scholarly journals Environmental isotopes and noble gases in the deep aquifer system of Kazan Trona Ore Field, Ankara, central Turkey and links to paleoclimate

2013 ◽  
Vol 79 (2) ◽  
pp. 292-303 ◽  
Author(s):  
Sebnem Arslan ◽  
Hasan Yazicigil ◽  
Martin Stute ◽  
Peter Schlosser
Keyword(s):  
North Africa ◽  
Noble Gases ◽  
Noble Gas ◽  
Environmental Isotopes ◽  
Climatic Conditions ◽  
Deep Aquifer ◽  
Aquifer System ◽  
Ground Temperatures ◽  
Groundwater Samples ◽  
Central Turkey

AbstractEnvironmental isotopes and noble gases in groundwater samples from the Kazan Trona Ore Field are studied to establish the temperature change between the Holocene and the late Pleistocene. Noble gas temperatures (NGTs) presented in this study add an important facet to the global paleotemperature map in the region between Europe and North Africa. The groundwater system under investigation consists of three different aquifers named shallow, middle and deep in which δ18O and δ2H vary from − 8.10‰ to − 12.80‰ and from − 60.89‰ to − 92.60‰ VSMOW, respectively. The average isotopic depletion between unconfined and confined parts of the system is − 2.5‰ in δ18O and − 20‰ in δ2H. It is not possible to explain this depletion solely with the elevation effect. Recharge temperatures derived from dissolved atmospheric noble gases reflect the current average yearly ground temperatures (13°C) for samples collected near the recharge area but are 3 to 8°C lower than today's temperatures in the deep aquifer system. Low 14C activities and high He excesses in the confined parts of the aquifer system suggest that the water in the deep aquifer was recharged during the last Pleistocene under considerably cooler climatic conditions.

scholarly journals Environmental Isotope Study (14C, 13C, 18O, D, Noble Gases) on Deep Groundwater Circulation Systems in Hungary With Reference to Paleoclimate

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 902-918 ◽  
Author(s):  
Martin Stute ◽  
Jozsef Deak
Keyword(s):  
Cross Sections ◽  
Isotope Ratio ◽  
Noble Gases ◽  
Environmental Isotopes ◽  
Carbonate Dissolution ◽  
Deep Groundwater ◽  
Α Decay ◽  
Groundwater Circulation ◽  
Groundwater Samples ◽  
Isotope Study

We have studied environmental isotopes and noble gases in groundwater samples from various locations in the Great Hungarian Plain along two selected hydrogeological cross-sections of ca 100km. The 14C groundwater ages were corrected hydrochemically and compared with age information derived from excess helium due to 4He from α-decay of U and Th and their daughter nuclides within the aquifer and to He accumulation from the crustal (and mantle) He flux. In correcting the 14C groundwater ages, we considered carbonate dissolution under open and closed system conditions in the infiltration areas. Non-radioactive reduction of the 14C/12C isotope ratio also plays an important role due to the addition of “dead” carbon species to groundwater along its subsurface pathway. High (corrected) 14C ages, which fall into the last global cold period, are supported by significantly lower heavy stable isotope values as well as lower temperatures derived from the noble gases Ne, Ar, Kr and Xe.

scholarly journals Hydrochemical Characterisation of High-Fluoride Groundwater and Development of a Conceptual Groundwater Flow Model Using a Combined Hydrogeological and Hydrochemical Approach on an Active Volcano: Mount Meru, Northern Tanzania

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2159
Author(s):  
George Bennett ◽  
Jill Van Reybrouck ◽  
Ceven Shemsanga ◽  
Mary Kisaka ◽  
Ines Tomašek ◽  
...  
Keyword(s):  
Drinking Water ◽  
Large Scale ◽  
Active Volcano ◽  
Aquifer System ◽  
Groundwater Samples ◽  
Northern Tanzania ◽  
Different Seasons ◽  
High Fluoride ◽  
Arusha National Park ◽  
The Impact

This study characterises high-fluoride groundwater in the aquifer system on the flanks of Mount Meru, focusing on parts of the flanks that were only partially or not at all covered by previous research. Additionally, we analyse the impact of rainwater recharge on groundwater chemistry by monitoring spring discharges during water sampling. The results show that the main groundwater type in the study area is NaHCO3 alkaline groundwater (average pH = 7.8). High F− values were recorded: in 175 groundwater samples, the concentrations range from 0.15 to 301 mg/L (mean: 21.89 mg/L, median: 9.67 mg/L), with 91% of the samples containing F− values above the WHO health-based guideline for drinking water (1.5 mg/L), whereas 39% of the samples have Na+ concentrations above the WHO taste-based guideline of 200 mg/L. The temporal variability in F− concentrations between different seasons is due to the impact of the local groundwater recharge. We recommend that a detailed ecohydrological study should be carried out for the low-fluoride springs from the high-altitude recharge areas on the eastern and northwestern flanks of Mount Meru inside Arusha National Park. These springs are extracted for drinking purposes. An ecohydrological study is required for the management of these springs and their potential enhanced exploitation to ensure the sustainability of this water extraction practice. Another strategy for obtaining safe drinking water could be to use a large-scale filtering system to remove F− from the groundwater.

