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vadosezone, etc ; dispersibility; energy; groundwater; soil; Show all 5 Subjects
Abstract:
... Release of colloids and their subsequent transport into the subsurface environments takes place during a wide range of applications such as industrial, energy storage, and agricultural activities. Therefore, processes contributing to transport, attachment, and re-mobilization of colloids in porous media are attracting attention. A fraction of the released colloids may cross the soil vadose zone to ...
vadosezone, etc ; air; aquifers; groundwater; remediation; soil; water table; Show all 7 Subjects
Abstract:
... The present study proposes a methodology for predicting the vertical light nonaqueous‐phase liquids (LNAPLs) distribution within an aquifer by considering the influence of water table fluctuations. The LNAPL distribution is predicted by combining (1) information on air/LNAPL and LNAPL/water interface elevations with (2) the initial elevation of the water table without LNAPL effect. Data used in th ...
vadosezone, etc ; Bayesian theory; electrical conductivity; geostatistics; permeability; soil heterogeneity; water; Show all 7 Subjects
Abstract:
... Non-invasive geo-electrical tools are widely used to monitor vadose zone processes. At the core of these methods is the assumption that the obtained subsurface’s electrical conductivity maps can be translated to hydrological state-variables via site-specific hydro-electrical relations calibrated with laboratory or field data. However, the common practice that assumes spatially homogeneous hydro-el ...
vadosezone, etc ; aquifers; ecosystems; groundwater; hydraulic resistance; hydrochemistry; land use; models; risk assessment; topography; Show all 10 Subjects
Abstract:
... Accurate and effective assessment of groundwater vulnerability is very important for ensuring a healthy groundwater ecosystem. We evaluate the vulnerability of shallow porous aquifers by modifying the DRASTIC model and verify the effectiveness of the variable weight model (VWM). Firstly, topography, aquifer media, and the impact of the vadose zone are replaced by land-use type, aquifer thickness, ...
... The increase in the frequency of extreme precipitation events due to climate change, together with the continuous development of cities and surface sealing that hinder water infiltration into the subsoil, is accelerating the search for new facilities to manage stormwater. The Canary Islands (Spain) are taking advantage of the knowledge acquired in the construction of water mines to exploit a novel ...
vadosezone, etc ; Actinobacteria; Firmicutes; Proteobacteria; alkanes; aquifers; bacterial communities; biodegradation; diesel fuel; genes; water content; water table; Show all 12 Subjects
Abstract:
... n-Alkanes, the main component of diesel fuel, are common light non-aqueous phase liquids (LNAPLs) that threaten ecological security. The subsurface from vadose zone, through fluctuating zone, to saturated zone, is a critical multi-interface earth layer which significantly affects the biodegradation processes of n-alkanes. A pilot-scale diesel contaminated aquifer column experiment has been underta ...
... Predicting the outcome of a natural process is extremely difficult and challenging. Processes in the vadose zone are complex and transport of contaminants to the aquifers has been the subject of many previous research and models. It is possible to estimate water and pollutant transport in the unsaturated zone with many models, from simple to complex, developed over the previous few decades. More a ...
vadosezone, etc ; adsorption; groundwater; miscible displacement; Show all 4 Subjects
Abstract:
... A growing body of site investigations have demonstrated that vadose zones serve as significant long-term sources of PFAS to groundwater. Quantifying PFAS leaching in the vadose zone and mass discharge to groundwater is therefore critical for characterizing, managing, and mitigating long-term contamination risks. Mathematical models representing the PFAS-specific transport and retention processes, ...
... Horizontal borehole ground penetrating radar (GPR) measurements can provide valuable information on soil water content (SWC) dynamics in the vadose zone, and hence show potential to estimate soil hydraulic properties. In this study, the performance of both sequential and coupled inversion workflows to obtain soil hydraulic properties from time-lapse horizontal borehole GPR data obtained during an ...
vadosezone, etc ; data collection; electrical resistance; temperature; tomography; Show all 5 Subjects
Abstract:
... Time‐lapse electrical resistivity tomography (ERT) can be used to image a wide variety of subsurface processes. It is often necessary to remove the effects of seasonal near‐surface temperature variability in order to interpret the signal of interest. Here, we use a synthetic modeling approach to explore the challenges related to removing temperature effects from ERT data in seasonally frozen groun ...
vadosezone, etc ; adsorption; groundwater; lysimeters; molecular weight; risk; soil; Show all 7 Subjects
Abstract:
... Determining the risk posed by PFAS leaching from soil to groundwater requires quantification of the magnitude and temporal/spatial variability of PFAS mass discharge from the vadose zone, which is governed in part by the concentrations of PFAS in soil porewater. Porewater concentrations are impacted and mediated by the properties of the PFAS and soil, multiple transport and fate processes, and sit ...
