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EN
For the present study, geochemical ages were derived from radiocarbon and radiokrypton age calibration with ground-water chemical contents (Na+, K+, Mg2+, Ca2+, Cl−, SO42−, HCO3−). Geochemical ages may fill the dating gap (40–150 ka) between the isotope techniques mentioned. A case study of groundwater in the Baltic Artesian Basin has involved geochemical age calibration, data filtering (such as regional subdivision of the basin for more accurate results) and geochemical dating of groundwater of unknown age. Various approaches to interpretations of geochemical age results could be used. Bicarbonate and sulphate are sensitive to the hydrochemical environment and should be omitted from geochemical age calculations. Modern fresh groundwater samples should also be excluded from calibration in order to obtain more reliable trend lines. Calcium-sodium cation exchange occurs in deep aquifers and may be used for geo- chemical age determination of fossil groundwater.
PL
Na temat warunków hydrogeologicznych niecki łódzkiej występują odmienne poglądy, szczególnie dotyczące warunków zasilania tego systemu wodonośnego w rejonie aglomeracji łódzkiej. Badania zmienności stężeń znaczników środowiskowych migrujących do systemu wodonośnego z „góry” i z „dołu” pozwoliły na wprowadzenie do dyskusji nowych wyników i weryfikację dotychczasowych koncepcji warunków krążenia wód w tej strukturze wodonośnej. Wiek wód podziemnych w poziomie K2 kształtuje się w zakresie 4600−12 100 lat, w zależności od głębokości opróbowanej studni i jej położenia w granicach strukturalnych niecki. Skład izotopowy wód w tym poziomie jest najprawdopodobniej warunkowany procesami wymiany izotopowej, dyfuzji i napływem wód ze stref o utrudnionym przepływie. Wiek wód w poziomie K1 zmienia się w zakresie ok. 300−2600 lat, w zależności od odległości od stref zasilania. Uzyskane rezultaty wskazują, że w obrębie badanego systemu wodonośnego występują zróżnicowane warunki krążenia w poziomach wodonośnych K1 i K2. Pomiary stężeń CFC, SF6 i gazów szlachetnych wnoszą istotne informacje, dotyczące systemu krążenia wód, w tym lokalizacji stref zasilania, nawet jako surowe dane – niezależnie od wykorzystania ich do określenia wieku wód.
EN
There are different views on the hydrogeological conditions of the Łódź Basin, especially regarding the conditions of recharging this structure within the Łódź agglomeration area. Studies on the variability of concentrations of environmental tracers migrating to the aquifer from both the “top” and the “bottom” allowed introducing new results into the discussion and verification of the existing concepts of groundwater circulation conditions in this aquifer system. Residence time of groundwater in the K2 aquifer is in the range of 4,600−12,100 years, depending on the depth of the tested well and its position within the structural limits of the basin. The isotopic composition of water in this aquifer is probably conditioned by the isotopic exchange, diffusion and inflow of groundwater from the low-permeability flow zones. The ages of groundwater in the K1 aquifer vary between ca. 300 and 2,600 years depending on the distance from the recharge area. The obtained results indicate that there are various circulating conditions in the analyzed aquifers of the Upper and Lower Cretaceous. The measurements of concentrations of CFC, SF6 and noble gases bring important information about the groundwater circulation system (including the location of recharge areas) even as raw data – regardless of their use to determine the ages of groundwater.
EN
The paper presents the method of chromatographic determination of noble gases concentrations (He, Ne and Ar) in groundwater. He concentration in groundwater is helpful in groundwater dating over a wide range of time. Ne and Ar concentrations are used to calculate excess air and recharge temperature of groundwater. Sulphide waters occurring in Cenomanian sediments in the southern part of the Miechów Trough in Busko-Zdrój, Krzyż and Kazimierza Wielka areas are the subject of research. The results of the noble gases concentrations measurements for boreholes: Busko C-1, Cudzynowice GT-1 and Wełecz S-6 are presented as well as the methodology of calculating concentrations of these gases and groundwater ages.