Liquid noble gases for dark matter searches: An updated survey

2015 ◽  
Vol 30 (26) ◽  
pp. 1530053 ◽  
Author(s):  
R. Bernabei ◽  
P. Belli ◽  
A. Incicchitti ◽  
F. Cappella ◽  
R. Cerulli
Keyword(s):  
Dark Matter ◽  
Noble Gases ◽  
Noble Gas ◽  
Low Energy ◽  
Gas Detectors ◽  
Double Phase ◽  
Methodological Comparison ◽  
Direct Dark Matter ◽  
Energy Physics

An updated technical and methodological comparison of liquid noble gas experiments is presented with particular attention to the low energy physics application of double-phase noble gas detectors in direct Dark Matter investigations.

scholarly journals Hydrogeochemical Properties Providing Links to Methanogenesis in Deep Aquifer of Bhola Island, Bangladesh

2019 ◽  
Vol 45 (2) ◽  
pp. 217-228
Author(s):  
Masuma Chowdhury ◽  
Sarmin Sultana ◽  
Md Atikul Islam ◽  
Aziz Hasan ◽  
Kazi Matin Uddin Ahmed
Keyword(s):  
Geothermal Gradient ◽  
Water Type ◽  
Gas Generation ◽  
Deep Aquifer ◽  
Upward Migration ◽  
Methane Generation ◽  
Biogenic Methane ◽  
Low Concentrations ◽  
Groundwater Samples ◽  
Favourable Environment

This paper compares the hydrogeochemical signatures between naturally flowing wells with methane (FWs) and non-flowing wells (require pumping) without methane (NFWs) by analyzing a total of 59 groundwater samples to find possible links for methane gas generation. Relatively higher concentration of HCO3 ⁻ indicates oxidation of organic matter (OM) for both the cases which is corroborated by the dominance of Na-Mg-HCO3 and Na- Mg-HCO3-Cl water type. Low concentrations of redox sensitive parameters i.e., NO3 ⁻, SO4 2⁻, Fe2+ and Mn2+ are indicating prevalence of extremely reducing condition and relatively lower concentrations of SO₄²⁻ in FWs suggest microbial sulphate reduction reaching final stage of redox ladder i.e., methanogenesis. Comparatively higher temperature and subsequent higher electrical conductivity (EC) in FWs possibly attributed by the chemical reactions of methane generation or vice versa. Low geothermal gradient, presence of OM and distribution of the FWs over a paleo valley in the deep confined aquifer zone refer to the existence of favourable environment for biogenic methane production rather than the upward migration or leakage of thermogenic gas from the reservoir below. Asiat. Soc. Bangladesh, Sci. 45(2): 217-228, December 2019

scholarly journals Emission of Noble Gases Binary Mixtures under Excitation by the Products of the 6Li (n, α)3 H Nuclear Reaction

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Kuanysh Samarkhanov ◽  
Mendykhan Khasenov ◽  
Erlan Batyrbekov ◽  
Inesh Kenzhina ◽  
Yerzhan Sapatayev ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Nuclear Energy ◽  
Alkali Metals ◽  
Nuclear Reactor ◽  
Noble Gases ◽  
Noble Gas ◽  
Direct Conversion ◽  
Reaction Products ◽  
Gas Molecules ◽  
Sodium And Potassium

The luminescence of Kr-Xe, Ar-Kr, and Ar-Xe mixtures was studied in the spectral range 300–970 nm when excited by 6Li (n, α)3 H nuclear reaction products in the core of a nuclear reactor. Lithium was deposited on walls of experimental cell in the form of a capillary-porous structure, which made it possible to measure up to a temperature of 730 K. The temperature dependence of the radiation intensity of noble gas atoms, alkali metals, and heteronuclear ionic noble gas molecules was studied. Also, as in the case of single-component gases, the appearance of lithium lines and impurities of sodium and potassium is associated with vaporization during the release of nuclear reaction products from the lithium layer. The excitation of lithium atoms occurs mainly as a result of the Penning process of lithium atoms on noble gas atoms in the 1s states and subsequent ion-molecular reactions. Simultaneous radiation at transitions of atoms of noble gases and lithium, heteronuclear ion molecules of noble gases allows us to increase the efficiency of direct conversion of nuclear energy into light.

