Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Geochemistry
Type of Medium
Language
Year
  • 1
    Language: English
    In: Applied Geochemistry, 2008, Vol.23(10), pp.2945-2954
    Description: Naturally occurring stable and radioactive isotopes were used as environmental tracers to investigate contaminant metal mobilization processes in a metal smelter dump mainly consisting of slag. Water emerging from the dump at a spring is heavily contaminated by metals. The smelter dump contains minor amounts of flue dust, a material which shows a high potential for metal mobilization. Nearby dumps mainly consist of low-grade ore. Concentration patterns of U, Ra and Pb determined in sediment deposited close to the contaminated spring reveal the flue dust to be the major local metal source rather than the slag or the low-grade ore. Contamination pathways inside the dump were investigated using hydrological, chemical and isotopic data. Strong negative correlation between water discharge and metal concentration in the spring water suggests, besides short-term dilution of the metal concentration by direct rainwater runoff, distinct long-term dilution of the spring water by groundwater being discharged at a significantly increased rate as a result of heavy rains. δ O and δD signatures of rain, local groundwater and spring water confirm the importance of groundwater derived from the local aquifer. Another hydrological component with importance for metal mobilization was found to be water that is recharged in the dump itself. Tritium analysis allowed an assessment of the probable residence time of that water component in the smelter dump. Since that water component seems to represent a major local contamination pathway the findings of the study are of substantial importance for site remediation planning. As a primary result it could be stated that covering the dump would not result in any noteworthy short-term improvement of the spring water quality. First significant effects would only be visible after 2–3 decades at the earliest.
    Keywords: Geology
    ISSN: 0883-2927
    E-ISSN: 1872-9134
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Journal of Hydrology, 2011, Vol.402(3), pp.274-289
    Description: ► Using multiple isotopes to study groundwater flow in active rifts. ► Hydrochemical and isotopic evolution from escarpments to Rift floor. ► Mantle CO influences groundwater hydrochemistry. ► Apparent C ages are similar in Rift floor groundwater. ► Groundwater flow paths occur both longitudinal and transversal to rift axis. This study aims to investigate groundwater recharge and flow patterns in tectonically active rift systems, exemplified by a case study in the Main Ethiopian Rift. The chosen approach includes the investigation of hydrochemical parameters and environmental isotopes ( H, δ H, δ O, δ C-DIC, C-DIC, Sr/ Sr). Apparent groundwater ages were determined by radiocarbon dating after correction of C-DIC using a modified δ C-mixing model and further validation using geochemical modelling with NETPATH. Hydrochemical and isotopic data indicate an evolutionary trend existing from the escarpments towards the Rift floor. Groundwater evolves from tritium-containing and hence recently recharged Ca–HCO -type water on the escarpments to tritium-free Na–HCO groundwater dominating deep Rift floor aquifers. Correspondingly, rising pH and values coupled with increasingly enriched δ C signatures point to hydrochemical evolution of DIC and beginning dilution of the carbon isotope signature by other carbon sources, related to a diffuse influx of mantle CO into the groundwater system. Especially thermal groundwater sampled near the most recent fault zones in the Fantale/Beseka region displays clear influence of mantle CO and increased water–rock interaction, indicated by a shift in δ C and Sr/ Sr signatures. The calculation of apparent groundwater ages revealed an age increase of deep groundwater from the escarpments to the Rift floor, complying with hydrochemical evolution. Within the Rift, samples show a relatively uniform distribution of apparent C ages of ∼1800 to ∼2800 years, with the expected down-gradient aging trend lacking, contradicting the predominant intra-rift groundwater flow described in existing transect-based models of groundwater flow. By combining hydrochemical and new isotopic data with knowledge of the structural geology of the Rift, we improve the existing groundwater flow model and propose a new conceptual model by identifying flow paths both transversal and longitudinal to the main Rift axis, the latter being strongly controlled by faulted and tilted blocks on the escarpment steps. The connection between groundwater flow and fault direction make this model applicable to other active rift systems with similar structural settings.