EN
Groundwater age plays an important role in both development and management of groundwater resources. This is particularly true for groundwater systems being exploitedfor drinking water purposes and subject to anthropogenic stress. Environmental isotopes play a vital role in quantifying time scales of groundwater flow, ranging from fraction of a year to millions of years. Over the past several decades a large number of groundwater age indicators have been proposed. Apart of radioactive isotopes, also stable isotopes of water, isotopes of noble gases and anthropogenic trace substances present in the atmosphere have been usedfor this purpose. This work is focusing on methodological aspects of groundwater age determinations using tritium, radiocarbon and stable isotope composition of water. The discussion is based on a rich material available after several decades of application of environmental isotope techniques in groundwater studies in Poland.
EN
We present the results of isotope measurements (δ18O, δ D, δ13CDIC and 14C) and chemical analyses (TDS, TOC, HCO3–, SO42–, Cl–, NO3–, NH4+, Ca2+, Mg2+ Na+ and K+) conducted on groundwater samples collected from deep Cenozoic aquifers. These aquifers are the basic source of drinking water at numerous localities within the study area in northern Poland. Most of the δ18O determinations are characterised by low variability (i.e., > 70 per cent of δ18O are between –9.5‰ and –9.2‰). In most cases tritium activity was not detected or its content slightly exceeded the uncertainty of measurement (from ±0.3 T.U. to ± 0.5 T.U.). On average, 14C activity is twice higher than that under similar conditions and in hydrogeological systems. The δ13CDIC values fall within the –13.6‰ to –12.8‰ range. A slight variability is observed when considering all isotope and chemical data within the study area and under these hydrogeological conditions. In general, the results of isotope and chemical analyses seem to be homogeneous, indicating the presence of closely similar groundwaters in the system, irrespective of geological formation. It is likely that there is a significant hydraulic connection between shallow and deep aquifers in the Gwda catchment, which indicates the potential for seepage of pollutants from shallow Pleistocene to deep Miocene aquifers. This can endanger the latter by e.g., high concentrations of NO3–, SO42– and Cl– ions from shallow aquifers within the Gwda catchment.
EN
In this study the method for evaluating resistance hydrogeological systems to anthropogenic pollution using environmental tracers is described. Resistance of groundwater systems to anthropogenic pollution is correlated with the age of water, which can be determined by means of environmental tracers. The paper presents modified chromatographic measurement system which allow for the determination of CFC-11, CFC-12, SF6, Ne, Ar and He. Developed chromatographic system can be used to dating young groundwaters, and the helium method allows for the determination of groundwater age in the range from Holocene to the last interglacial. The developed measurement system of argon and neon in water allows to determine recharge temperature and the amount of "excess air" in groundwater. During the work implementation authors took part in a research project organized by the Université Paris-Sud and Université Rennes, France: Gdat1 intercomparison exercice. This exercise aimed to sampling groundwater from boreholes from the area of Paris (along with 31 laboratories from 14 countries) and test, upon them, developed at IFJ PAN analytical methods measuring CFCs, SF6 and noble gases in groundwater
PL
W artykule zaprezentowano chromatograficzną metodę jednoczesnego pomiaru stężenia helu, neonu oraz argonu w wodach podziemnych z pojedynczej próbki wody. Próbki wody podziemnej są pobierane do stalowych naczyń o pojemności 2900 cm3. Gazy są ekstrahowane z wody metodą fazy nadpowierzchniowej (HS). Hel, neon oraz argon są analizowane na dwóch chromatografach gazowych wyposażonych w kolumny kapilarne i pakowane oraz trzy detektory cieplno-przewodnościowe (TCD). Stężenie helu w wodzie podziemnej może być dobrym znacznikiem do datowania wód podziemnych. Poprawne stosowanie znaczników środowiskowych w hydrogeologii w celu datowania wymaga znajomości temperatury zasilania systemu i tzw. „nadmiaru powietrza”. Znajomość nadmiaru powietrza pozwala na konieczną korektę mierzonego stężenia helu w wodzie. Obydwa parametry można wyznaczyć przez pomiar stężenia argonu i neonu w wodzie podziemnej. Opracowana metoda chromatograficzna była zastosowana do datowania wód podziemnych z rejonów między innymi Niecki Podhalańskiej, Krakowa oraz Żarnowca.
