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Showing 1 to 20 of 21 for “"DNAPL"”.
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Experimental and theoretical modeling of DNAPL transport in vertical fractured media
… 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 practices are factors …
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Characterization of subsurface DNAPL movement with ground penetrating radar and inverse multiphase flow simulations
Includes bibliographical references (pages 140-145).
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Investigation into dense non-aqueous phase liquid (DNAPL) transport and remediation in vertical fractures
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000.
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Stochastic analysis of dense nonaqueous phase liquid dissolution in naturally heterogeneous subsurface systems
Field-scale Dense Nonaqueous Phase Liquid (DNAPL) dissolution in three-dimensional heterogeneous subsurface systems is investigated using a stochastic approach that treats the variability of flow properties as three-dimensional random fields. A steady-state, quasi-static DNAPL saturation …
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Numerical Modeling of Steam Flushing for Removal of Dense Nonaqueous Phase Liquids
… for removal of dense nonaqueous phase liquids (DNAPL), including perchloroethylene (PCE), a mixture of PCE and nonane, and a mixture of monochlorobenzene (MCB) and dichlorodiphenyltrichloroethane (DDT) perched on a barrier layer were simulated with a nonisothermal multiphase, multicomponent …
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Prediction of mass flux from DNAPL source zone with complex entrapment architecture: model development, experimental validation, and up-scaling
Includes bibliographical references (pages 219-229).
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Influence of Soil Moisture Dynamics on DNAPL Spill Zone Architecture and Its Impact on Mass Removal Mechanisms During Soil Vapor Extraction in Heterogeneous Porous Media
The spatial distribution of DNAPL saturation, water saturation, and soil permeability (i.e., spill zone architecture) determines the pore-scale processes that control soil vapor extraction (SVE). To test this hypothesis, a fully coupled multiphase flow and transport simulator, STOMP was chosen. …
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Cross borehole induced polarization to detect subsurface NAPL at the Savannah River Site, South Carolina
… 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 the use of proprietary …
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Redutive Dehalogenation of Chlorinated Alkanes by Novel Bacteria at the PetroProcessor of Louisiana Inc. Superfund Site
… within the dense non-aqueous phase liquid (DNAPL) source zone at the PPI site. Results revealed the presence of bacteria similar or identical to strains BL-DC-8 and BL-DC-9 as well as “Dehalococcoides” strains throughout the DNAPL source zone. 16S rRNA gene copy concentrations as high as …
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The use of Geographic Information System (GIS) for regional scale groundwater contamination risk assessment by chlorinated solvents in the Permo-Triassic sandstone aquifer
… 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 chemical spillage, the …
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Dynamics of residual non-aqueous phase liquids in porous media subject to freeze-thaw
… (LNAPL), and dense non-aqueous phase liquid (DNAPL), in porous media subject to successive freeze-thaw cycles; (ii) three-dimensional experiments on LNAPL in porous media subject to freeze-thaw, with quantification of phase volumes by X-ray micro-computed tomography (micro-CT); and (iii) the …
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Stability, transport and applications of polyaphrons in porous media
… the density of dense non-aqueous phase liquid (DNAPL) contaminants in situ. We first investigate how the stability of diluted polyaphrons is affected by the properties of the continuous phase. We find that polyaphrons can be destabilized by a low concentration of Al3+ or Ca2+ in the continuous …
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Effective properties of multiphase flow in heterogeneous porous media
… width of a dense nonaqueous phase liquid (DNAPL) plume or air sparging contributing area is derived to evaluate the sensitivity of system behavior to properties of input processes. Anisotropy is predicted for uniform, vertical flow in the Borden Aquifer consistent with both prior …
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Reaction Rates For The Dehalogenation Of Trichloroethylene Using Various Types Of Zero-valent Iron
… remediation of dense, nonaqueous-phase liquids (DNAPLs). Permeable reactive barrier walls (PRBW) have been installed at many sites around the country to treat contaminated plumes resulting from the presence of DNAPL pools. The use of zero-valent metals, such as iron, to effectively reductively …
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Characterization of a Creosote-Contaminated Tie Yard Site and the Effects of Phytoremediation
… creosote sources. Areal subsurface bedrock DNAPL distribution, approximately 6500 ft², was much greater than previously reported. Total PAHs (Σ 6 PAHs) in the soil and ground water ranged from below detection limits (BDL) to 8,276 mg/kg and BDL to 1.58 mg/L, respectively. Aqueous phase PAHs …
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Solubilization of volatile organic compounds in edible nonionic surfactants
… in the subsurface, especially for dense NAPLs (DNAPLs). The difficult desorption of highly hydrophobic compounds and the inability to dissolve residual saturation are the major limiting factors for traditional pump-and-treat remediation. Different chemicals have been used to enhance traditional …
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Direct Volatilization of Naphthalene at a Creosote-Contaminated Site with a Phytoremediation System
… PAHs have decreased over the years as the DNAPL contamination has become more enriched with the larger PAHs. This thesis focuses on the movement of naphthalene through the subsurface because it comprises the majority of the creosote and evidence for its remediation exists. Of the many …
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