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Author Musy, S.; Meyzonnat, G.; Barbecot, F.; Hunkeler, D.; Sültenfuss, J.; Solomon, D.K.; Purtschert, R. url  openurl
  Title In-situ sampling for krypton-85 groundwater dating Type Journal Article
  Year 2021 Publication Journal of Hydrology X Abbreviated Journal  
  Volume 11 Issue Pages 100075  
  Keywords Noble gases, Tracers, Groundwater, Dating, Sampling Methodology  
  Abstract Krypton-85 and other radioactive noble gases are widely used for groundwater dating purposes. 85Kr analysis require large volumes of water to reach the analytical requirements. Conventionally, this water is pumped to the surface to be degassed with a gas extraction system. The large pumping rate may disturb the natural flow field and requires substantial field logistics. Hence, we propose a new in-situ degassing method, in which membrane contactors are used to degas the groundwater directly in the well and gas is collected at the surface. This way, field work is facilitated, groundwater system disturbance is minimized, and the gas sample is collected at a specific depth. We demonstrate the tightness of the system regarding atmospheric air contamination for a collection times of 24 h, which is sufficient for both low-level counting and laser-based counting methods for 85Kr. The minimal borehole diameter is 7.5 cm for the prototype presented in this research but can easily be reduced to smaller diameters. In a case study, we compare the results obtained with the new passive method with those from a conventional packer setup sampling. Additionally, 3H/3He samples were collected for both sampling regimes and the dating results were compared with those from 85Kr. A good agreement between tracer ages is demonstrated and the age stratigraphy is consistent with the expected age distribution for a porous unconfined aquifer. In addition, our study emphasizes the differences between the age information sampled with various methods. In conclusion, we demonstrate that the new in situ quasi-passive method provides a more representative age stratigraphy with depth in most cases.  
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  Series Volume Series Issue Edition  
  ISSN 2589-9155 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ Musy2021100075 Serial 215  
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Author Kharazi, P.; khazaeli, E.A.; Heshmatpour, A. url  openurl
  Title Delineation of suitable sites for groundwater dams in the semi-arid environment in the northeast of Iran using GIS-based decision-making method Type Journal Article
  Year 2021 Publication Groundwater for Sustainable Development Abbreviated Journal  
  Volume 15 Issue Pages 100657  
  Keywords Subsurface dam, Hybrid decision-making method, Geographic information system, Analytical hierarchy process, EDAS, TOPSIS1  
  Abstract Competing commercial demands on water resources need to be balanced as the world’s population rises. Generally, groundwater is raised by subsurface dams. In this paper, the geographic information system (GIS) software and a decision-making method were applied. As the first step, the limitations that affect the establishment of the subsurface dam were identified using eliminating criteria by the Boolean logic. Regarding the second step, the most appropriate axis was determined for subsurface dam construction in each of the limits. The analytical hierarchy process (AHP) was applied according to the evaluation criteria in this study. The aim of using AHP was to weigh and prioritize the criteria of the groundwater dam for recognizing appropriate sites. Among various places and regarding the subsurface dam construction, AHP was conducted using a hierarchy process for finding the most suitable sites in the third stage of the decision-making method. Finally, among the ten appropriate sites, cross comparison was drawn by using Decision Expert (DEX), Evaluation based on Distance from Average Solution (EDAS), and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Compared together (as a process of decision-making), DEX, TOPSIS, and EDAS methods assisted in ranking the most appropriate sites in the final step of subsurface dam pre-selection. A and C axes obtained scores between 1 and 2, among 10 axes according to the numerically ranked locations. Regarding the water shortage issue and better management of the underground water at certain levels, the findings of this study could be useful for the residents of Kajbid-Balaqly Watershed in the dry season. Further, water managers can use the above-mentioned methods for their decisions regarding the proper subsurface dam establishment.  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2352-801x ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ Kharazi2021100657 Serial 250  
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Author Zeng, S.; Shen, Y.; Sun, B.; Zhang, N.; Zhang, S.; Feng, S. url  openurl
  Title Pore structure evolution characteristics of sandstone uranium ore during acid leaching Type Journal Article
  Year 2021 Publication Nuclear Engineering and Technology Abbreviated Journal  
  Volume 53 Issue 12 Pages 4033-4041  
  Keywords Acid method, In situ leaching, Nuclear magnetic resonance, Pore characteristic, Sandstone uranium ore  