vadosezone, etc ; biodegradation; groundwater; microbial communities; volatilization; water content; Show all 6 Subjects
Abstract:
... The natural attenuation potential of a vadose zone against diesel is critical for optimizing remedial actions and determining groundwater vulnerability to contamination. Here, diesel attenuation in unsaturated soils was systematically examined to develop a qualitative relationship between physical soil properties and the natural attenuation capacity of a vadose zone against diesel. The uniformity ...
vadosezone, etc ; adsorption; environment; environmental fate; models; surface tension; Show all 6 Subjects
Abstract:
... Salts are known to have strong impacts on environmental behavior of per- and polyfluoroalkyl substances (PFAS) including air-water interfacial adsorption. Multivalent salts impact interfacial adsorption to a greater extent than monovalent salts. Models to make a priori predictions of PFAS interfacial adsorption in the presence of multiple salts with different ionic charges are needed given the nee ...
vadosezone, etc ; groundwater; groundwater recharge; hydrograph; irrigation; water table; China; Show all 7 Subjects
Abstract:
... Jingdian Irrigation District, Northwest China. In arid regions, there is a significant lag in groundwater recharge due to the large thickness of vadose zone. For areas with insufficient hydrogeological data, it is quite difficult to calculate the delayed recharge of groundwater. An improved transfer function (ITF) is established based on the instantaneous unit hydrograph of the vadose zone for are ...
vadosezone, etc ; capillary fringe; freshwater; seawater; unsaturated flow; water table; Show all 6 Subjects
Abstract:
... This study develops approximate analytical solutions for seawater extent in unconfined coastal aquifers considering unsaturated flow, and assuming steady-state, sharp-interface conditions, for both constant flux (flux-controlled aquifers) and constant head (head-controlled aquifers) inland boundary conditions. These analytical solutions were verified with numerical simulations of variable-saturati ...
vadosezone, etc ; adsorption; models; preferential flow; uncertainty; water; water content; Show all 7 Subjects
Abstract:
... PFAS are emergent contaminants of which the fate and transport in the environment remain poorly understood. As surfactants, adsorption at air–water and solid–water interfaces in soils complicates the retention and leaching of PFAS in the vadose zone. Recent modeling studies accounting for the PFAS-specific nonlinear adsorption processes predicted that the majority of long-chain PFAS remain in the ...
vadosezone, etc ; basins; computer software; groundwater; groundwater contamination; hydraulic conductivity; issues and policy; models; risk assessment; statistical analysis; topography; unconfined aquifer; water table; watersheds; India; Show all 15 Subjects
Abstract:
... In the recent years, ground water vulnerability or more specifically contamination of unconfined aquifer has been intensified due to multiple reasons. A GIS-based DRASTIC model was used for assessment of groundwater vulnerability on upper Dwarakeshwar river basin, India. Seven intrinsic hydro-geological parameters like depth of water table, net recharge, aquifer media, soil media, topography, the ...
vadosezone, etc ; geochemistry; ionic strength; lard; models; nitrates; pH; plutonium; sorption; Show all 9 Subjects
Abstract:
... Beginning in 1943, process wastes containing approximately 1.85 × 10¹⁵ Bq (200 kg) of plutonium (Pu) were released into unlined cribs, trenches, and field tiles at the Hanford Site, Washington, USA. The 216-Z-9 (Z-9) unlined trench received over 4 × 10⁶ L of mixed Pu processing waste from the Plutonium Finishing Plant (PFP) consisting of high ionic strength (∼ 5 M nitrate, ∼ 0.6 M aluminum), acidi ...
vadosezone, etc ; environmental engineering; fractal dimensions; models; permeability; porosity; water flow; Show all 7 Subjects
Abstract:
... Predicting the permeability of porous media in saturated and partially saturated conditions is of crucial importance in many geo-engineering areas, from water resources to vadose zone hydrology or contaminant transport predictions. Many models have been proposed in the literature to estimate the permeability from properties of the porous media such as porosity, grain size or pore size. This study ...
vadosezone, etc ; geophysics; models; porous media; research; water content; water table; Show all 7 Subjects
Abstract:
... Improving our understanding of the relation between the water content and the seismic signatures of unconsolidated superficial soils is an important objective in the overall field of hydrogeophysics. Current approaches to constrain the water content in the vadose zone from seismic data are based on computing the ratio between compressional and shear wave velocities Vₚ/Vₛ. While this allows for the ...