    Keywords: Rift Tectonics ; Hydrochemistry ; Isotope Hydrology ; Groundwater Cycle and Dating ; 87sr/ 86sr ; 14c ; Geography
    ISSN: 0022-1694
    E-ISSN: 1879-2707
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Science of the Total Environment, 2008, Vol.398(1), pp.164-174
    Description: Seven years of monitoring groundwater in the Gaza Strip has shown that nitrate was and still is a major groundwater pollutant. The objectives of this research were to study the distribution of NO in the groundwater of the Gaza Strip and to identify the sources of NO in the Gaza aquifer system by assessing nitrogen and oxygen isotopes. The most recent samples collected in 2007 showed 90% of the wells having NO concentrations that are several times higher than the WHO standards of 50 mg/L. Potential NO source materials in Gaza are animal manure N, synthetic NH based fertilizers, and wastewater/sludge. The average concentrations of N in the sludge, manure and soil of Gaza were 2.9%, 1% and 0.08%, respectively. The range in N of solid manure samples was + 7.5 to + 11.9‰. The range in N of sludge samples was + 4.6 to + 7.4‰, while four brands of synthetic fertilizers commonly used in Gaza had N ranging from + 0.2 to + 1.0‰. Sludge amended soil had N ranging from + 2.0 to + 7.3‰. For both O and N, the ranges of groundwater NO were − 0.1 to + 9.3‰ and + 3.2 to 12.8‰, respectively. No significant bacterial denitrification is taking place in the Gaza Strip aquifer. Nitrate was predominantly derived from manure and, provided N of sludge represents the maximum N of human waste, to a lesser extent from septic effluents/sludge. Synthetic fertilizers were a minor source.
    Keywords: Gaza Strip ; Nitrate ; Nitrogen/Oxygen Isotopes ; Environmental Sciences ; Biology ; Public Health
    ISSN: 0048-9697
    E-ISSN: 1879-1026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Quaternary International, 04 August 2014, Vol.338, pp.59-70
    Description: Miocene–Pliocene and Upper Cretaceous formations in Tunisia contain one of the most productive artesian aquifers in the country. They consist of Mio-Pliocene sands and Senonian/Turonian carbonates. Intensive pumping in Kébili and Nefzaoua regions over the past decades resulted in gradual lowering of water table at the rate of approximately 0.85 m y . Forty-two groundwater samples have been collected from different sectors of the studied aquifers for chemical and isotopic analyses. The observed large spatial variability of chemical composition of groundwater in the study area is most probably linked to two processes: (i) dissolution of dolomite and gypsum, combined with calcite precipitation (dedolomitisation), and (ii) partial evaporation of water. The first process plays an important role in the study area due to abundance of evaporites. Partial evaporation occurs in the upper part of the unsaturated zone during infiltration, especially for groundwater sampled in the Kebili and Djerid regions. Apart from these processes, there are others which influence the salinity of the aquifers. In the Mio-Pliocene aquifer, which behaves as an open system to gases and which receives inputs of CO gas derived from intensive tectonic activity in the area, the interaction of carbon dioxide with carbonate matrix of the aquifer produces an increase in the alkalinity of water. In the Senonian and Turonian aquifers, the process of dedolomitisation evolves in a closed system with respect to CO gas. Ca /Na cation exchange and halite dissolution processes are also important. Stable isotope composition of water (δ O, δ H) indicates that the recharge occurs from the Dahar upland. The C activity varies between 89.5 (±1.5) and 3.7 (±2.1) pmc. The C content in the total dissolved inorganic carbon (TDIC) range between −13.9 and −3.6‰. The calculated concentrations of C in the CO gas in equilibrium with the TDIC vary between −22 and −11‰, indicating two sources of carbon in the solution: carbonate matrix (δ C = −2‰) and soil CO (δ C from −25 to −21‰ for the cultivated areas). Mean residence times of water have been determined after correction of the initial C activities for C-dilution processes including carbonate dissolution, calcite precipitation and cation-exchange. The dilution processes were quantified on the basis of geochemical and C mass balance equations. The calculated mean residence times of water confirm modern recharge from Dahar upland and the mountains surrounding depressions, and indicate the presence of paleowaters in the east and south-west region, and in the discharge zone.
    Keywords: Tunisia ; Dissolution ; Evaporation ; Dilution ; Residence Time ; Geology
    ISSN: 1040-6182
    E-ISSN: 1873-4553
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Geochimica et Cosmochimica Acta, 1998, Vol.62(18), pp.3041-3045
    Description: The {sup 4}He, {sup 40}Ar, and {sup 136}Xe content dissolved in the pore water of sedimentary rock samples was measured on samples from borehole cores near the repository for nuclear waste in Morsleben, Germany. Due to the very low permeabilities of the rock formations, conventional groundwater sampling was almost impossible. Hence, the authors developed a new sampling method for noble gases in the pore water of freshly drilled rock cores. This method provides vertical noble gas profiles in high depth resolution, even in impermeable rocks. By application of the new technique quantitative age information of groundwater and pore water have been derived. The authors find palaeowaters from the last glaciation depleted in {delta}D and {delta}{sup 18}O with a {sup 4}He age of about 55 kyr. The high saline pore solutions below are at least 6 Mio years old. This has been concluded from the profiles of radiogenic {sup 4}He and {sup 40}Ar close to diffusion in steady-state and from xenon isotopes produced by spontaneous fission of {sup 238}U in the rocks. A {sup 4}He flux of 2 {center_dot} 10{sup {minus}7} cc STP/cm{sup 2} yr is derived from the profile, which is due to local {sup 4}He production within the investigated sediments.