  Abstract To better understand the permeability of uranium sandstone, improve the leaching rate of uranium, and explore the change law of pore structure characteristics and blocking mechanism during leaching, we systematically analyzed the microstructure of acid-leaching uranium sandstone. We investigated the variable rules of pore structure characteristics based on nuclear magnetic resonance (NMR). The results showed the following: (1) The uranium concentration change followed the exponential law during uranium deposits acid leaching. After 24 h, the uranium leaching rate reached 50%. The uranium leaching slowed gradually over the next 4 days. (2) Combined with the regularity of porosity variation, Stages I and II included chemical plugging controlled by surface reaction. Stage I was the major completion phase of uranium displacement with saturation precipitation of calcium sulfate. Stage II mainly precipitated iron (III) oxide-hydroxide and aluminum hydroxide. Stage III involved physical clogging controlled by diffusion. (3) In the three stages of leaching, the permeability of the leaching solution changed with the pore structure, which first decreased, then increased, and then decreased.  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1738-5733 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ zeng_pore_2021 Serial 199  
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Author Mathuthu, M.; Uushona, V.; Indongo, V. url  openurl
  Title Radiological safety of groundwater around a uranium mine in Namibia Type Journal Article
  Year 2021 Publication Physics and Chemistry of the Earth, Parts A/B/C Abbreviated Journal  
  Volume 122 Issue Pages 102915  
  Keywords Groundwater, ICP-MS, Radiological hazard, Uranium mining  
  Abstract Uranium mining activities produce the main element used in nuclear energy production. However, it can also negatively affect the environment including groundwater by release of residues or effluent containing radioactive elements. The study investigated the concentration and radiological hazard of uranium in groundwater and seepage water from the tailings of a uranium mine in Namibia. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to assess the concentration of uranium in the groundwater and seepage water and the radiological hazards were determined. The radiological hazard indices Radium equivalent activity (Raeq), Absorbed dose (D), Annual Effective Dose equivalent (AEDE), External hazard index (Hex) and Internal hazard index (Hin) were determined and compared to limits recommended by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The calculated average value of D and Hin of groundwater is 108.11nGyh−1 and 1.26, respectively and are above the UNSCEAR values (55 nGyh−1 and 1). Further, the average values of Raeq, AEDE and Hex were below the recommended values. The isotopic ratio of uranium radionuclides in groundwater indicates that the uranium in the sampled groundwater is below 1 suggesting it is not natural uranium present but a possible contamination from the mine seepage. The radiological hazard parameters of the seepage water were above the recommended values and thus pose a radiation risk to human and environment.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1474-7065 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ mathuthu_radiological_2021 Serial 160  
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Author Lapworth, D.J.; Brauns, B.; Chattopadhyay, S.; Gooddy, D.C.; Loveless, S.E.; MacDonald, A.M.; McKenzie, A.A.; Muddu, S.; Nara, S.N.V. url  openurl
  Title Elevated uranium in drinking water sources in basement aquifers of southern India Type Journal Article
  Year 2021 Publication Applied Geochemistry Abbreviated Journal  
  Volume 133 Issue Pages 105092  
  Keywords Anthropogenic, Drinking waters, Geogenic, India, Speciation, Uranium  
  Abstract Groundwater resources in the crystalline basement complex of India are crucial for supplying drinking water in both rural and urban settings. Groundwater depletion is recognised as a challenge across parts of India due to over-abstraction, but groundwater quality constraints are perhaps even more widespread and often overlooked at the local scale. Uranium contamination in basement aquifers has been reported in many parts of India, locally exceeding WHO drinking water guideline values of 30 μg/L and posing a potential health risk. In this study 130 water samples were collected across three crystalline basement catchments to assess hydrochemical, geological and anthropogenic controls on uranium mobility and occurrence in drinking water sources. Groundwaters with uranium concentrations exceeding 30 μg/L were found in all three study catchments (30% of samples overall), with concentrations up to 589 μg/L detected. There appears to be a geological control on the occurrence of uranium in groundwater with the granitic gneiss of the Halli and Bengaluru study areas having higher mean uranium concentrations (51 and 68 μg/L respectively) compared to the sheared gneiss of the Berambadi catchment (6.4 μg/L). Uranium – nitrate relationships indicate that fertiliser sources are not a major control on uranium occurrence in these case studies which include two catchments with a long legacy of intense agricultural land use. Geochemical modelling confirmed uranium speciation was dominated by uranyl carbonate species, particularly ternary complexes with calcium, consistent with uranium mobility being affected by redox controls and the presence of carbonates. Urban leakage in Bengaluru led to low pH and low bicarbonate groundwater hydrochemistry, reducing uranium mobility and altering uranium speciation. Since the majority of inhabitants in Karnataka depend on groundwater abstraction from basement aquifers for drinking water and domestic use, exposure to elevated uranium is a public health concern. Improved monitoring, understanding and treatment of high uranium drinking water sources in this region is essential to safeguard public health.  
