Read by QxMD icon Read

Ground Water

Mohamad R Soltanian, Mohammad A Amooie, David R Cole, Thomas H Darrah, David E Graham, Susan M Pfiffner, Tommy J Phelps, Joachim Moortgat
In the context of geological carbon sequestration (GCS), carbon dioxide (CO2 ) is often injected into deep formations saturated with a brine that may contain dissolved light hydrocarbons, such as methane (CH4 ). In this multicomponent multiphase displacement process, CO2 competes with CH4 in terms of dissolution, and CH4 tends to exsolve from the aqueous into a gaseous phase. Because CH4 has a lower viscosity than injected CO2 , CH4 is swept up into a 'bank' of CH4 -rich gas ahead of the CO2 displacement front...
January 16, 2018: Ground Water
Thomas H Darrah
No abstract text is available yet for this article.
January 16, 2018: Ground Water
Wenjing Qiao, Shujun Ye, Jichun Wu, Ming Zhang
Remediation of the sites contaminated with organic contaminants, such as chlorobenzenes, remains a challenging issue. Electroosmotic flushing can be a promising approach which is based on mechanism of electrokinetic remediation for removal of organic contaminants from fluids in low-permeability soil. To select an optimum surfactant that can effectively enhance electroosmotic flushing, three common surfactants, Triton X-100 (EK2), Tween 80 (EK3), and a mixture of sodium dodecyl sulfate and Triton X-100 (EK4) buffered with Na2 HPO4 /NaH2 PO4 solution, were tested...
January 10, 2018: Ground Water
Michael Rona, Ovadia Lev, Haim Gvirtzman
A 3-dimensional hydrologic groundwater flow and contaminant transport model was developed to address the feasibility and relevant time-scales for remediation of a large soil aquifer treatment (SAT) site for domestic wastewater. The model accounted for a range of organic pollutant retardation factors and biodegradation kinetics. In order to detect the effect of the most retained and the most refracted/recalcitrant pollutants, it was crucial to model fractions of different properties rather than with average set properties...
December 29, 2017: Ground Water
Sorab Panday, Vivek Bedekar, Christian D Langevin
A groundwater flow model is typically used to provide the flow field for conducting groundwater solute transport simulations. The advection term of the mass conserved formulation for groundwater transport assumes that the flow field is perfectly balanced and that all water flowing into a numerical grid cell is exactly balanced by outflows after accounting for sources/sinks or internal storage. However, in many complicated regional or site-scale models, there may be localized flow balance errors that may be difficult to eliminate through tighter flow convergence tolerances due to simulation time constraints or numerical limits on convergence tolerances...
December 22, 2017: Ground Water
Thomas Wöhling, Moritz J Gosses, Scott R Wilson, Peter Davidson
New Zealand's gravel-bed rivers have deposited coarse, highly conductive gravel aquifers that are predominantly fed by river water. Managing their groundwater resources is challenging because the recharge mechanisms in these rivers are poorly understood and recharge rates are difficult to predict, particularly under a more variable future climate. To understand the river-groundwater exchange processes in gravel-bed rivers, we investigate the Wairau Plain Aquifer using a three-dimensional groundwater flow model which was calibrated using targeted field observations, "soft" information from experts of the local water authority, parameter regularization techniques, and the model-independent parameter estimation software PEST...
December 21, 2017: Ground Water
Rahim Bagheri, Hadi Jafari, Fatemeh Bagheri
Badab Sourt travertine-depositing springs in the north of Iran, naturally create a unique surreal landscape containing a range of stepped travertine terraces, similarly found only in a few other places on earth. This site comprises of three travertine saline springs with different values of salinity and discharge (SP1 , SP2 , and SP3 ) and one non-travertine fresh karstic spring (SP4 ) within a distance of about 300 m. The etiology behind this salinity and the water origin are the main research's dilemma that were investigated using geological, hydrochemical, and stable isotopic techniques...
December 14, 2017: Ground Water
Jens Schumacher, Kevin Hayley, Louis-Charles Boutin, Emma White
No abstract text is available yet for this article.
December 8, 2017: Ground Water
Qiang Wu, Yingwang Zhao, Yu-Feng F Lin, Hua Xu, Hanxiong Zhang
The continuous Galerkin finite element method is commonly considered locally nonconservative because a single element with fluxes computed directly from its potential distribution is unable to conserve its mass and fluxes across edges that are discontinuous. Some literature sources have demonstrated that the continuous Galerkin method can be locally conservative with postprocessed fluxes. This paper proposes the concept of a direct conservative domain (DCD), which could conserve mass when fluxes are computed directly from the potential distribution...
December 1, 2017: Ground Water
Mohammad Taghi Sattari, Rasoul Mirabbasi, Reza Shamsi Sushab, John Abraham
The Ardebil plain, which is located in northwest Iran, has been faced with a recent and severe decline in groundwater level caused by a decrease of precipitation, successive long-term droughts, and overexploitation of groundwater for irrigating the farmlands. Predictions of groundwater levels can help planners to deal with persistent water deficiencies. In this study, the support vector regression (SVR) and M5 decision tree models were used to predict the groundwater level in Ardebil plain. The monthly groundwater level data from 24 piezometers for a 17-year period (1997 to 2013) were used for training and test of models...
