SHALLOW GROUNDWATER HYDRO-CHEMICAL EVOLUTION AND SIMULATION WITH SPECIAL FOCUS ON GUANZHONG BASIN, CHINA

2013 ◽  
Vol 12 (7) ◽  
pp. 1447-1455 ◽  
Author(s):  
Wenke Wang ◽  
Lei Duan ◽  
Xiaoting Yang ◽  
Hua Tian
Keyword(s):  
Chemical Evolution ◽  
Shallow Groundwater ◽  
Special Focus ◽  
Guanzhong Basin

Chemical evolution of shallow groundwater along the northeast shore of Mono Lake, California

1995 ◽  
Vol 31 (12) ◽  
pp. 3171-3182 ◽  
Author(s):  
Tracy L. Connell ◽  
Shirley J. Dreiss
Keyword(s):  
Chemical Evolution ◽  
Shallow Groundwater ◽  
Mono Lake

scholarly journals Shallow groundwater chemical evolution, isotopic hyperfiltration, and salt pan formation in a hypersaline endorheic basin: Pilot Valley, Great Basin, USA

2021 ◽  
Author(s):  
A. L. Mayo ◽  
D. G. Tingey
Keyword(s):  
Great Basin ◽  
Chemical Evolution ◽  
Isotopic Fractionation ◽  
Shallow Groundwater ◽  
Alluvial Fan ◽  
Mineral Dissolution ◽  
Driving Mechanism ◽  
Evaporative Water ◽  
Salt Pan ◽  
Endorheic Basin

AbstractEndorheic basin brines are of economic significance as sources of boron, iodine, magnesium, potassium, sodium sulfate, sodium carbonate, and tungsten, and they are a major source of the critical metal lithium. Although evaporation is the primary hypersalinization driver for evaporative water bodies, recent investigations have proposed more novel mechanisms for some subsurface brine. This investigation explores shallow groundwater hypersalinization. The chemical evolution and isotopic fractionation of shallow hypersaline groundwater in the clay-rich arid endorheic basin sediments of Pilot Valley, Great Basin (USA), were investigated. Groundwater evolves from fresh in the mountain bedrock and alluvial fans, to brackish and saline at the alluvial fan–playa interface, and to hypersaline in the upper 12 m of basin sediments. Alluvial fan systems are isolated from each other and have varying groundwater 3H and 14C travel times. Nonevaporative in-situ isotopic fractionation of up to −8‰ in δ18O is attributed to clay sequence hyperfiltration. Groundwater flow-path sulfate and chloride mineral dissolution is the primary driving mechanism for both interface and basin groundwater evolution. Evaporation only impacts the groundwater quality in a small portion of the basin where the groundwater is within ~1 m of the ground surface. Here capillary action carries dissolved soluble salts to the land surface. Episodic flooding redissolves and carries the precipitated salt to the annually flooded salt pan where it accumulates as a salt crust during the dry season. The Pilot Valley model may help explain the buildup accumulative layers of soluble salt that when remobilized becomes subsurface brine.

scholarly journals Hydrogeochemical Characterization and Irrigation Quality Assessment of Shallow Groundwater in the Central-Western Guanzhong Basin, China

2019 ◽  
Vol 16 (9) ◽  
pp. 1492 ◽  
Author(s):  
Panpan Xu ◽  
Wenwen Feng ◽  
Hui Qian ◽  
Qiying Zhang
Keyword(s):  
Water Samples ◽  
Shallow Groundwater ◽  
Hydrochemical Facies ◽  
Rock Weathering ◽  
Entire Study ◽  
Salinity Hazard ◽  
Groundwater Samples ◽  
Guanzhong Basin ◽  
Irrigation Quality ◽  
Wei River

Groundwater is the major water resource for the agricultural development of the Guanzhong Basin, China. In this study, a total of 97 groundwater samples (51 from the North Bank of the Wei River (NBWR) and 46 from the South Bank of the Wei River (SBWR)) were collected from the central-western Guanzhong Basin. The aim of this study was to investigate the hydrogeochemical characteristics of the basin and to determine the suitability of shallow groundwater for irrigation. The groundwater of the entire study area is alkaline. The groundwater of the SBWR is fresh water, and the NBWR groundwater is either freshwater or brackish water. The average concentration of ions (except for Ca2+) in SBWR samples is lower than in NBWR samples. HCO3− is dominant in the groundwater of the study area. Ca2+ is dominant in the SBWR while Na+ is dominant in the NBWR. The SBWR groundwater is mainly of the HCO3-Ca·Mg type, and has undergone the main hydrogeochemical processes of rock weathering-leaching. The hydrochemical facies of the majority of the NBWR groundwater samples are the HCO3-Na type with several minor hydrochemical facies of the HCO3-Ca·Mg, SO4·Cl-Na, and SO4·Cl-Ca·Mg types. Its chemistry is mainly controlled by rock weathering, cation exchange, and evaporation. Salinity hazard, sodium percentage, sodium adsorption ratio, residual sodium carbonate, magnesium hazard, permeability index, Kelley’s ratio, potential salinity, synthetic harmful coefficient, and irrigation coefficient were assessed to evaluate the irrigation quality of groundwater. The results of the comprehensive consideration of these indicators indicate that the percentage of NBWR water samples suitable for irrigation purposes ranges between 15.7% and 100% at an average level of 56.7%. Of the SBWR water samples suitable for irrigation, the percentage ranges from 78.3% to 100% with an average of 91.8%. Land irrigated with such water will not be exposed to any alkali hazard, but will suffer from a salinity hazard, which is more severe in the NBWR. Thus, most of the water in the NBWR can be used for soils with good drainage conditions which control salinity.

