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Investigating Gulf Coast Aquifer System: Stratigraphy Reconstruction, Inverse Modeling, And Groundwater Stress Assessment, Shuo Yang

LSU Doctoral Dissertations

The Mississippi Embayment aquifer system (MEAS) and the Coastal Lowlands aquifer system (CLAS) provide substantial groundwater resources for human activities in the U.S. Gulf Coastal Plain. However, the overexploitation has led to groundwater depletion in the MEAS and the CLAS, threatening sustainable groundwater use. Such concern highlights the crucial need for an advanced understanding of stratigraphy and groundwater in these aquifer systems, which is essential for effective regional groundwater management. This dissertation presents a comprehensive investigation of MEAS and CLAS in the Louisiana and southwestern Mississippi region, encompassing three fundamental dimensions: stratigraphy reconstruction, groundwater modeling, and groundwater stress assessments. A …

Assessment Of Endogenous Biomass Decay As A Source Of Precursors For Microbially-Mediated Toluene And P-Cresol Production, Samuel J. Reynolds

LSU Master's Theses

The research reported in this thesis was conducted to investigate whether protein hydrolysis associated with endogenous decay of biomass produced following the addition of a readily fermentable substrate is a potential source of precursors that can ultimately be transformed to toluene and p-cresol in environments undergoing enhanced bioremediation.

A packed column intended to represent a laboratory-scale section of an aquifer was seeded with groundwater and then supplied with molasses-amended groundwater for a two-day interval. The injected molasses concentration and surface loading rate were selected to be representative of conditions in the vicinity of injection wells at a Superfund Site …

Model Development To Assess Groundwater Flooding And Levee Underseepage In New Orleans, Louisiana, Shuo Yang

LSU Master's Theses

Flooding is a major threat to New Orleans due to its geographic location and geologic condition. However, potential groundwater flooding is seldom studied and poorly understood even though groundwater level is expected high in the city. High groundwater level might result in groundwater flooding in low-lying areas. High uplift pore water pressures may cause strong underseepage and risk levee safety. The objective of this study is to assess the impacts of hydrogeology on groundwater flooding and evaluate potential underseepage-induced hazards along levees in New Orleans. In this study, a groundwater flow model development which involves stratigraphy modeling, groundwater flow model …

Investigation Of Subsurface Stratigraphy And Groundwater Dynamics In The Mississippi River Delta, An Li

LSU Doctoral Dissertations

The Mississippi River Delta (MRD) is socioeconomically important to the state of Louisiana and the United States. Various types of land-water system data have been collected in the MRD. However, very few efforts have been made to utilize these datasets in modeling regional stratigraphy and groundwater dynamics in the MRD, especially for the upper 50 m of the depth. In this interval of depth, the Mississippi River and surrounding interdistributary bays intensively interact with the groundwater system. The lack of knowledge in regional stratigraphy and groundwater dynamics hinder an understanding of how hydrogeological setting affects processes such as surface-groundwater interaction, …

Artificial Recharge Of Groundwater As A Management Tool For The Kabul Basin, Afghanistan, Mohammad Farid Masoom

LSU Master's Theses

Decades of war and political instability, consecutive droughts, population increase and displacement, caused serious infrastructural damages to water resources of Afghanistan. The main source of water supply for people in Afghanistan is groundwater. However, over-exploitation of groundwater has led to groundwater level declines in most parts of the country. Kabul, the largest city of Afghanistan, is the capital city with a population of 4.5 million and the fifth fastest-growing city in the world. The city has observed groundwater level declines of 5-10 meters (m) since 1980. Decline of about 30 m has also been observed in one of the monitoring …

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 …

Enhancing The Performance Of Anaerobic Bioreactors For The Biological Degradation Of Volatiles Organic Compounds In Groundwater Using Alternate Electron Acceptors, Leslie Michele Pipkin

LSU Doctoral Dissertations

Engineered anaerobic bioreactors (ABR) constructed from mixed media and sand can biodegrade high concentrations of volatile organic compounds (VOCs). Sustainable treatment of benzene, toluene, ethylbenzene, and xylenes (BTEX), chlorinated ethenes and ethanes were used to investigate the use of engineered ABRs, while also analyzing the system performance of a full-scale ABR system. Experimentations conducted on environmental and biological factors that affect ABR system performance was conducted through serum bottles, columns, and reactor studies.

