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.
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Showing 1 to 20 of 26 for “"Saturated zone"”.
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The distribution of vertical groundwater flow in the saturated zone of the Yucca Mountain area: A cross-sectional finite element model
… uses cross-sectional modeling to explore the saturated groundwater flow at Yucca Mountain in a multi-layer system. Cross-sectional modeling allows the simulation of vertical leakage not included in areal models. The cross section was constructed along an estimated streamline and is 84.3 …
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Optimizing Phytoremediation to Enhance Treatment Efficiency of Suspended Raingardens
… pollutant-removal efficiency of columns with a saturated zone (SZ) or non-saturated zone (NSZ) was tested for five different lightweight media bases: perlite, vermiculite, activated carbon, zeolite, and coconut coir. All columns were added with compost as a source of organic matter. Every column …
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Denitrification in the Elk Valley aquifer, northeastern North Dakota
… groundwater flow and nitrate distribution in the saturated zone. </p><p> The aquifer is unconfined and consists of up to 20 metres of glacial outwash and deltaic shale-rich sand deposits. The water table ranges from two to five metres below the surface. Groundwater flows to the southeast at an …
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The Hydrogeologic effects of fly ash utilization in concrete at Coal Creek Station, Underwood, North Dakota
… monitoring network encompassing surface water, unsaturated zone water, and saturated zone water was designed for the site. Surface water quality was documented using a runoff collector and precipitation collector. soil moisture and ground water occurrence and quality were monitored using …
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The effect of oil-and-gas well drilling fluids on shallow groundwater in western North Dakota
… of the study sites, Water obtained from the unsaturated zone beneath the buried drilling fluid at all of the four study sites exceeds some of the Recommended and Maximum Permissible Concentration Limits for trace elements and major ions (As, Cl-, Pb, Se and N03-). These values are greatly …
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In situ characterization and quantification of phytoremediation removal mechanisms for naphthalene at a creosote-contaminated site
… at this site are biodegradation in the saturated zone, volatilization and biodegradation in the vadose zone and phytovolatilization. This is probably the most comprehensive field study of PAH phytoremediation mechanisms conducted to date. The significance of this research is to …
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Formulation and testing of a distributed triangular irregular network rainfall/runoff model
… RIBS model is used to provide runoff and saturated/unsaturated groundwater dynamics in the system. These two base models of tRIBS are described and the modifications to CHILD and RIBS are presented. The CHILD model is modified to accept time varying distributed inputs and a saturated zone …
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Analysis of Aquifer and Operational Conditions for Successful Soil Aquifer Treatment of Treated Wastewater via Synthesis of Published Full-Scale and Laboratory-Scale Studies
… Moreover, extended residence times in the saturated zone provide little additional bulk organic and nitrogen removal for aquifers with vadose zones that achieve more than 85% of total bulk organic removal. The results of this study should enhance feasibility studies for future soil aquifer …
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Direct Transpiration and Naphthalene Uptake Rates for a Hybrid Poplar Based Phytoremediation System
… to determine direct transpiration rates from the saturated zone of the shallow, unconfined aquifer underlying the site. Direct transpiration rates varied over the growing season (late March to mid-October), with a maximum and mean daily direct transpiration of 0.0100 and 0.0048 feet/day, …
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A subsurface water quality evaluation system for assessing NPS pollution potential by pesticides
… by dividing the subsurface domain into root zone, intermediate vadose zone, and saturated zone, respectively. On each of the homogeneous subfields, the physically-based models, PRZM and VADOFT, were linked to simulate pesticide transport in the root and intermediated vadose zones. Pesticide …
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Evaluation of Propane-Butane Mixtures as Solvent in ES-SAGD
… the oil gets filled with steam, forming a steam saturated zone called a steam chamber. With continued steam injection and oil production, the steam chamber expands vertically and laterally. The SAGD process involves high capital and operating costs, and it suffers from environmental issues. One …
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Biodegradation of methanol and tertiary butyl alcohol in previously uncontaminated subsurface systems
… mg/L/day and rates were generally greater in the saturated zone. TBA biodegraded at all sites, but was refractory in nature. Biodegradation rates for TBA in anaerobic subsurface systems were found to increase directly with initial concentration from 10⁻⁴ mg/L/day for 1 mg/L to 10⁻¹ mg/L/day for 80 …
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Hydrological and erosion responses to man-made and natural disturbances : insights from forested catchments in South-central Chile
… logging, 4) possible hydrologic responses of the saturated zone to the 2010 Maule earthquake and 5) responses of the vadose zone to this earthquake. Re 1) In order to quantify the hydrologic impact of plantation forests, it is fundamental to first establish their water balances. I show that tree …
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Stormwater treatment during infiltration and its effect on shallow urban groundwater quality in the Cape Flats Aquifer: field study and soil-column experiments
… driven by denitrification and improved in the saturated zone. Denitrification during infiltration was improved by the addition of organic carbon to the synthetic stormwater, however this also resulted in slightly higher concentrations of geogenic contaminants arsenic (13.6 vs 6.9 μg/L), iron …
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Spatial arrangement of stormwater infiltration affects partitioning of subsurface storage and baseflow timing
… subsurface partitioning of water between unsaturated and saturated zones, and baseflow response duration and timing. Our findings show that more spatially distributed infiltration facilities, as compared to spatially-clustered infiltration facilities, encourage greater unsaturated zone …
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A continuous real-time interactive basin simulator (RIBS)
… the description of infiltration and subsurface saturated lateral exchange processes. The infiltration model is revised to include a modified Green-Ampt scheme which allows one to account for the capillary effects during infiltration in a soil that has exponential decay of the saturated …
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The Low Temperature Surface Geochemistry And Kinetics Of Pyrrhotite Weathering: Influences On Acid Mine Drainage (amd)
… oxidized pyrrhotite surfaces are compositionally zoned. The outermost surface layer is Fe(III)-oxyhydroxide, below which exists an Fe-deficient, S-rich layer that displays a continuous, gradual decrease in S/Fe until that of the unaltered pyrrhotite. Compositional zones develop by electron and …
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Characterisation of sedimentary structure and hydraulic behaviour within the unsaturated zone of the Triassic Sherwood Sandstone aquifer in North East England
… of moisture migration in the vadose zone at a single field site. Sedimentary structure and likely permeability variations were studied by use of laboratory grainsize analysis, logging of nearby outcrops, borehole geophysics and Ground Penetrating Radar (GPR). GPR is ideal for vadose …
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Hydrogeology of the Hillsboro landfill, Hillsboro, North Dakota
… in silt and sand at various intervals within the zone of saturation. Although contaminant levels appear to be low, degradation of groundwater beneath the landfill is evident. Most notably, the concentrations of the trace metals arsenic, cadmium, selenium, lead, copper, chromium, iron, and …
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Reliability Analysis of Tailings Storage Facility Embankments: Investigating the Effect of Zonation on Slope Stability
… as the subdivision of the embankment into zones of distinct hydraulic and mechanical characteristics, influences probabilistic evaluations of TSF stability. Three conceptual embankment models were developed to represent different phreatic conditions: Model A with a moderate phreatic …
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