Reducing Conditions Of A Constructed Wetland: A System Dynamics Approach, Max E. Johnson

Theses and Dissertations

The purpose of this study is to determine and explore the fundamental processes associated with biodegradation of chlorinated ethenes in iron-reducing conditions of a constructed wetland and to evaluate the impacts of changing conditions (both natural and engineer-controlled) on the system. The modeler uses a system dynamics approach to construct a model that represents behavior in the iron-reducing environment. The model incorporates hematite, a form of oxidized iron (Fe³⁺), as the electron acceptor in microbial biodegradation in the system. Vinyl chloride, cis-dichloroethene, and trans-dichloroethene are known to anaerobically degrade to carbon dioxide in the presence of oxidized iron. …

Chromate Content Bias As A Function Of Particle Size In Aircraft Primer Paint Overspray, David B. Novy

Theses and Dissertations

Spray painting operations using chromate-containing primer paints produce particles which may expose workers to strontium chromate. Chromate contains hexavalent chromium (Cr(VI)) which is a confirmed human carcinogen. It is suspected that the smaller particles contain disproportionately less Cr(VI) than larger particles. In order to determine if a bias in chromate content exists, paint particles were collected and separated based on particle size and the Cr(VI) concentration was determined. Aviation primer paint from the DeSoto and Deft companies was sprayed in a booth and seven-stage cascade impactors were used to separate particles.

Modeling Chlorinated Ethene Removal In The Methanogenic Zone Of Constructed Wetlands: A System Dynamics Approach, Randall L. Roberts

Theses and Dissertations

The purpose of this study is to gain understanding of the dynamics of the processes that degrade Perchloroethene (PCE) to ethene, within the confines of the methanogenic zone of a constructed wetland. A system dynamics modeling approach is used. This model is focused on determining conditions that will enhance contaminant degradation. The chemical and biological processes within the methanogenic zone of a wetland system are extremely complex and dynamic processes. The model is broken up into three simultaneous processes: dechlorination, methanogenesis, and fermentation. The system behavior of the methanogenic zone can be adequately described by the classical formulations of representative …

Decision Analysis Methodology To Evaluate Integrated Solid Waste Management Alternatives For A Remote Alaskan Air Station, Mark J. Shoviak

Theses and Dissertations

Eareckson Air Station (AS), a remote U.S. Air Force installation, faces the complex decision of selecting a new municipal solid waste (MSW) management strategy to replace its current non-compliant system. This research effort applies value-focused thinking and multiattribute preference theory to decision analysis techniques to produce a multiple-objective decision analysis model that captures all of the site's MSW goals, objectives, and concerns in order to facilitate the evaluation of MSW management strategies available. The model ranks 40 specific MSW management alternatives, which were developed in accordance with the decision-maker's assumptions and constraints, based on how well they meet Eareckson's overall …

Quantitative Validation Of A Model Of Chlorinated Ethene Natural Attenuation, Harold C. Young

Theses and Dissertations

Chlorinated ethenes are among the most prevalent groundwater contaminants at hazardous waste sites nationwide. In an attempt to manage the risks posed by these contaminants, while controlling costs, monitored natural attenuation (MNA) is being considered as a remediation strategy at many sites. MNA relies on naturally occurring physical, chemical, and biological processes in the subsurface to reduce the risk posed by the contamination. The implementation of MNA, however, requires a detailed understanding of these processes, and how they impact contamination at a particular site. One way to gain this understanding is through contaminant fate and transport modeling. In this study, …

Assessing The Economic Impact Of Aircraft Noise On Communities, Ithan B. Zimmer

Dissertations

The impact of aircraft noise on communities is complex and multi-dimensional. This matter cannot be resolved without careful analysis of a complex array of related problems and issues including the environment, the economy, and quality-of-life concerns of people living in proximity to airports or aircraft routes. The effects of community noise are widespread and varied. Impacts can include sleep and speech interference, activity interference, general annoyance, and property value decrease. In order to improve public policy and provide a foundation for additional research, it is imperative to establish the extent of a problem. Dollars are often the least common denominator …

Development And Application Of A Computer Simulation Tool For Ecological Risk Assessments, Haiyi Lu

Theses

In an effort to improve tools in ecological risk assessment (ERA), an ERA software tool was developed and applied. Based on a preliminary evaluation of existing ecorisk models, the relative deficiencies were identified and included the need for a user-friendly interface, an interactive database management system (DBMS), and a comprehensive evaluation of exposure pathways. In this research, Visual Basic (VB) 6.0 and Microsoft SQL server were selected for developing the Windows-based interface and local DBMS, respectively. For the exposure estimate, Yuma and Aberdeen Proving Grounds were identified as baseline ecosystems. Terrestrial and aquatic plant and animal receptor selection was based …

Optimization Of Nitrogen Removal In Sequencing Batch Reactor, Suppakit Poonyachat

Theses

Operating parameters for sequencing batch reactor have the influenceon each substrate concentration. Concentration profile changes as operationparameters are changed. The study was conducted to model the variationin effluent concentration from sequencing batch reactor. MLVSS and cycletime are the parameters that were varied. Concentration in Fill, React,and Settle Period were calculated by using kinetic equations.

The results can show that these parameters have effects on the concentrationprofile. The increase of MLVSS can lower the concentration of BOD andammonium concentration in React period. Increasing MLVSS can show thatmore substrate utilization and nitrification process occur more rapidly.Concentration of nitrate at the end of …