Column and reactor ABR systems were designed to treat VOCs via biodegradation in groundwater with varying terminal electron acceptors (TEAs). Laboratory-scale column ABRs were constructed to treat …

Conjunctive Management Of Water Resources Under Climate Change Projection Uncertainty, Amir Mani

LSU Doctoral Dissertations

Goal of this study is to investigate the impacts of climate change projection uncertainty on conjunctive use of water resources. To pursue this goal first, a conjunctive-use model is developed for management of groundwater and surface water resources via mixed integer linear fractional programming (MILFP). The conjunctive management model maximizes the ratio of groundwater usage to reservoir water usage. A conditional head constraint is imposed to maintain groundwater sustainability. A transformation approach is introduced to transform the conditional head constraint into a set of mixed integer linear constraints in terms of groundwater head. A supply network is proposed to apply …

Bayesian Saltwater Intrusion Prediction And Remediation Design Under Uncertainty, Nima Chitsazan

LSU Doctoral Dissertations

Groundwater resources are vital for sustainable economic and demographic developments. Reliable prediction of groundwater head and contaminant transport is necessary for sustainable management of the groundwater resources. However, the groundwater simulation models are subjected to uncertainty in their predictions. The goals of this research are to: (1) quantify the uncertainty in the groundwater model predictions and (2) investigate the impact of the quantified uncertainty on the aquifer remediation designs. To pursue the first goal, this study generalizes the Bayesian model averaging (BMA) method and introduces the hierarchical Bayesian model averaging (HBMA) method that segregates and prioritizes sources of uncertainty in …

Characterization And Uncertainty Analysis Of Siliciclastic Aquifer-Fault System, Ahmed Saad Elshall

LSU Doctoral Dissertations

The complex siliciclastic aquifer system underneath the Baton Rouge area, Louisiana, USA, is fluvial in origin. The east-west trending Baton Rouge fault and Denham Springs-Scotlandville fault cut across East Baton Rouge Parish and play an important role in groundwater flow and aquifer salinization. To better understand the salinization underneath Baton Rouge, it is imperative to study the hydrofacies architecture and the groundwater flow field of the Baton Rogue aquifer-fault system. This is done through developing multiple detailed hydrofacies architecture models and multiple groundwater flow models of the aquifer-fault system, representing various uncertain model propositions. The hydrofacies architecture models focus on …

Bioremediation Of Chlorinated Ethanes And Ethenes In Vertical Flow Engineered Wetland Systems, Christopher Akudo

LSU Doctoral Dissertations

Sustainable treatment of chlorinated ethanes and ethenes contaminated groundwater using vertical flow engineered wetland systems were investigated in microcosm and column studies. Experiments on environmental and biogeochemical factors that affect system performance were conducted, and a numerical model involving advection, sorption, and sequential biodegradation was developed to describe the fate and transport of the contaminants of concern in the treatment wetland bed. 1,1-dichloroethane (1,1-DCA) and cis-1,2-dichloroethene (cis-1,2-DCE) were used as the chemicals of interest. The presence of cis-1,2-DCE inhibited dechlorination of 1,1-DCA but cis-1,2-DCE dechlorination was not affected by the presence of 1,1-DCA. Simulation runs showed that the treatment bed …

Bacterial Characterization Of Louisiana Groundwater Contaminated By Dnapl-Containing Chloroethanes And Other Solvents, Kimberly Bowman

LSU Doctoral Dissertations

In support of an effort to determine the feasibility of using an in-situ bioremediation strategy for cleanup of groundwater in an area containing chlorinated solvents present as a dense non-aqueous phase liquid (DNAPL), the bacterial population in the groundwater at a Superfund site located near Baton Rouge, Louisiana was characterized. More than 3¡Á107 cells/mL in the groundwater were observed via microscopy. Universal bacterial and ¡°Dehalococcoides¡±-specific 16S rRNA gene libraries were constructed and analyzed. Universal clones grouped into 18 operational taxonomic units (OTUs), as defined by sequence similarity ¡Ý97.0%, which included several as yet undescribed organisms. Multiple unique sequences closely related …

Saltwater Intrusion Simulation In Heterogeneous Aquifer Using Lattice Boltzmann Method, Borja Servan Camas

LSU Master's Theses

This study develops a saltwater intrusion simulation model using a lattice Boltzmann method (LBM) in a two-dimensional coastal confined aquifer. The saltwater intrusion is described by density-dependent groundwater flow and mass transport equations, where a freshwater-saltwater mixing zone is considered. The problem is formulated in terms of hydraulic head instead of pressure, which is recommended in those cases where static pressures dominate to reduce computational cost. The aquifer heterogeneity is explicitly a function of the speed of sound, relaxation parameter and time steps in the LBM. This study explores the equivalent squared sound speed to deal with the spatial-temporal heterogeneity …

Improvements In Groundwater Flow Modeling Through The Integration Of Resistivity Logs And Hydraulic Conductivity And The Use Of Variogram Uncertainty, Asheka Rahman

LSU Doctoral Dissertations

This study developed a coregionalized model to estimate hydraulic conductivity using spatial cross correlation between hydraulic conductivity and borehole geophysical data (a transform of the formation factor). An experimental pseudocross variogram is used instead of a cross variogram because data are not collocated. Experimental variogram uncertainty is investigated using confidence intervals for the experimental variogram calculated assuming variogram sills are lognormally distributed. These intervals are used for sensitivity modeling using kriging, cokriging, simulation and cosimulation. The hydraulic conductivity fields generated by kriging, cokriging, simulation, and cosimulation are then used in a high-resolution groundwater model created using telescopic mesh refinement (TMR) …