  Address  
  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0883-2927 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ lapworth_elevated_2021 Serial 147  
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Author Heine, F.; Einsiedl, F. url  openurl
  Title Groundwater dating with dissolved organic radiocarbon: A promising approach in carbonate aquifers Type Journal Article
  Year 2021 Publication Applied Geochemistry Abbreviated Journal  
  Volume 125 Issue Pages 104827  
  Keywords C groundwater dating, deep carbonate aquifer, DOC, SPE-PPL  
  Abstract A complete hydrogeological understanding of the deep Upper Jurassic carbonate aquifer in the South German Molasse Basin is essential for the future development of this important drinking water resource and geothermally used system. Water chemistry data, δ13CDIC, 14C of the dissolved inorganic carbon (14CDIC) and stable water isotope (δ18O and δD) measurements have been used to evaluate a promising groundwater dating approach with 14C of dissolved organic carbon (14CDOC). The pre-concentration of dissolved organic matter (DOM) was performed by the easy applicable solid phase extraction (SPE) with a styrene-divinylbenzene copolymer sorbent (PPL). Based on the sampling campaign of seven groundwater wells conducted between 2017 and 2019, it was shown that the groundwater is mainly of Ca–HCO3 type with some evidence of ion exchange between Ca2+ and Na+ at two of the investigated wells. The δD values ranged from −89.4‰ to −70.9‰ while δ18O values varied between −12.5‰ and −9.8‰. The obtained stable water isotope signatures indicated that the groundwater is of meteoric origin and was recharged during warm climate (Holocene), intermediate climate and cold climate (Pleistocene) infiltration conditions. The measured 14CDOC activities varied from 5.7 pmC to 51.1 pmC and the calculated piston-flow water ages (ORAs) ranged from 4200 years to 25,248 years using an initial 14C0DOC of 85 pmC. The calculated ORAs showed a very good correlation to the infiltration temperature-sensitive δ18O values which were affirmed with noble gas infiltration temperatures for two wells after Weise et al. (1991) and were also in good accordance with the atmospheric temperature record of the northern hemisphere from Dokken et al. (2015). The results reflect a consistent hydrogeological picture of the carbonate aquifer, which also supports the applicability of the SPE-PPL method for 14CDOC dating in groundwater with a low DOC content (<1 mg/l). In contrast, 14CDIC activities of 1.4 pmC to 21.3 pmC led to geochemically corrected piston-flow ages between 8057 years and >30,000 years and generally to an overestimation of the apparent water ages. This study gives insights into the promising approach of 14CDOC groundwater dating in carbonate aquifers with low DOC contents and allows future sustainable groundwater resource management of the investigated aquifer system.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0883-2927 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ Heine2021104827 Serial 216  
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Author Jing, M.; Kumar, R.; Attinger, S.; Li, Q.; Lu, C.; Heße, F. url  openurl
  Title Assessing the contribution of groundwater to catchment travel time distributions through integrating conceptual flux tracking with explicit Lagrangian particle tracking Type Journal Article
  Year 2021 Publication Advances in Water Resources Abbreviated Journal  
  Volume 149 Issue Pages 103849  
  Keywords Travel time distribution, Flux tracking, Particle tracking, Coupled model, Predictive uncertainty  