    Keywords: Geology
    ISSN: 0016-7037
    E-ISSN: 1872-9533
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Geochimica et Cosmochimica Acta, 2009, Vol.73(4), pp.911-922
    Description: Groundwater is an important and often exclusive water resource in arid and semi-arid regions. The aim of the present paper was to gain insight into the processes and conditions that control the deterioration of groundwater quality in the semi-arid Kalahari of Botswana. Measurements of He, He, Ne, Ne, and of C of dissolved inorganic carbon (DIC) were combined with existing isotopic and hydrochemical data to investigate groundwater from the Ntane Sandstone Aquifer, which is affected by high nitrate concentrations of non-anthropogenic origin. All groundwater samples revealed neon concentrations in excess to air-saturated water, which we attributed to the addition of excess air during recharge. Neon concentrations ranged from values close to air saturation for C DIC rich samples (up to 80.5%MC) up to values of 90% in excess to air-saturated water for lower C DIC contents (2.6–61.3%MC). A strong linear correlation of excess Ne with nitrate concentrations suggests an intimate connection between groundwater quality and the processes and conditions during groundwater recharge. Low groundwater recharge rates under present-day semi-arid conditions are associated with low amounts of excess Ne and elevated nitrate concentrations. In contrast to this, higher excess Ne values in groundwater of lower C DIC and nitrate contents indicate that the high quality groundwater end-member presumably is related to higher groundwater table fluctuations during wetter climatic conditions in the past. We attribute the decline in groundwater quality with respect to nitrate to a decreasing rate and temporal variability of groundwater recharge, and to concurrent changes in biogeochemical activities following a transition to a drier climate during the Holocene. Under such conditions, a much stronger decrease in groundwater recharge compared to the release of nitrate from soil organic matter may result in elevated nitrate concentrations in the vadose zone and groundwater. This implies a strong impact of climate change on the transport of solutes like nitrate through the vadose zone which needs to be considered in predictions of future groundwater quality.
    Keywords: Geology
    ISSN: 0016-7037
    E-ISSN: 1872-9533
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Acta hydrochimica et hydrobiologica, September 2001, Vol.29(2‐3), pp.129-138
    Description: Flooding of uranium mines causes a release of considerable amounts of uranium, radium‐226, and arsenic into rivers and aquifers. Thus treatment is necessary in some cases. In order to evaluate alternative water treatment methods for mine water a research project was carried out by means of both laboratory experiments and small‐scale field tests in abundant mines of the Ore Mountains in East Germany. At two test sites columns filled with Fe, Fe/Mn containing waste sludge, and peat were installed for the duration of one year to investigate geochemical reactions and the fixation processes of relevant radionuclides and arsenic. While Fe is changing the geochemical conditions from oxidizing to reducing milieu, peat and Fe/Mn‐sludge have a significant sorption capacity. In addition, iron hydroxides coprecipitate residual contaminants. The fixation capacity of peat was found to be exhausted within half a year. The Fe/Mn‐sludge adsorbed 60% of radium and 70% of arsenic. The best results for uranium elimination of about 96% were obtained by means of Fe In‐situ‐Behandlung von radioaktiven Bergbauwässern mit reaktiven Materialien – Ergebnisse von Labor‐ und Feldversuchen in deutschen Uranbergwerken Bei der Flutung von Bergwerken sind die Metall‐ und Radionuklidgehalte der Wässer deutlich erhöht und müssen vielfach vor dem Eintritt in die Vorfluter behandelt werden. Als Alternative zu konventionellen Wasserreinigungsverfahren wurden neben Laborversuchen über ein Jahr Feldversuche mit reaktiven Materialien in Bergwerken im sächsischen Erzgebirge zur Eliminierung der Schadstoffe aus Flutungswässern durchgeführt. Als Materialien wurden Fe, Fe/Mn‐haltiger Wasserwerksschlamm (aus der Flockungsstufe) und Torf ausgewählt. Während die Fixierung des Urans mittels Fe auf einer geochemischen Milieuwandlung und Aus‐ bzw. Mitfällung an Eisenhydroxiden basiert, wird bei den übrigen Materialien die hohe Sorptionskapazität ausgenutzt. Wie die Ergebnisse zeigen, ist Fe gut für die alternative Behandlung von Flutungswässern geeignet. Die Sorptionskapazität von Torf war nach einem halben Jahr erschöpft. Mit Hilfe der Fe/Mn‐Verbindungen wurden im Mittel 60% Radium und 70% Arsen eliminiert. Die höchste Effektivität für Uran‐Spezies zeigten Eisenspäne mit einer Eliminierungsrate von bis zu 96%.
