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Journal of Contaminant Hydrology

James L Hoggan, David A Sabatini, Tohren C G Kibbey
Recent developments in nanotechnology have seen an increase in the use of manufactured nanomaterials. Although their unique physicochemical properties are desirable for many products and applications, concern continues to exist about their environmental fate and potential to cause risk to human and ecological health. The purpose of this work was to examine one aspect of nanomaterial environmental fate: transport and retention in the unsaturated zone during drainage. The work made use of tall segmented columns packed with layers of two different porous media, one medium sand and one fine sand...
October 13, 2016: Journal of Contaminant Hydrology
HaiMing Li, JinBu Wei, YaChao Ge, ZhanQuan Wang, Ye Wang, YingLong Li
This experiment was conducted with an indoor sand-column device, the migration of colloids with the presence of Na(+) and Ca(2+) and the migration of ammonia nitrogen with the presence of Na(+), Ca(2+) or/and colloids was studied. The results showed that the migration of colloids was influenced by the ion valence state, different ions with different valence could block the migration of colloids. In addition, the blocking effect of bivalent ions was more obvious than that of monovalent ions. In the presence of Na(+) and Ca(2+), the Rd value of the ammonia-nitrogen migration process were 1...
October 7, 2016: Journal of Contaminant Hydrology
Soumyadeep Mukhopadhyay, Sumona Mukherjee, Adeeb Hayyan, Maan Hayyan, Mohd Ali Hashim, Bhaskar Sen Gupta
Deep eutectic solvents (DESs) are a class of green solvents analogous to ionic liquids, but less costly and easier to prepare. The objective of this study is to remove lead (Pb) from a contaminated soil by using polyol based DESs mixed with a natural surfactant saponin for the first time. The DESs used in this study were prepared by mixing a quaternary ammonium salt choline chloride with polyols e.g. glycerol and ethylene glycol. A natural surfactant saponin obtained from soapnut fruit pericarp, was mixed with DESs to boost their efficiency...
September 20, 2016: Journal of Contaminant Hydrology
M Vasudevan, C D Johnston, T P Bastow, G Lekmine, J L Rayner, I M Nambi, G Suresh Kumar, R Ravi Krishna, G B Davis
The extent of dissolution of petroleum hydrocarbon fuels into groundwater depends greatly on fuel composition. Petroleum fuels can consist of thousands of compounds creating different interactions within the non-aqueous phase liquid (NAPL), thereby affecting the relative dissolution of the components and hence a groundwater plume's composition over long periods. Laboratory experiments were conducted to study the variability in the effective solubilities and activity coefficients for common constituents of gasoline fuels (benzene, toluene, p-xylene and 1,2,4-trimethylbenzene) (BTX) in matrices with an extreme range of molar volumes and chemical affinities...
September 20, 2016: Journal of Contaminant Hydrology
Patrick Höhener
BIOCHLOR is a well-known simple tool for evaluating the transport of dissolved chlorinated solvents in groundwater, ideal for rapid screening and teaching. This work extends the BIOCHLOR model for the calculation of stable isotope ratios of carbon and chlorine isotopes in chloroethenes. An exact solution for the three-dimensional reactive transport of a chain of degrading compounds including sorption is provided in a spreadsheet and applied for modeling the transport of individual isotopes (12)C, (13)C, (35)Cl, (37)Cl from a constant source...
December 2016: Journal of Contaminant Hydrology
Feike J Leij, Scott A Bradford, Antonella Sciortino
Elucidating and quantifying the transport of industrial nanoparticles (e.g. silver, carbon nanotubes, and graphene oxide) and other colloid-size particles such as viruses and bacteria is important to safeguard and manage the quality of the subsurface environment. Analytic solutions were derived for aqueous and solid phase colloid concentrations in a porous medium where colloids were subject to advective transport and reversible time and/or depth-dependent retention. Time-dependent blocking and ripening retention were described using a Langmuir-type equation with a rate coefficient that respectively decreased and increased linearly with the retained concentration...
December 2016: Journal of Contaminant Hydrology
Zhenhui Li, Cheng You, Matthew Gonzales, Anna K Wendt, Fei Wu, Susan L Brantley
Since the 1800s, natural gas has been extracted from wells drilled into conventional reservoirs. Today, gas is also extracted from shale using high-volume hydraulic fracturing (HVHF). These wells sometimes leak methane and must be re-sealed with cement. Some researchers argue that methane concentrations, C, increase in groundwater near shale-gas wells and that "fracked" wells leak more than conventional wells. We developed techniques to mine datasets of groundwater chemistry in Pennsylvania townships where contamination had been reported...
