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Author Shayakhmetov, N.M.; Alibayeva, K.A.; Kaltayev, A.; Panfilov, I. url  openurl
  Title Enhancing uranium in-situ leaching efficiency through the well reverse technique: A study of the effects of reversal time on production efficiency and cost Type Journal Article
  Year 2023 Publication Hydrometallurgy Abbreviated Journal  
  Volume 219 Issue Pages 106086  
  Keywords Economic evaluation, Hydrodynamic enhancement of mineral production, In-situ leaching, Mineral recovery, