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Your search for ETD Program Environmental Engineering resulted in 12 match(es).

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Impact of a Model Soil on the Biotransformation of 2,4,6-Trinitrotoluene and its Amine Metabolites: Author: Walker, Diane Kathryn; Date: 2004-05-15; Program: Environmental Engineering; Abstract: The end of the Cold War resulted in the closure of many sites where explosives were manufactured, processed, and stored, and packaging practices left behind highly contaminated surface waters, groundwater and soils. Chief among the explosives contaminating these sites is the xenobiotic, 2,4, 6- trinitrotoluene (TNT) whose electron-withdrawing nitro-groups make this aromatic compound highly resistant to biodegradation. An alternative option to mineralization as a bioremediation strategy, however, is immobilization. TNT can be biotransformed under reducing conditions to 2,4,6-triaminotoluene (TA...; Download File | View full details

Kinetics and Community Profiling of Sulfate-Reducing Bacteria in Organic Carbon Treated Mine Tailings: Author: McBroom, Mark David; Date: 2005-05-15; Program: Environmental Engineering; Abstract: Acid rock drainage (ARD) poses a significant health and Environmental hazard worldwide via the discharge of highly acidic waters and potentially toxic levels of mobile metals. This is a result of weathering and microbial oxidation of pyretic minerals present in mine tailings. Sulfate reducing bacteria (SRB), which are often indigenous to mine tailings, have demonstrated promising potential in metabolically raising effluent pH and immobilizing metals through precipitation and biomineralization. The addition of an organic carbon source has the potential of stimulating the SRB and reducing ARD at...; Download File | View full details

A Microbial Fuel Cell using Biomineralized Manganese Oxides as a Cathodic Reactant: Author: Rhoads, Allison Nicole; Date: 2005-05-15; Program: Environmental Engineering; Abstract: Microbial fuel cells were designed and operated utilizing microorganisms in both the anodic and cathodic compartments. In the cathodic compartment we used Leptothrix discophora because of the microorganism's capability to deposit biomineralized manganese oxides on the electrode. Biomineralized manganese oxides are superior to oxygen when used as a cathodic reactant. In the anodic compartment of most of the fuel cells we oxidized glucose using Klebsiella pneumoniae. In one fuel cell we used Desulfovibrio desulfuricans, a sulfate reducing bacteria. Electrons released in the anodic compartment, ...; Download File | View full details

Power Management for Microbial Fuel Cells: Author: Shantaram, Avinash; Date: 2005-05-15; Program: Environmental Engineering; Abstract: Monitoring parameters characterizing water quality, such as temperature, pH and concentrations of heavy metals in natural waters, is often followed by transmitting the data to remote receivers using telemetry systems. Such systems are commonly powered by batteries, which can be inconvenient at times because batteries have a limited lifetime and have to be recharged or replaced periodically to ensure that sufficient energy is available to power the electronics. To avoid these inconveniences, we have designed and tested a self-renewable power source, a microbial fuel cell, which has the potentia...; Download File | View full details

Structure and Activity of Pseudomonas aeruginosa PAO1 Biofilms: Author: Angathevar Veluchamy, Raaja Raajan; Date: 2006-05-15; Program: Environmental Engineering; Abstract: Nutrient concentration profiles are affected by the mass transport outside the biofilm, inside the biofilm, and by the structure of the biofilm. To understand the distribution of biofilm activity, it is necessary to correlate the local nutrient concentration, local mass transport in the biofilm and the biofilm structure. The correlations among surface averaged dissolved oxygen concentration, surface averaged relative effective diffusivity, and areal porosity in the biofilms of Pseudomonas aeruginosa PAO1 grown in a flat plate reactor, were quantified. Three dimensional distributions of local d...; Download File | View full details

Retention of a Model Pathogen in a Porous Media Biofilm: Author: Bauman, Wesley James; Date: 2007-05-15; Program: Environmental Engineering; Abstract: The inadvertent or deliberate introduction of bacterial pathogens into drinking water systems can lead to serious public health consequences. As a result, rapid sampling opportunities within distribution systems are needed that can provide information on the source, species and fate of introduced pathogens. In this study, a porous media biofilm reactor was used to investigate the ability of an established mixed-species drinking water biofilm to immobilize cyan-labeled Escherichia coli 0157:H7 as a model pathogen. Test reactors were colonized with biofilm for two or three weeks at 0.5 mg/l C, r...; Download File | View full details

Pathogen Transport and Capture in a Porous Media Biofilm Reactor: Author: Grabinski, Kevin John; Date: 2007-08-15; Program: Environmental Engineering; Abstract: Drinking water distribution systems pose the potential to transport biological and chemical contaminants to the consumers' tap that can be responsible for widespread waterborne disease outbreaks (WBDO). A need exists to improve the ability to monitor contaminants that can attach to the distribution system's interior surfaces and to obtain samples for diagnosing both the cause of a WBDO and the extent of contamination within the system. In this study, a porous media reactor colonized with a mixed-species drinking water biofilm was used to study the capture of Salmonella typhimurium as a model...; Download File | View full details

Influence of Pollutant Loading Rate on Seasonal Performance of Model Constructed Wetlands: Author: Schultz Jr, Rickey Lynn; Date: 2007-12-15; Program: Environmental Engineering; Abstract: Constructed wetlands (CW) are a viable alternative wastewater treatment technology for many wastewater types. However, recommended loading rates vary widely between regulatory agencies. A greenhouse experiment was carried out for approximately 19 months to study the effect of loading rate, plant species selection, temperature and season on pollutant removal in bench-scale constructed wetlands. The wetlands were operated in batch mode at batch lengths of 3, 6, and 9 days, corresponding to loading rates of 210, 105, and 70 kg COD/ha·d, respectively. Greenhouse temperature cycled fr...; Download File | View full details

Quantifying the viscoelastic properties of treated and untreated Pseudomonas aeruginosa and Staphylococcus epidermidis biofilms using a rheological creep analysis: Author: Sutton, Michael Philip; Date: 2008-05-15; Program: Environmental Engineering; Abstract: Microbial biofilms are quite difficult to kill and control, and present many problems to industry and medicine. The ability to alter the mechanical properties of biofilms could aid in the control of biofilm. The goal of this research project was to develop techniques for measuring the mechanical properties of biofilms so that the effects of chemical treatments could be assessed. Constitutive material models were developed and applied to assist in this effort to quantify the effects. Biofilms are viscoelastic in nature, therefore, rheological testing techniques were utilized for this research. ...; Download File | View full details

Breakthrough of indicator organisms from slow sand filters as part of a drinking water production system for Sub-Saharan Africa: Author: Ba, Sidy; Date: 2008-05-15; Program: Environmental Engineering; Abstract: Sub-Saharan Africa has the lowest proportion of population in the world with access to potable water, so that there is a dire need for low-cost, low-energy robust treatment technologies for drinking water. Constructed wetlands followed by optimized slow sand filtration has the potential for improving raw surface water quality to an acceptable level. A laboratory study examined the removal of Enterococcus durans and Environmental coliforms with associated heterotrophic bacteria from slow sand columns operating with different sand sizes and flow conditions. E. durans removal far exceeded 90% in ...; Download File | View full details

Hydraulic model calibration for the Girdwood, Alaska water distribution system: Author: Trasky, Trevor Ryan; Date: 2008-05-15; Program: Environmental Engineering; Abstract: The possible EPA promulgation of regulations requiring flushing programs for water distribution systems to regulate water age is encouraging many utilities to develop a better understanding of their systems. This usually involves the development of a hydraulic model. For the hydraulic model to be of use it must be calibrated using collected field data. Few established guidelines exist for utilities to perform such data collection and calibration. There are many different types of data that can be collected using many different methods. There are also various model calibration methods that can ...; Download File | View full details

Nitrification in premise plumbing systems: Author: Rahman, Mohammad Shahedur; Date: 2008-08-15; Program: Environmental Engineering; Abstract: Monochloramine is increasingly used instead of free chlorine as a secondary disinfectant. Ammonia is introduced into water for monochloramine formation or by decay. Nitrification can have deleterious effects on water quality that may lead to regulatory violations. In this project water quality and influence of pipe material on the onset of nitrification and consequences of nitrification in premise plumbing were investigated. Also potential control strategies for nitrification were evaluated. Initially two types of copper coupons (new and old, i.e., pre-exposed to 0.1N NaOH solution) were used ...; Download File | View full details

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