scholarly journals Environmental Hazards of an Unrecultivated Liquid Waste Disposal Site on Soil and Groundwater

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 226
Author(s):  
Tamás Mester ◽  
György Szabó ◽  
Zsófi Sajtos ◽  
Edina Baranyai ◽  
Gergely Szabó ◽  
...  
Keyword(s):  
Waste Disposal ◽  
Significant Risk ◽  
Liquid Waste ◽  
Shallow Groundwater ◽  
Environmental Hazards ◽  
Disposal Site ◽  
Special Focus ◽  
Engineering Controls ◽  
Infiltration Basin ◽  
High Level

Disposal sites without adequate engineering controls pose a significant risk to the environment. In the present study, the environmental hazards of an abandoned and unrecultivated liquid waste disposal are investigated with a special focus on soil and shallow groundwater contamination. After a period of operation from 1994 to 2010, when the wastewater collection of the municipality was regulated, the disposal site was subsequently decommissioned without further action. Eight monitoring wells have been established in the disposal basins and in the surrounding area to determine the contamination of the site. Sampling took place in the summers of 2020 and 2021. The results of the analysis of the soil and water samples collected showed a high level of contamination in the area. In the borehole profile of the infiltration basin, a well-developed leachate nitrate profile was observed, with a concentration above 3000 mg/kg NO3−. The soil phosphate content was also significant, with a value of over 1900 mg/kg in the upper 40 cm layer. Extremely high concentrations of ammonium (>45 mg/L) and organic matter (>90 mg/L) were detected in the groundwater of the basins, indicating that contaminated soil remains a major source of pollutants more than 10 years after closure. For all micro- and macroelements present in detectable concentrations, a significant increase was observed in the infiltration basin. Our results have revealed that the surroundings are also heavily contaminated. NO3− concentrations above the contamination limit were measured outside the basins. Recultivation of liquid waste disposal sites of similar characteristics is therefore strongly recommended.

scholarly journals Chemical evolution of shallow groundwater as recorded by springs, Sagehen basin; Nevada County, California

2001 ◽  
Vol 179 (1-4) ◽  
pp. 37-51 ◽  
Author(s):  
Laura K Rademacher ◽  
Jordan F Clark ◽  
G.Bryant Hudson ◽  
Don C Erman ◽  
Nancy A Erman
Keyword(s):  
Chemical Evolution ◽  
Shallow Groundwater

Current concepts of the interventional treatment of proximal supraaortic vessel stenosis

VASA ◽  
2012 ◽  
Vol 41 (5) ◽  
pp. 313-318 ◽  
Author(s):  
Ernemann ◽  
Bender ◽  
Melms ◽  
Brechtel ◽  
Kobba ◽  
...  
Keyword(s):  
Treatment Strategies ◽  
Carotid Bifurcation ◽  
Current Treatment ◽  
Long Term Results ◽  
Clinical Indication ◽  
Interventional Treatment ◽  
Special Focus ◽  
Brachiocephalic Artery ◽  
Treatment Concepts ◽  
Angioplasty And Stenting

Interventional therapies using angioplasty and stenting of symptomatic stenosis of the proximal supraaortic vessels have evolved as safe and effective treatment strategies. The aim of this paper is to summarize the current treatment concepts for stenosis in the subclavian and brachiocephalic artery with regard to clinical indication, interventional technique including selection of the appropriate vascular approach and type of stent, angiographic and clinical short-term and long-term results and follow-up. The role of hybrid interventions for tandem stenoses of the carotid bifurcation and brachiocephalic artery is analysed. A systematic review of data for angioplasty and stenting of symptomatic extracranial vertebral artery stenosis is discussed with a special focus on restenosis rate.

Social Psychology and Noninvasive Electrical Stimulation

2016 ◽  
Vol 21 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Paulo S. Boggio ◽  
Gabriel G. Rêgo ◽  
Lucas M. Marques ◽  
Thiago L. Costa
Keyword(s):  
Social Psychology ◽  
Social Neuroscience ◽  
Special Focus ◽  
Social Pain ◽  
Substantial Evidence ◽  
Social Decision ◽  
Correlational Research ◽  
Neuroscience Research ◽  
Social Decision Making ◽  
Brain Behavior

Abstract. Social neuroscience and psychology have made substantial advances in the last few decades. Nonetheless, the field has relied mostly on behavioral, imaging, and other correlational research methods. Here we argue that transcranial direct current stimulation (tDCS) is an effective and relevant technique to be used in this field of research, allowing for the establishment of more causal brain-behavior relationships than can be achieved with most of the techniques used in this field. We review relevant brain stimulation-aided research in the fields of social pain, social interaction, prejudice, and social decision-making, with a special focus on tDCS. Despite the fact that the use of tDCS in Social Neuroscience and Psychology studies is still in its early days, results are promising. As better understanding of the processes behind social cognition becomes increasingly necessary due to political, clinical, and even philosophical demands, the fact that tDCS is arguably rare in Social Neuroscience research is very noteworthy. This review aims at inspiring researchers to employ tDCS in the investigation of issues within Social Neuroscience. We present substantial evidence that tDCS is indeed an appropriate tool for this purpose.

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