Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 21 for “"Non-Aqueous Phase Liquids"”.
-
Surfactant enhanced mobilisation of non-aqueous phase liquids
The remediation of non-aqueous phase liquid (NAPL) using conventional aquifer treatment technologies is limited by the low solubility of NAPLs. Surfactants can promote the enhanced removal of NAPL through mobilisation, a mechanism that relies on the reduction of interfacial tension (IFT) at the …
-
Dynamics of residual non-aqueous phase liquids in porous media subject to freeze-thaw
… cycles on the pore-scale structure of nonaqueous phase liquid (NAPL) contaminants in water-saturated porous media. This problem is of critical importance to the entrapment of such contaminants in cold temperate, polar and high altitude regions, and has not been examined in the …
-
Mass transfer from non-aqueous phase liquids to the aqueous phase in groundwater systems
… subsurface environment, a significant portion of non-aqueous phase liquids (NAPL's) is trapped by capillary forces and remains in the subsurface as immobile blobs or ganglia. Residual saturations of NAPL on the order of 5-30 percent have been observed in saturated subsurface systems. The NAPL can …
-
Surfactant enhanced solubilization of dense non-aqueous phase liquids (DNAPLs) for application to in-situ porous media remediation
Includes bibliographical references.
-
Hydrogeologic Model of a Leachate Plume in an Unconfined Coastal Plain Aquifer and Chemical Transport Mechanisms of Metals and Dense Non-Aqueous Phase Liquids
<p>Groundwater contamination is of increasing environmental concern as many aquifers across the globe have experienced a decrease in water quality in recent time. The growth of the world's population over the last couple of decades has caused a dramatic increase in the rate of groundwater use. One …
-
Cross borehole induced polarization to detect subsurface NAPL at the Savannah River Site, South Carolina
… was performed to delineate the presence of dense non-aqueous phase liquids (DNAPL) which were periodically released from the 1950's through the 1980's at the A-14. Measurements were made at 1/4 and 1/16 Hertz and the first four odd harmonics. Data inversion for model parameters was performed with …
-
Experimental and theoretical modeling of DNAPL transport in vertical fractured media
… years, groundwater contamination by dense, non-aqueous phase liquids (DNAPLs) such as chlorinated solvents and polychlorinated biphenyls (PCBs) has become an important environmental concern in many industrialized areas. Accidental spills, poor storage facilities and inadequate disposal …
-
The use of Geographic Information System (GIS) for regional scale groundwater contamination risk assessment by chlorinated solvents in the Permo-Triassic sandstone aquifer
… contamination of groundwater resources by dense non-aqueous phase liquids (DNAPLs) such as chlorinated solvents is an increasing problem being faced throughout the industrialised world. The transport and eventual fate of these compounds in the subsurface is controlled by the nature of the …
-
NAPL remediation by vacuum-enhanced recovery: Laboratory and model evaluations
… of Vacuum Enhanced Recovery (VER) to remediate non aqueous phase liquids (NAPLs) in the vadose zone. The first paper demonstrates the use of a pilot-scale two-dimensional laboratory soil cell and an automated dual-energy gamma ray attenuation system for the feasibility assessment of VER to …
-
A Self-Potential for Monitoring Self-Sustaining Treatment for Active Remediation (STAR)
… (STAR) is a novel soil remediation approach for Non-Aqueous Phase liquids (NAPLs) embedded in a porous medium. STAR is based on liquid smoldering combustion which destroys NAPLs while simultaneously generating heat due to the exothermic oxidation reaction. The technique is currently in use in …
-
Development of hydrogel tracer beads and comparative tracer tests to better understand contaminant fate and transport in karst systems
… of immiscible organic compounds in the form of non-aqueous phase liquids (NAPLs). The fate and transport of NAPLs in karst aquifers is poorly understood. Tracer tests allow for qualitative characterization of hydraulic flow in the surface and subsurface, but their results may not be applicable …
-
Modeling biotic and abiotic decay of trichloroethylene (TCE) using the Reactive Multi-Species Transport in 3-Dimensional Groundwater Aquifers (RT3D) code
Removal of dense non aqueous phase liquids, DNAPLS, such as trichloroethylene, TCE, is vital to improving the health of groundwater systems. TCE contamination of groundwater systems is of significant concern and its removal a significant challenge. One of the main causes of delays in cleanup of a …
-
NAPL (Non Aqueous Phase Liquid) source characterization based on dissolved contaminant concentrations
… originates from spatially distributed sources of Non-Aqueous Phase Liquids (NAPLs). Such chemicals are typically persistent sources of groundwater contamination that are difficult to characterize. This work addresses the feasibility of using dissolved concentration measurements to estimate the …
-
Modeling the Dissolution of Immiscible Contaminants in Groundwater for Decision Support
… These include unknown residual amounts of non-aqueous phase liquids (NAPL) and source zone dimensions, inconsistent historical monitoring of contaminant mass discharge, and the mathematical simulation of field-scale mass transfer processes. Effective methods for simulating NAPL dissolution …
-
Using 3D Tomography to Understand Fluid-Fluid Interface Evolution in Porous Media for Carbon Sequestration Applications
Fundamental understanding of multi-phase flow in porous media is needed to deploy subsurface engineering processes such as geologic carbon sequestration (GCS) that works by injecting and storing carbon dioxide (CO2) into underground geologic formations. In this PhD project, the in-situ fluid …
-
Using 3D Tomography to Understand Fluid-Fluid Interface Evolution in Porous Media for Carbon Sequestration Applications
Fundamental understanding of multi-phase flow in porous media is needed to deploy subsurface engineering processes such as geologic carbon sequestration (GCS) that works by injecting and storing carbon dioxide (CO2) into underground geologic formations. In this PhD project, the in-situ fluid …
-
Particle Detachment in Single-Phase and Two-Phase Flows in Porous Media
… to account for the presence of a residual phase. Compared with fines migration under single-phase flow, having a residual phase significantly reduces the permeability variation. Analytical solutions for over and undersaturated state of fines were also derived in this thesis. Oversaturation …
-
Solubilization of volatile organic compounds in edible nonionic surfactants
… are major subsurface contaminants and exist as Non-Aqueous Phase Liquids (NAPLs) in the subsurface. Pump-and-treat remediation is the most common technology used to remediate contaminated groundwater. However, experience has revealed that the traditional pump-and-treat remediation is impractical …
-
Quantification of Parameters in Models for Contaminant Dissolution and Desorption in Groundwater
… a simulated contaminant source zone and the aqueous phase. Where direct observation has fallen short, this study attempts to interpret field data using an inverse modeling technique for the purpose of constraining mass transfer processes which are poorly understood at the field scale. Inverse …
-
Processes controlling the behavior of LNAPLs at groundwater surface water interfaces
Releases of Light Non-Aqueous Phase Liquids (LNAPLs) are a significant problem at many sites. This thesis explored governing processes pertaining to LNAPL releases at groundwater surface water interfaces (GSIs). Governing processes were investigated via laboratory studies and a preliminary analysis …
Page 1 of 2