    Keywords: Mine Water Treatment ; Mine Flooding ; Zero‐Valent Iron ; Geochemical Barrier ; Radionuclide Fixation ; Wasserbehandlung ; Grubenflutung ; Nullwertiges Eisen ; Geochemische Barriere ; Radionuklidimmobilisierung
    ISSN: 0323-4320
    E-ISSN: 1521-401X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Journal of Soils and Sediments, 2008, Vol.8(1), pp.23-33
    Description: Byline: Gerhard Strauch (1), Monika Moder (2), Rainer Wennrich (2), Karsten Osenbruck (3), Hans-Reinhard Glaser (1), Timo Schladitz (1), Claudia Muller (1), Kristin Schirmer (4), Frido Reinstorf (1), Mario Schirmer (1) Keywords: Carbamacepine; endocrine disrupters; gadolinium; indicators; stable isotopes; urban water; xenobiotics Abstract: Background, Aim and Scope Our study focuses on the indication of anthropogenic impacts on the urban surface and groundwater in large cities, demonstrated for the cities of Halle/Saale and Leipzig (Germany). For the study we selected indicator substances such as xenobiotics, trace elements, and stable isotopes which are connected to human activities in urban areas. The xenobiotics reported here are the pharmaceutical carbamacepine, the polycylic musk compounds galaxolide and tonalide, the life style product caffeine, and industrial chemicals such as bisphenol A and t-nonylphenol. The investigated xenobiotics pose largely unknown risks to human health and the aquatic ecosystem. Trace elements are represented by the rare earth element gadolinium (Gd), used as magnetic resonance imaging contrast substance. Nitrogen isotopes in dissolved nitrate characterize the origin of nitrogen compounds, mixing and reaction processes. Methodology River water was sampled along the flow path of the rivers Saale and Weisse Elster through the city of Halle/Saale, the rivers Luppe and Weisse Elster through the city of Leipzig. Separate samples were collected from the effluent of the local waste water treatment plants. Groundwater from Quaternary plain aquifers along the rivers and from different urban locations was collected at the same time. The indicators were analysed and assessed according to their sources, concentration and distribution patterns. Results and Discussion Based on the nitrogen isotopic signature, dissolved nitrate in river water of the Saale was referred mainly to two sources: the effluent of the water treatment plant and a mixture of diffusive inputs from rain water channels, sewage leakages and agriculture activities along the rivers. The Gd anomaly was recognized in surface water of both cities, particularly in the effluent of the water treatment plants, but clearly attenuated in groundwater. We measured concentrations of xenobiotics in river and sewer water between 10 and 60,000 ng L.sup.-1, and, in groundwater, one order of magnitude lower. Distinctions of xenobiotic patterns were found in river water before and after the effluent of treated waste water into the rivers. Degradation of endocrine disrupters and fragrances, but also persistence of carbamacepine were recognized as essential processes during waste water treatment. At the study site Halle/Saale, mass balances were set up for xenobiotics and water fluxes. Conclusions At both sites, we demonstrated that indicators such as xenobiotics, gadolinium, and nitrogen isotopes are suitable for assessing anthropogenic impacts on urban water. However, the behaviour of these indicators in surface and groundwater has to be considered according to the different geochemical environments. Author Affiliation: (1) Department of Hydrogeology, UFZ Helmholtz Centre for Environmental Research, Leipzig, Germany (2) Deptartment of Analytical Chemistry, UFZ Helmholtz Centre for Environmental Research, Leipzig, Germany (3) Department of Isotope Hydrology, UFZ Helmholtz Centre for Environmental Research, Theodor-Lieser-Str. 4, 06120, Halle, Germany (4) Department of Cell Toxicology, UFZ Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318, Leipzig, Germany Article History: Registration Date: 03/03/2007 Received Date: 06/11/2006 Accepted Date: 11/06/2007 Online Date: 12/06/2007
    Keywords: Carbamacepine ; endocrine disrupters ; gadolinium ; indicators ; stable isotopes ; urban water ; xenobiotics
    ISSN: 1439-0108
    E-ISSN: 1614-7480
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages