Spelling suggestions: "subject:"nonaqueous phase liquid."" "subject:"monaqueous phase liquid.""
1 |
Enhanced dissolution of multiple-component nonaqueous phase organic liquids in porous media using Cyclodextrin theoretical, laboratory, and field investigations /McCray, John Emory. January 1998 (has links) (PDF)
Thesis (Ph. D - Hydrology and Water Resources) / Includes bibliographical references (leaves 208-221).
|
2 |
Immunotoxic and immunodisruptive effects of selected dense non-aqueous phase liquids in immunocompromised cells31 March 2009 (has links)
M.Sc. / Dense non-aqueous phase liquids (DNAPLs) are groups of chemicals often found beneath the water surface when chemical contamination of water occurs and they are called groundwater contaminants. Their improper storage and extensive use in industries as well as their slow degradation provide a long term source for of low level contamination of ground- and river water. Evidence from both human and animal studies suggests that volatile organic and organochlorinated compounds (specific types of DNAPLs), may increase host susceptibility to microbial infection, induce alterations in the maturation of effector immune cells and compromise immune surveillance mechanisms. These effects of DNAPLs hold special relevance for people living with HIV/AIDS. In light of this, the present study investigated the in vitro immunological effects of the two most common DNAPLs contaminants, Trichloroethylene (TCE) and Aroclor-1254 (ARO) in peripheral blood mononuclear cells (PBMCs) of immunocompromised and healthy donors. TCE and ARO were successfully dissolved in cell culture medium and added to freshly isolated PBMCs in a 1:1 ratio. Following incubation, cell functionality and cytotoxicity (or immunotoxicity) were assessed using MTT and LDH. Viability was confirmed and/or cell death analyzed by flow cytometry. Culture supernatants were used to assess NO and cytokine production as well as for quantification of viral replication. TCE and ARO induced a significant (p<0.05) decrease in cell viability/functionality in a dose-dependent manner. Flow cytometric analysis of cell death pathways indicated that TCE and ARO induced apoptosis. These chemicals also induced the secretion of both NO and proinflammatory cytokines suggesting that they may induce apoptosis via an inflammatory pathway, which may explain the mitochondrial dysfunction as determined by the MTT assay. ARO effects were more prominent than those of TCE, and both were more detrimental to HIV positive PBMCs compared to uninfected cells. The viral p24 levels increased in a dose-dependent fashion suggesting an effect for TCE and ARO on viral replication. This research concludes that DNAPL-contamination is detrimental to especially immuno-compromised systems.
|
3 |
Evaluation of microbial reductive dechlorination in tetrachloroethene (PCE) Dense Nonaqueous Phase Liquid (DNAPL) source zonesAmos, Benjamin Keith January 2007 (has links)
Thesis (Ph.D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Löffler, Frank E.; Committee Member: Hughes, Joseph B.; Committee Member: Pennell, Kurt D.; Committee Member: Spain, Jim C.; Committee Member: Taillefert, Martial
|
4 |
Value and reliability of DNAPL investigation programs /McGrath, Travis Christopher, January 1998 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 469-477). Available also in a digital version from Dissertation Abstracts.
|
5 |
Enhanced dissolution of multiple-component nonaqueous phase organic liquids in porous media using Cyclodextrin : theoretical, laboratory, and field investigationsMcCray, John Emory. January 1998 (has links)
The effectiveness of a cyclodextrin (sugar-based) solution for enhancedsolubilization removal of multicomponent nonaqueous phase organic liquid (NAPL) contamination from an aquifer is tested in a pilot-scale field experiment. This effort is the first field test of this innovative technology, termed a "Complexing Sugar Flush" (CSF). The saturated zone within an enclosed cell was flushed with 8 pore volumes of 10wt% cyclodextrin solution. The cyclodextrin solution increased the aqueous concentrations of all the target contaminants to values from about 100 to more than 20,000 times the concentrations obtained during a water flush conducted immediately prior to the CSF. The degree of solubility enhancement was greater for the morehydrophobic contaminants. Conversely, the relative mass removal was greater for the less-hydrophobic compounds due to their generally higher apparent solubilities. The average reduction in NAPL mass for the target contaminants was about 41%. A relationship is developed to describe enhanced dissolution of a multiple-component NAPL, and is used to analyze the field data. The effluent concentrations for most of the target contaminants during the cyclodextrin flush were within a factor of two of the equilibrium values predicted using this theory. Deviations from ideal dissolution behavior were also observed. Finally, the cyclodextrin solution appeared to significantly enhance both the magnitude and the rate of NAPL dissolution compared to a water flush conducted prior to the cyclodextrin flush. These results contribute to a better understanding of the important physicochemical processes involved in using enhancedsolubilization agents for the remediation of multiple-component NAPLs.