December 2016: Journal of Contaminant Hydrology
Samuel K Kumahor, Pavel Hron, George Metreveli, Gabriele E Schaumann, Sondra Klitzke, Friederike Lang, Hans-Jörg Vogel
Engineered nanoparticles released into soils may be coated with humic substances, potentially modifying their surface properties. Due to their amphiphilic nature, humic coating is expected to affect interaction of nanoparticle at the air-water interface. In this study, we explored the roles of the air-water interface and solid-water interface as potential sites for nanoparticle attachment and the importance of hydrophobic interactions for nanoparticle attachment at the air-water interface. By exposing Ag nanoparticles to soil solution extracted from the upper soil horizon of a floodplain soil, the mobility of the resulting "soil-aged" Ag nanoparticles was investigated and compared with the mobility of citrate-coated Ag nanoparticles as investigated in an earlier study...
December 2016: Journal of Contaminant Hydrology
Reynold Chow, Michael E Frind, Emil O Frind, Jon P Jones, Marcelo R Sousa, David L Rudolph, John W Molson, Wolfgang Nowak
This study addresses the delineation of areas that contribute baseflow to a stream reach, also known as stream capture zones. Such areas can be delineated using standard well capture zone delineation methods, with three important differences: (1) natural gradients are smaller compared to those produced by supply wells and are therefore subject to greater numerical errors, (2) stream discharge varies seasonally, and (3) stream discharge varies spatially. This study focuses on model-related uncertainties due to model characteristics, discretization schemes, delineation methods, and particle tracking algorithms...
December 2016: Journal of Contaminant Hydrology
Y Xiang, T Al, M Mazurek
The effect of confining pressure (CP) on the diffusion of tritiated-water (HTO) and iodide (I(-)) tracers through Ordovician rocks from the Michigan Basin, southwestern Ontario, Canada, and Opalinus Clay from Schlattingen, Switzerland was investigated in laboratory experiments. Four samples representing different formations and lithologies in the Michigan Basin were studied: Queenston Formation shale, Georgian Bay Formation shale, Cobourg Formation limestone and Cobourg Formation argillaceous limestone. Estimated in situ vertical stresses at the depths from which the samples were retrieved range from 12...
December 2016: Journal of Contaminant Hydrology
D Pedretti, A Molinari, C Fallico, S Guzzi
A series of experimental tracer tests were performed to explore the implications of the change in the pressure status of a heterogeneous bimodal aquifer for scale-dependent dispersion and mass-transfer processes. The sandbox was filled with sands and gravel channels and patches to form an alluvial-like bimodal aquifer. We performed multiple injections of a conservative tracer from 26 different locations of the sandbox and interpreted the resulting depth-integrated breakthrough curves (BTCs) at the central pumping well to obtain a scale-dependent distribution of local and field-integrated apparent longitudinal dispersivity (respectively, αL(loc) and αL(app))...
September 9, 2016: Journal of Contaminant Hydrology
Scott K Hansen, Velimir V Vesselinov
We develop empirically-grounded error envelopes for localization of a point contamination release event in the saturated zone of a previously uncharacterized heterogeneous aquifer into which a number of plume-intercepting wells have been drilled. We assume that flow direction in the aquifer is known exactly and velocity is known to within a factor of two of our best guess from well observations prior to source identification. Other aquifer and source parameters must be estimated by interpretation of well breakthrough data via the advection-dispersion equation...
September 9, 2016: Journal of Contaminant Hydrology
Débora Toledo Ramos, Helen Simone Chiaranda Lazzarin, Pedro J J Alvarez, Timothy M Vogel, Marilda Fernandes, Mário do Rosário, Henry Xavier Corseuil
The behavior of biodiesel blend spills have received limited attention in spite of the increasing and widespread introduction of biodiesel to the transportation fuel matrix. In this work, a controlled field release of biodiesel B20 (100L of 20:80 v/v soybean biodiesel and diesel) was monitored over 6.2years to assess the behavior and natural attenuation of constituents of major concern (e.g., BTEX (benzene, toluene, ethyl-benzene and xylenes) and PAHs (polycyclic aromatic hydrocarbons)) in a sandy aquifer material...