  Abstract Travel time distributions (TTDs) provide an effective way to describe the transport and mixing processes of water parcels in a subsurface hydrological system. A major challenge in characterizing catchment TTD is quantifying the travel times in deep groundwater and its contribution to the streamflow TTD. Here, we develop and test a novel modeling framework for an integrated assessment of catchment scale TTDs through explicit representation of 3D-groundwater dynamics. The proposed framework is based on the linkage between a flux tracking scheme with the surface hydrologic model (mHM) for the soil-water compartment and a particle tracking scheme with the 3D-groundwater model OpenGeoSys (OGS) for the groundwater compartment. This linkage provides us with the ability to simulate the spatial and temporal dynamics of TTDs in these different hydrological compartments from grid scale to regional scale. We apply this framework in the Nägelstedt catchment in central Germany. Simulation results reveal that both shape and scale of grid-scale groundwater TTDs are spatially heterogeneous, which are strongly dependent on the topography and aquifer structure. The component-wise analysis of catchment TTD shows a time-dependent sensitivity of transport processes in soil zone and groundwater to driving meteorological forcing. Catchment TTD exhibits a power-law shape and fractal behavior. The predictive uncertainty in catchment mean travel time is dominated by the uncertainty in the deep groundwater rather than that in the soil zone. Catchment mean travel time is severely biased by a marginal error in groundwater characterization. Accordingly, we recommend to use multiple summary statistics to minimize the predictive uncertainty introduced by the tailing behavior of catchment TTD.  
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  Series Volume Series Issue Edition  
  ISSN 0309-1708 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ Jing2021103849 Serial 220  
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Author Milena-Pérez, A.; Piñero-García, F.; Benavente, J.; Expósito-Suárez, V.M.; Vacas-Arquero, P.; Ferro-García, M.A. url  openurl
  Title Uranium content and uranium isotopic disequilibria as a tool to identify hydrogeochemical processes Type Journal Article
  Year 2021 Publication Journal of Environmental Radioactivity Abbreviated Journal  
  Volume 227 Issue Pages 106503  
  Keywords 234U/238U, Betic cordillera, Groundwater, Hydrogeochemistry, Uranium natural isotopes  
  Abstract This paper studies the uranium content and uranium isotopic disequilibria as a tool to identify hydrogeochemical processes from 52 groundwater samples in the province of Granada (Betic Cordillera, southeastern Spain). According to the geological complexity of the zone, three groups of samples have been considered. In Group 1 (thermal waters; longest residence time), the average uranium content was 2.63 ± 0.16 μg/L, and 234U/238U activity ratios (AR) were the highest of all samples, averaging 1.92 ± 0.30. In Group 2 (mainly springs from carbonate aquifers; intermediate residence time), dissolved uranium presented an average value of 1.34 ± 0.13 μg/L, while AR average value was 1.38 ± 0.25. Group 3 comes from pumping wells in a highly anthropized alluvial aquifer. In this group, where the residence time of the groundwater is the shortest of the three, average uranium content was 5.28 ± 0.26 μg/L, and average AR is the lowest (1.17 ± 0.12). In addition, the high dissolved uranium value and the low AR brought to light the contribution of fertilizers (Group 3). In the three groups, 235U/238U activity ratios were similar to the natural value of 0.046. Therefore, 235U detected in the samples comes from natural sources. This study is completed with the determination of major ions and physicochemical parameters in the groundwater samples and the statistical analysis of the data by using the Principal Component Analysis. This calculation indicates the correlation between uranium isotopes and bicarbonate and nitrate anions.  