|
6 |
Development and demonstration of a biodegradation model for non-aqueous phase liguids in groundwater /De Blanc, Phillip Charles, January 1998 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 342-347). Available also in a digital version from Dissertation Abstracts.
|
7 |
DNAPL migration in single fractures : issues of scale, aperture variability and matrix diffusion /Hill, Katherine I. January 2007 (has links)
Thesis (Ph.D.)--University of Western Australia, 2007.
|
8 |
Development and evaluation of partitioning interwell tracer test technology for detection of non-aqueous phase liquids in fractured media /Deeds, Neil Edward, January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 362-371). Available also in a digital version from Dissertation Abstracts.
|
9 |
Dynamics of residual non-aqueous phase liquids in porous media subject to freeze-thawSingh, Kamaljit, Engineering & Information Technology, Australian Defence Force Academy, UNSW January 2009 (has links)
This project concerns the effect of 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 literature to date. This research work is conducted in three stages: (i) two-dimensional nondestructive visualisation of residual light non-aqueous phase liquid (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 explanation of results by several pore scale mathematical and conceptual models. The two-dimensional cell experiments (using a monolayer of 0.5 mm diameter glass beads held between two glass sheets), and three-dimensional X-ray micro-CT experiments reveal a substantial mobilisation and rupture of ganglia during successive freeze-thaw cycles; this includes the detachment of smaller ganglia from larger ganglia and the mobilisation of NAPL in the direction of freezing front. The experiments also reveal significant shedding of numerous single/sub-singlet ganglia along narrow pore corridors, their entrapment in growing polycrystalline ice, and the coalescence of such small ganglia during thawing to form larger singlets. These changes were more predominant where the freezing commenced. The results of the experimental studies were interpreted by developing several mathematical and conceptual models, including freezing-induced pressure model, Darcy's law model, multipore ganglia model (rupture coefficient) and ice-snap off model.
|
10 |
Radon-222 as an in situ partitioning tracer for quantifying nonaqueous phase liquid (NAPL) saturations in the subsurfaceDavis, Brian M. 30 January 2003 (has links)
This study investigated the use of radon-222 as an in situ partitioning tracer for
quantifying nonaqueous phase liquid (NAPL) saturations in the subsurface.
Laboratory physical aquifer models (PAMs), field experiments, and numerical
simulations were used to investigate radon partitioning in static (no-flow) experiments
and in single-well, 'push-pull' tests conducted in non-contaminated and NAPL-contaminated
aquifers. Laboratory push-pull tests in a wedge-shaped PAM and field
push-pull tests in a NAPL-contaminated aquifer showed that radon was retarded in the
presence of NAPL, with retardation manifested in increased dispersion of radon
extraction phase breakthrough curves (BTCs). An approximate analytical solution to
the governing transport equation and numerical simulations provided estimates of the
radon retardation factor (R), which was used to calculate NAPL saturations (S[subscripts n]).
Laboratory static and push-pull tests were conducted in a large-scale
rectangular PAM before and after NAPL contamination, and after alcohol cosolvent
flushing and pump-and-treat remediation. Radon concentrations in static tests were
decreased due to partitioning after NAPL contamination and increased after
remediation. Push-pull tests showed increased radon retardation after NAPL
contamination; radon retardation generally decreased after remediation. Numerical
simulations modeling radon as an injected or ex situ partitioning tracer were used to
estimate retardation factors and resulted in overestimations of the likely S[subscripts n] in the
PAM. Radon partitioning was sensitive to changes in S[subscripts n] in both static and push-pull
tests. However, the test results were sensitive to test location, sample size, test design,
and heterogeneity in S[subscripts n] distribution.
Numerical simulations of hypothetical push-pull tests conducted in a NAPL-contaminated
aquifer were used to investigate the influence of homogeneous and
heterogeneous S[subscripts n] distributions and initial radon concentrations on radon BTCs and
resulting S[subscripts n] calculations. Both of these factors were found to affect radon BTC
behavior. A revised method of plotting and interpreting radon BTCs combined with
numerical simulations modeling radon as an in situ partitioning tracer (incorporating
initial radon concentrations into the model as a function of S[subscripts n]) were used to re-analyze
laboratory and field push-pull test BTCs. This method reduced the overestimation of
calculated S[subscripts n] values from laboratory tests. / Graduation date: 2003
|
Page generated in 0.0446 seconds