Engineering Commons^™

An Evaluation Of The Groundwater Microbial Community's Toluene Biogenesis Potential At A Site In Southeast Louisiana, Michael A. Griffin Jr.

LSU Master's Theses

The broad goal of the research described in this thesis was to better understand the potential for biological toluene production to occur in groundwater at a Superfund Site located in southeast Louisiana. Previous literature reported that bacterial isolates under laboratory test conditions and undefined microbial communities in anaerobic sludge digesters and seasonally stratified lakes can produce toluene biogenically. Most of the research reported on this subject previously, however, has been on systems in Europe and little research has been reported previously on such phenomena in North America.

In the research described here, studies were conducted utilizing groundwater from a Superfund …

Removal Of Sustained Casing Pressure By Gravity Displacement Of Annular Fluid, Efecan Demirci

LSU Master's Theses

Sustained Casing Pressure (SCP) is the undesirable casing head pressure of a well annulus that rebuilds when bled-down. As the conventional methods for SCP removal using rigs are expensive, there is a need for improvement. Annular intervention for replacing the fluid above the leaking cement with a heavier fluid to stop gas migration is a solution for SCP removal; however, previous attempts failed due to miscibility of injected fluids. Using hydrophobic heavy fluids for the purpose is a newly proposed technique to the technology. Potential of theoretically selected and produced immiscible heavy fluids are investigated in characterized annular fluids. A …

Modeling Foam Delivery Mechanisms In Deep Vadose-Zone Remediation Using Method Of Characteristics (Moc), Alireza Roostapour

LSU Doctoral Dissertations

This study investigates foam delivery mechanisms in vadose-zone remediation by using Method of Characteristics (MoC). In such applications, dry foams are introduced into a porous medium which is initially at low saturation of water (Sw) containing pollutants such as metals and radionuclides. For vadose-zone remediation processes to be successful, the injected aqueous phase should carry chemicals to react with pollutants and precipitate them for immobilization and stabilization purposes. Typical remediation techniques such as water and surfactant injections are not applicable, because of the concerns about downward migration. As a result, understanding foam flow mechanism in-situ is key to the optimal …

Studies Of Hydrophobic Organic Pollutant Interactions With Cyclodextrin: Implication For Groundwater Remediation, Heng Gao

LSU Doctoral Dissertations

Henry’s Law constants of several common, subsurface hydrophobic organic pollutants (HOPs) including trichloroethylene (TCE), perchloroethylene (PCE) and benzene, toluene, ethylbenzene and o-xylene (BTEX), were measured over a range of temperatures (35, 45, 55 and 65°C) and cyclodextrin (CD) concentrations (0, 10, 20, 50 and 100 g L-1). In aqueous CD solutions, Henry’s constant values decrease by a power law relationship with increasing CD concentration due to an apparent solubility enhancement caused by HOP partitioning to the hydrophobic cavity of CD molecules. The temperature dependence of air-water partitioning under the influence of CD was well described by the van’t Hoff equation …

Effects Of Capping On Biodegradation Of Organic Contaminants In Sediments, Eun Ju Lee

LSU Doctoral Dissertations

Sediment capping remains an effective remediation technique for contaminated sediments due to its capability to contain contaminants and provide a sound habitat for indigenous biota. This research investigated the effect of capping on biodegradation of organic contaminants in Anacostia River sediments using both experimental and modeling techniques. 14C–Phenanthrene mineralization was monitored under various redox conditions in Anacostia River sediments. Mineralization of 14C–phenanthrene was strongly linked to sulfate reduction, which was the more energetic process than any other anaerobic condition in Anacostia sediments. Sulfate is a more promising terminal electron acceptor for intrinsic degradation in Anacostia River and other PAH contaminated …

An In-Situ Capping Design For The Remediation Of Petroleum Contaminated Sediments, Melanie Krystle Harris

LSU Master's Theses

Historical disposal practices used by oil companies have caused the accumulation of contaminated sediments in their nearby lakes and ponds. These companies are now faced with the challenge of remediating the bodies of water that contain these contaminated sediments. The contaminants that remain in the sediment continue to pose a threat to human health and the environment. For example, high concentrations of polycyclic aromatic hydrocarbons (PAHs), which are still present in the bottom sediments can have toxic effects on aquatic life. One form of remediation for this problem is In-Situ Capping (ISC), which is defined as a method whereby material …