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  Series Volume Series Issue Edition  
  ISSN 0265-931x ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ milena-perez_uranium_2021 Serial 112  
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Author Rallakis, D.; Michels, R.; Cathelineau, M.; Parize, O.; Brouand, M. url  openurl
  Title Conditions for uranium biomineralization during the formation of the Zoovch Ovoo roll-front-type uranium deposit in East Gobi Basin, Mongolia Type Journal Article
  Year 2021 Publication Ore Geology Reviews Abbreviated Journal  
  Volume 138 Issue Pages 104351  
  Keywords Bioreduction, East Gobi Basin, Mongolia, Organic matter, Roll-front, Sulfur isotopes, Uranium  
  Abstract The Zoovch Ovoo uranium roll-front-type deposit is hosted in the Sainshand Formation, a Late Cretaceous siliciclastic reservoir, which constitutes the upper part of the post-rift infilling of the Mesozoic East Gobi Basin in SE Mongolia. The Sainshand Formation consists of unconsolidated medium-grained sand, silt and clay intervals deposited in fluvial-lacustrine settings. The uranium deposit is confined within a 60–80 m thick siliciclastic sequence inside aquifer-driven systems. The overall system experienced shallow burial and was never subjected to temperatures higher than 40 °C. This study proposes a comprehensive metallogenic model for this uranium deposit. Sedimentological and mineralogical observations from drill core samples to the microscopic scale (optical and Scanning Electron Microscopy) together with in situ geochemistry of late-formed phases (Laser Ablation–Inductively Coupled Plasma Mass Spectrometry, Electron Probe Microanalysis, Fourier Transform–Infrared Spectroscopy) were considered for the reconstruction of the main stages of U trapping. In the mineralized zone, the uranium ore is expressed as Ca–enriched uraninite (UO2) and less commonly as Ca–enriched phospho-coffinite (U, P)SiO4. Trapping mechanisms include i) complexation (i.e. uranyl-carboxyl complexes), ii) adsorption on organic or clay particles) and iii) reduction by pyrite and by bacterial activity to amorphous uraninite. In all cases, the organic matter plays either the role of trap for uranium or nutrient for bacteria that can trap uranium through their metabolism. The shallow burial diagenesis conditions do not allow direct reduction of U(VI) by organic carbon. The δ34S values of the iron disulfide are very diverse, fluctuating in extreme cases between −50 to + 50‰, with an average δ34S value for framboidal pyrite at 2‰, and −20‰ for euhedral pyrite. The positive and negative values reflect close versus open fractionation systems, while bacterial sulphate reduction (BSR) is active during the whole diagenetic history of the deposit as an essential source of reduced sulfur. Therefore, using detrital organic matter as a carbon source, microorganisms play a significant role in uranium trapping, either as a direct reducing agent for uranium or pyrite formation, which will trap uranium through redox driven epigenetic processes.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-1368 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ rallakis_conditions_2021 Serial 176  
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Author Pontér, S.; Rodushkin, I.; Engström, E.; Rodushkina, K.; Paulukat, C.; Peinerud, E.; Widerlund, A. url  openurl
  Title Early diagenesis of anthropogenic uranium in lakes receiving deep groundwater from the Kiruna mine, northern Sweden Type Journal Article
  Year 2021 Publication Science of The Total Environment Abbreviated Journal  
  Volume 793 Issue Pages 148441  
  Keywords Isotope ratios, Mine water, Sediments, Uranium  
  Abstract The uranium (U) concentrations and isotopic composition of waters and sediment cores were used to investigate the transport and accumulation of U in a water system (tailings pond, two lakes, and the Kalix River) receiving mine waters from the Kiruna mine. Concentrations of dissolved U decrease two orders of magnitude between the inflow of mine waters and in the Kalix River, while the concentration of the element bound to particulate matter increases, most likely due to sorption on iron‑manganese hydroxides and organic matter. The vertical distribution of U in the water column differs between two polluted lakes with a potential indication of dissolved U supply from sediment’s pore waters at anoxic conditions. Since the beginning of exposure in the 1950s, U concentrations in lake sediments have increased \textgreater20-fold, reaching concentrations above 50 μg g-1. The distribution of anthropogenic U between the lakes does not follow the distribution of other mine water contaminants, with a higher relative proportion of U accumulating in the sediments of the second lake. Concentrations of redox-sensitive elements in the sediment core as well as Fe isotopic composition were used to re-construct past redox-conditions potentially controlling early diagenesis of U in surface sediments. Two analytical techniques (ICP-SFMS and MC-ICP-MS) were used for the determination of U isotopic composition, providing an extra dimension in the understanding of processes in the system. The (234 U)/(238 U) activity ratio (AR) is rather uniform in the tailings pond but varies considerably in water and lake sediments providing a potential tracer for U transport from the Kiruna mine through the water system, and U immobilization in sediments. The U mass balance in the Rakkurijoki system as well as the amount of anthropogenic U accumulated in lake sediments were evaluated, indicating the immobilization in the two lakes of 170 kg and 285 kg U, respectively.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0048-9697 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ ponter_early_2021 Serial 154  
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