EN
In this paper the authors present a chromatographic method for simultaneous analysis of helium, neon and argon in groundwater from one water sample. Water samples are taken to the stainless steel vessels with a capacity of 2,900 cm3. Gases are extracted from water by headspace method (HS). Helium, neon and argon are analyzed on two gas chromatographs equipped with capillary and packed columns and three thermo-conductive detectors (TCD). The concentration of helium in groundwater may be a good environmental tracer for groundwater dating. Proper use of environmental tracers in hydrogeology for dating purpose, requires the knowledge of recharge temperature of the system and the so-called “Excess air”. “Excess air” allows for the necessary correction of measured concentration of helium in water. Both parameters can be determined by measuring the concentration of argon and neon in groundwater. Developed chromatographic method was applied to groundwater dating from areas of Podhalańska Basin, Kraków and Żarnowiec.
EN
Comprehensive investigations of groundwater were performed in a sedimentary aquifer of Permo-Carboniferous, Intra-Sudetic Synclinorium, in SWPoland. The investigation included aqueous chemical and isotopic composition, chemistry of mineral phases, geochemical modelling, and tritium and radiocarbon groundwater dating. Chemical diversity in the groundwater system is created by the mixing of modern fresh water and older sulphate water with higher dissolved solids. The system is treated as a system of flows of two end-member water types. Geochemical modelling is used for: (1) explaining the origin of the chemistry of both water components, (2) quantifying the groundwater mixing, (3) correcting the radiocarbon age of the groundwater for the effects of chemical water-rock interactions, and (4) calculating reaction rates. Study of stable (C, S, O, H) and unstable ([^3H], [^14]C) isotopes allowed the inverse mass balance geochemical models to be verified and specified, and the groundwater to be dated. The chemistry of the modern, tritium-bearing, fresh water is a result of dissolution of limestones, dolomites and gypsum. The mean tritium-age of this water, based on the lumped-parameter approach, varies between 10 and 200 years. The sulphate mineral water owes its chemistry to the process of dedolomitization driven by gypsum dissolution. Its radiocarbon age is about 5.9 ka BP, i.e., during theMid-Holocene Climatic Optimum. Rates of chemical reactions responsible for the formation of sulphate type water are estimated to be: dissolution of gypsum (2.85 [mi]mol/L/year) and dolomite (0.21 [mi]mol/L/year), calcite precipitation (0.20 [mi]mol/L/year), organic matter decomposition (0.08 [mi]mol/L/year).
EN
Ne, Ar, CFC-11, CFC-12 and SF6 are widely used as markers in the studies of ground-water systems. Usually, their analysis involves a use of two or three separate instrumental methods and separate sets of water samples. In this work a gas chromatographic method for simultaneous determination of Ne. Ar, SF6, CFC-11 and CFC-12 in one groundwater sample has been presented. The analytes of interest were extracted from the water sample using the headspace method and analyzed employing a system consisting of four chromatographic channels. Limits of detection for the measured tracers were: 0.06 fmol L-1 (0.0081 pg kg-1) for SF6,15 fmol L-1 (2.1 pg kgpg kg-1) for CFC-11, 10 fmol L-1 (1.23 pgkg-1) for CFC-12,0.84 nmol L-1 ( 1.9x 10 cm3 STP cm-3) for Ne, and 0.15 &mumol L-1 (3.1 x 10-6 cm-3 STP cm-3) for Ar.
PL
Ne, Ar. CFC-11, CFC-12 i SSF6 sąpowszechnie stosowane jako znaczniki w badaniach wód podziemnych. Pomiar stężenia tych związków przeprowadza się zazwyczaj dwiema lub trzema różnymi metodami analitycznymi z wykorzystaniem oddzielnych zestawów próbek wód. W niniejszej pracy przedstawiono opis chromatograficznej metody jednoczesnego oznaczania Ne, Ar, SF6 oraz freonów F-11 i F-12 w pojedynczej próbce wód podziemnych.Poziomy wykrywalności mierzonych związków wynoszą 0,06 fmol L-1 (0.0081 pg kg w przypadku SF6; 15 fmol L-1 (2,1 fg cm-3 w przypadku F-ll; 10 fmol L<-1 (1,23 pg kg-1 w przypadku F-12; 0,84 nmol L-1 (l ,9 x 10-8 cm3 STP cm-') w przypadku Ne i 0,15 μmol L-1 (3,1 x 10-6 cm3 STP cm-3) w przypadku Ar.
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