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Author (down) Pastukhov, A.M.; Rychkov, V.N.; Smirnov, A.L.; Skripchenko, S.Y.; Poponin, N.A. url  openurl
  Title Purification of in situ leaching solution for uranium mining by removing solids from suspension Type Journal Article
  Year 2014 Publication Minerals Engineering Abbreviated Journal  
  Volume 55 Issue Pages 1-4  
  Keywords Bag filter, Firm particles, In situ leaching mining, Injection wells, Intake capacity, Purification  
  Abstract This study investigated the process of in situ leaching (ISL) method of uranium mining, and the removal of solid particles from the leaching solution. Investigations were carried out for 4months. The content of firm suspensions in the productive solutions arriving from the well field was up to standard of 3–5mg/l. After keeping in a settler of productive solutions within one hour concentration of suspensions decreases to 2–2.5mg/l. To increase the life of the wells requires more fine purification of the ISL solutions. The best results can be obtained but using filtration. Bag filters were used in experiments carried out at the extraction site. All samples of polypropylene bag filter was produced by the Tamfelt Corporation. The best results were obtained for fabrics S-51M03-L2K4 (pore size 3μm). After three month of trials following indicators of wells work were fixed: on the trial cell decrease in intake capacity did not occur; on the other cells of well field injectability of holes for the same period of time decreased for 15–40%. The results illustrated the high efficiency of this method, which allows injection wells to reach a constant intake capacity, making it possible for technological cells to achieve a constant productivity and balance. Purification of solutions allows to reduce acidulation term of new technological cells from 3–4 to 1.5–2months.  
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  Series Volume Series Issue Edition  
  ISSN 0892-6875 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ pastukhov_purification_2014 Serial 204  
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Author (down) Paradis, C.J.; Hoss, K.N.; Meurer, C.E.; Hatami, J.L.; Dangelmayr, M.A.; Tigar, A.D.; Johnson, R.H. url  openurl
  Title Elucidating mobilization mechanisms of uranium during recharge of river water to contaminated groundwater Type Journal Article
  Year 2022 Publication Journal of Contaminant Hydrology Abbreviated Journal  
  Volume 251 Issue Pages 104076  
  Keywords Desorption, Dissolution, Groundwater, Surface water, Tracer, Uranium  
  Abstract The recharge of stream water below the baseflow water table can mobilize groundwater contaminants, particularly redox-sensitive and sorptive metals such as uranium. However, in-situ tracer experiments that simulate the recharge of stream water to uranium-contaminated groundwater are lacking, thus limiting the understanding of the potential mechanisms that control the mobility of uranium at the field scale. In this study, a field tracer test was conducted by injecting 100 gal (379 l) of oxic river water into a nearby suboxic and uranium-contaminated aquifer. The traced river water was monitored for 18 days in the single injection well and in the twelve surrounding observation wells. Mobilization of uranium from the solid to the aqueous phase was not observed during the tracer test despite its pre-test presence being confirmed on the aquifer sediments from lab-based acid leaching. However, strong evidence of oxidative immobilization of iron and manganese was observed during the tracer test and suggested that immobile uranium was likely in its oxidized state as U(VI) on the aquifer sediments; these observations ruled out oxidation of U(IV) to U(VI) as a potential mobilization mechanism. Therefore, desorption of U(VI) appeared to be the predominant potential mobilization mechanism, yet it was clearly not solely dependent on concentration as evident when considering that uranium-poor river water (\textless0.015 mg/L) was recharged to uranium-rich groundwater (≈1 mg/L). It was possible that uranium desorption was limited by the relatively higher pH and lower alkalinity of the river water as compared to the groundwater; both factors favor immobilization. However, it was likely that the immobile uranium was associated with a mineral phase, as opposed to a sorbed phase, thus desorption may not have been possible. The results of this field tracer study successfully ruled out two common mobilization mechanisms of uranium: (1) oxidative dissolution and (2) concentration-dependent desorption and ruled in the importance of advection, dispersion, and the mineral phase of uranium.  
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  ISSN 0169-7722 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ paradis_elucidating_2022 Serial 135  
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Author (down) Orloff, K.G.; Mistry, K.; Charp, P.; Metcalf, S.; Marino, R.; Shelly, T.; Melaro, E.; Donohoe, A.M.; Jones, R.L. url  openurl
  Title Human exposure to uranium in groundwater Type Journal Article
  Year 2004 Publication Environmental Research Abbreviated Journal  
  Volume 94 Issue 3 Pages 319-326  
  Keywords Groundwater, Human exposure, Uranium, Urine  
  Abstract High concentrations of uranium (mean=620μg/L) were detected in water samples collected from private wells in a residential community. Based on isotopic analyses, the source of the uranium contamination appeared to be from naturally occurring geological deposits. In homes where well water concentrations of uranium exceeded the drinking water standard, the residents were advised to use an alternate water source for potable purposes. Several months after the residents had stopped drinking the water, urine samples were collected and tested for uranium. Elevated concentrations of uranium (mean=0.40μg/g creatinine) were detected in urine samples, and 85 percent of the urine uranium concentrations exceeded the 95th percentile concentration of a national reference population. Urine uranium concentrations were positively correlated with water uranium concentrations, but not with the participants’ ages or how long they had been drinking the water. Six months later, a second urine sample was collected and tested for uranium. Urine uranium concentrations decreased in most (63 percent) of the people. In those people with the highest initial urine uranium concentrations, the urine levels decreased an average of 78 percent. However, urine uranium concentrations remained elevated (mean=0.27μg/g), and 87 percent of the urine uranium concentrations exceeded the 95th percentile concentration of the reference population. The results of this investigation demonstrated that after long-term ingestion of uranium in drinking water, elevated concentrations of uranium in urine could be detected up to 10 months after exposure had stopped.  
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  ISSN 0013-9351 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ orloff_human_2004 Serial 136  
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Author (down) Nijsten, G.-J.; Christelis, G.; Villholth, K.G.; Braune, E.; Gaye, C.B. url  openurl
  Title Transboundary aquifers of Africa: Review of the current state of knowledge and progress towards sustainable development and management Type Journal Article
  Year 2018 Publication Journal of Hydrology: Regional Studies Abbreviated Journal  
  Volume 20 Issue Pages 21-34  
  Keywords Africa, Assessment, Governance, Indicators, Transboundary aquifers  
  Abstract Study region Transboundary aquifers (TBAs) of Africa. Study focus Review of work on TBAs in Africa, including an overview of assessments and management efforts that have taken place over the last half century. New hydrological insights Seventy-two TBAs have been mapped in Africa. They underlie 40% of the continent, where 33% of the population lives, often in arid or semi-arid regions. TBA inventories have progressed since 2000 and remain work in progress. Despite their importance only eleven TBAs have been subjected to more detailed studies. Cooperation has been formalised for seven TBAs. Most of these TBAs are in North Africa and the Sahel. The recent global Transboundary Waters Assessment Programme compiled information at the national level to describe TBAs in terms of key indicators related to the water resource, socio-economic, and legal and institutional conditions. Availability of data at national level is low, hampering regional assessment. Comparing indicators, from questionnaire surveys, with those from a global water-use model showed variable levels of agreement, calling for further research. Reports on agreements scoping TBA management, indicate that this may be dealt with within international river/lake agreements, but reported inconsistencies between TBA sharing countries also indicate that implementation is limited. Increasing awareness and support to joint TBA management is noticeable amongst international organisations. However, such cooperation requires long-term commitment to produce impacts at the local level.  
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  ISSN 2214-5818 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ nijsten_transboundary_2018 Serial 93  
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Author (down) Netzer, L.; Kurtzman, D.; Ben-Hur, M.; Livshitz, Y.; Katzir, R.; Nachshon, U. url  openurl
  Title Novel approach to roof rainwater harvesting and aquifer recharge in an urban environment: Dry and wet infiltration wells comparison Type Journal Article
  Year 2024 Publication Water Research Abbreviated Journal  
  Volume 252 Issue Pages 121183  
  Keywords Rainwater harvesting, Managed aquifer recharge, Urban hydrology, Infiltration wells  
  Abstract In urban environments there is a severe reduction of infiltration and groundwater recharge due to the existence of large impervious areas. During rain events, large volumes of water that could have recharged groundwater and surface water bodies are diverted into the municipal drainage system and lost from the freshwater storage. Moreover, extreme rain events impose high peak flows and large runoff volumes, which increase the risk of urban floods. Recent studies have suggested the use of rainwater harvesting for groundwater recharge, as a plausible solution for these challenges in dense urban environments. While the benefits of this approach are well understood, research on its practical, engineering, and hydrological aspects is relatively limited. The objective of the present study was to examine the use of infiltration wells for groundwater recharge with harvested rainwater collected from building rooftops under Mediterranean climate conditions. Two types of wells with similar hydraulic and technical properties were examined: a well that reaches the groundwater (wet well); and a well that discharges the harvested water into the unsaturated zone (dry well). Infiltration capacities of the wells were compared in controlled experiments conducted during summer months, and in operational recharge of harvested rainwater, during winter. Both dry and wet wells were found to be suitable for purposes of groundwater recharge with rooftop-harvested rainwater. Infiltration capacity of the wet well was about seven times greater than the infiltration capacity of the dry well. While the infiltration capacity of the wet well was constant throughout the entire length of the study (∼10 m3/h/m), the dry well infiltration capacity improved during winter (from 0.5 m3/h/m to 1.5 m3/h/m), a result of development of the dry well with time. Considering Tel-Aviv, Israel, as a case study for a dense modern city in a Mediterranean climate, it is demonstrated herein that the use of infiltration wells may reduce urban drainage by ∼40 %.  
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  ISSN 0043-1354 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ Netzer2024121183 Serial 230  
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