November 29, 2017: Ground Water
Mariana Gómez-Nicolás, Mario Rebolledo-Vieyra, Efrain Canto-Lugo, Rodrigo Huerta-Quintanilla, Pablo Ochoa-Sandoval
The Ring of Cenotes (RC) is an alignment of numerous cenotes (sinkholes) in a semicircular form (with a radius of 100 km) located in northwestern Yucatán, México. The formation roughly coincides with a concentric ring that corresponds to a buried structure, which has been identified as the product of a meteor impact, known as the Chicxulub crater. Secondary permeability generated by the fracturing and faulting of the sedimentary sequence in the Chicxulub crater has favored the karstification process and therefore the development of underground rivers that transport water from the mainland to the sea...
November 29, 2017: Ground Water
Mary Jo Baedecker, Robert P Eganhouse, Haiping Qi, Isabelle M Cozzarelli, Jared J Trost, Barbara A Bekins
The composition of crude oil in a surficial aquifer was determined in two locations at the Bemidji, MN, spill site. The abundances of 71 individual hydrocarbons varied within 16 locations sampled. Little depletion of these hydrocarbons (relative to the pipeline oil) occurred in the first 10 years after the spill, whereas losses of 25% to 85% of the total measured hydrocarbons occurred after 30 years. The C6-30 n-alkanes, toluene, and o-xylene were the most depleted hydrocarbons. Some hydrocarbons, such as the n-C10-24 cyclohexanes, tri- and tetra- methylbenzenes, acyclic isoprenoids, and naphthalenes were the least depleted...
November 29, 2017: Ground Water
Muhammad Hasan, Yanjun Shang, Gulraiz Akhter, Weijun Jin
An integrated study using geophysical method in combination with pumping tests and geochemical method was carried out to delineate groundwater potential zones in Mian Channu area of Pakistan. Vertical electrical soundings (VES) using Schlumberger configuration with maximum current electrode spacing (AB/2 = 200 m) were conducted at 50 stations and 10 pumping tests at borehole sites were performed in close proximity to 10 of the VES stations. The aim of this study is to establish a correlation between the hydraulic parameters obtained from geophysical method and pumping tests so that the aquifer potential can be estimated from the geoelectrical surface measurements where no pumping tests exist...
November 17, 2017: Ground Water
Dylan J Irvine
No abstract text is available yet for this article.
November 16, 2017: Ground Water
Yizhi Sheng, Guangcai Wang, Dan Zhao, Chunbo Hao, Chenglong Liu, Linfeng Cui, Ge Zhang
Spatial distribution (horizonal and vertical) of groundwater microbial communities and the hydrogeochemistry in confined aquifers were studied approximately along the groundwater flow path from coteau to plain in the Nomhon area, Qinghai-Tibet plateau, China. The confined groundwater samples at different depths and locations were collected in three boreholes through a hydrogeological section in this arid and semi-arid area. The phylogenetic analysis of 16S rRNA genes and multivariate statistical analysis were used to elucidate similarities and differences between groundwater microbial communities and hydrogeochemical properties...
November 9, 2017: Ground Water
Xun Zhou, Xiaocui Wang, Jiajun Han, Qin Cao, Changlong Jiang, Juan Guo, Haiyan Zhou
Subsurface K-rich brines are important mineral resources for fertilizer production while the evolution of such brines is poorly documented. In the Sichuan Basin in southwest China, they are found mainly in the Middle and Lower Triassic marine carbonate aquifers. Total dissolved solids of the brines range from 176 to 378 g/L and K concentrations, from 1.9 to 53.3 g/L. We found that the brines are mainly of Cl-Na type, while Ba is absent in the brines. Comparison of the brine samples with both the trajectories of ions and the newly proposed trajectories of ion ratios of evaporated seawater suggests that the brines are enriched in Ca, Sr, Li, and I, depleted in SO4 and Mg, and neither enriched nor depleted in Cl and Na...
November 9, 2017: Ground Water
David Deming
No abstract text is available yet for this article.
November 9, 2017: Ground Water
Randal J Barnes
When is the impact of a sloping base large enough to justify more complex models for an unconfined aquifer? The intuitive answer that "it depends on the magnitude of the slope" is not wholly correct. Using recent mathematical results (the Lambert W function), we explicitly solve the simple sloping base problem. This explicit solution offers insights beyond those possible using Dupuit's, Polubarinov-Kochina's, Harr's, Child's, and others' implicit solutions. Specifically, it shows that the impact of the sloping base is best characterized by the saturated thickness divided by the change in base elevation, not by the slope...
November 9, 2017: Ground Water
Venkataramana Sridhar, Mirza M Billah, John W Hildreth
Many current watershed modeling efforts now incorporate surface water and groundwater for managing water resources since the exchanges between groundwater and surface water need a special focus considering the changing climate. The influence of groundwater dynamics on water and energy balance components is investigated in the Snake River Basin (SRB) by coupling the Variable Infiltration Capacity (VIC) and MODFLOW models (VIC-MF) for the period of 1986 through 2042. A 4.4% increase in base flows and a 10.3% decrease in peak flows are estimated by VIC-MF compared to the VIC model in SRB...
November 9, 2017: Ground Water
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"