scholarly journals Leading Interaction Components in the Structure and Reactivity of Noble Gases Compounds

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2367
Author(s):  
Francesca Nunzi ◽  
Giacomo Pannacci ◽  
Francesco Tarantelli ◽  
Leonardo Belpassi ◽  
David Cappelletti ◽  
...  
Keyword(s):  
Chemical Bond ◽  
Theoretical Approach ◽  
Noble Gases ◽  
Halogen Bond ◽  
Noble Gas ◽  
Anomalous Behavior ◽  
Type Interaction ◽  
Long Life ◽  
Weak Chemical

The nature, strength, range and role of the bonds in adducts of noble gas atoms with both neutral and ionic partners have been investigated by exploiting a fine-tuned integrated phenomenological–theoretical approach. The identification of the leading interaction components in the noble gases adducts and their modeling allows the encompassing of the transitions from pure noncovalent to covalent bound aggregates and to rationalize the anomalous behavior (deviations from noncovalent type interaction) pointed out in peculiar cases. Selected adducts affected by a weak chemical bond, as those promoting the formation of the intermolecular halogen bond, are also properly rationalized. The behavior of noble gas atoms excited in their long-life metastable states, showing a strongly enhanced reactivity, has been also enclosed in the present investigation.

scholarly journals Noble Gases in Terrestrial Planets: Evidence for Cometary Impacts?

1989 ◽  
Vol 116 (1) ◽  
pp. 429-437
Author(s):  
Tobias Owen ◽  
Akiva Bar-Nun ◽  
Idit Kleinfeld
Keyword(s):  
Low Temperatures ◽  
Noble Gases ◽  
Noble Gas ◽  
Terrestrial Planets ◽  
Laboratory Studies ◽  
The Impact ◽  
Gas Patterns ◽  
Atmosphere Of Venus

AbstractThe possible role of comets in bringing volatiles to the inner planets is investigated by means of laboratory studies of the ability of ice to trap gases at low temperatures. The pattern of the heavy noble gases formed in the atmosphere of Venus can be explained by the impact of a planetesimal composed of ices formed in the range of 20 to 30 K. The noble gas patterns on Mars and Earth are less explicable by cometary bombardment alone.

scholarly journals Microbial Community and Atrazine-Degrading Genetic Potential in Deep Zones of a Hypersaline Lake-Aquifer System

2020 ◽  
Vol 10 (20) ◽  
pp. 7111
Author(s):  
Yolanda Espín ◽  
Giuliana Aranzulla ◽  
Manuel Álvarez-Ortí ◽  
Juan José Gómez-Alday
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
16S Rrna Gene Sequencing ◽  
Unconfined Aquifer ◽  
Hypersaline Lake ◽  
Rrna Gene ◽  
Deep Aquifer ◽  
Aquifer System ◽  
Genetic Potential ◽  
Atrazine Degradation

The chemical composition of groundwater and related surface water ecosystems can be modified by intensive agricultural activities. This is the case of the Natural Reserve of Pétrola saline lake (Albacete, SE Spain), which constitutes the discharge area of an unconfined aquifer. The extended use of fertilizers and pesticides poses a threat to ecosystem sustainability. One of the most applied herbicides worldwide has been atrazine. Despite being prohibited in Spain since 2007 by European regulations, atrazine can still be detected due to its high persistence in the environment. Atrazine degradation pathways are mediated by biological processes performed by microorganisms with adapted metabolic mechanisms that make in situ bioremediation possible. To evaluate the presence of such microorganisms in the unconfined aquifer, groundwater was collected from a flowing 37.9 m deep piezometer. DNA was extracted, and the bacterial 16S rRNA gene was amplified and cloned. Later, 93 clones were sequenced, providing the first molecular assessment of bacterial community structure in the deep zones of the aquifer. Some of these bacteria have been previously described to be involved in atrazine degradation. In addition, 14 bacteria were isolated from the groundwater samples and identified by 16S rRNA gene sequencing. DNA from these bacteria was subjected to PCR assays with primers designed for the genes involved in the atrazine degradation pathway. Positive results in the amplification were found in at least three of these bacteria (Arthrobacter sp., Nocardioides sp. and Pseudomonas sp.). The atrazine-degrading genetic potential was shown to be dependent on the trzN and atzA,B,C gene combination. These results suggest for the first time the adaptation of the bacterial population present in deep aquifer zones to atrazine exposure, even after more than 15 years of its ban in Spain. In addition, this study provides the baseline data about the bacterial communities found in deep aquifer zones from the hypersaline lake-aquifer system.

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