September 8, 2016: Journal of Contaminant Hydrology
Jongho Won, Robert C Borden
Soil microcosms were constructed and monitored to evaluate the impact of substrate addition and transient aerobic and anaerobic conditions on TNT, RDX and HMX biodegradation in grenade range soils. While TNT was rapidly biodegraded under both aerobic and anaerobic conditions with and without organic substrate, substantial biodegradation of RDX, HMX, and RDX daughter products was not observed under aerobic conditions. However, RDX and HMX were significantly biodegraded under anaerobic conditions, without accumulation of TNT or RDX daughter products (2-ADNT, 4-ADNT, MNX, DNX, and TNX)...
September 7, 2016: Journal of Contaminant Hydrology
Minjune Yang, Michael D Annable, James W Jawitz
Solute diffusive exchange between low-permeability aquitards and high-permeability aquifers acts as a significant mediator of long-term contaminant fate. Aquifer contaminants diffuse into aquitards, but as contaminant sources are depleted, aquifer concentrations decline, triggering back diffusion from aquitards. The dynamics of the contaminant source depletion, or the source strength function, controls the timing of the transition of aquitards from sinks to sources. Here, we experimentally evaluate three archetypical transient source depletion models (step-change, linear, and exponential), and we use novel analytical solutions to accurately account for dynamic aquitard-aquifer diffusive transfer...
September 6, 2016: Journal of Contaminant Hydrology
Mélanie Longpré-Girard, Richard Martel, Thomas Robert, René Lefebvre, Jean-Marc Lauzon
The ability of surfactant foam to enhance mobility control and LNAPL recovery in a heterogeneous porous media was investigated through sandbox experiments with p-xylene used as LNAPL. A layered heterogeneous porous media was represented in a 2D sandbox filled with two layers of coarse and medium silica sand. Based on previous tests, the surfactant solution used was Ammonyx Lo at a concentration of 0.1% (w/w). The sandbox experimental program included tracer tests done under both uncontaminated and contaminated conditions, foam injection under uncontaminated conditions and surfactant solution and foam injection under contaminated conditions...
September 3, 2016: Journal of Contaminant Hydrology
Jussi Ikonen, Mikko Voutilainen, Mervi Söderlund, Lalli Jokelainen, Marja Siitari-Kauppi, Andrew Martin
The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ...
September 2016: Journal of Contaminant Hydrology
Dan Karup, Per Moldrup, Marcos Paradelo, Sheela Katuwal, Trine Norgaard, Mogens H Greve, Lis W de Jonge
Solute transport through the soil matrix is non-uniform and greatly affected by soil texture, soil structure, and macropore networks. Attempts have been made in previous studies to use infiltration experiments to identify the degree of preferential flow, but these attempts have often been based on small datasets or data collected from literature with differing initial and boundary conditions. This study examined the relationship between tracer breakthrough characteristics, soil hydraulic properties, and basic soil properties...
September 2016: Journal of Contaminant Hydrology
Juliana Y Leung, Sanjay Srinivasan
Modeling transport process at large scale requires proper scale-up of subsurface heterogeneity and an understanding of its interaction with the underlying transport mechanisms. A technique based on volume averaging is applied to quantitatively assess the scaling characteristics of effective mass transfer coefficient in heterogeneous reservoir models. The effective mass transfer coefficient represents the combined contribution from diffusion and dispersion to the transport of non-reactive solute particles within a fluid phase...
September 2016: Journal of Contaminant Hydrology
G Bertrand, R Hirata, H Pauwels, L Cary, E Petelet-Giraud, E Chatton, L Aquilina, T Labasque, V Martins, S Montenegro, J Batista, A Aurouet, J Santos, R Bertolo, G Picot, M Franzen, R Hochreutener, G Braibant
In a context of increasing land use pressure (over-exploitation, surface-water contamination) and repeated droughts, identifying the processes affecting groundwater quality in coastal megacities of the tropical and arid countries will condition their long-term social and environmental sustainability. The present study focuses on the Brazilian Recife Metropolitan Region (RMR), which is a highly urbanized area (3,743,854 inhabitants in 2010) on the Atlantic coast located next to an estuarial zone and overlying a multi-layered sedimentary system featured by a variable sediment texture and organic content...
September 2016: Journal of Contaminant Hydrology
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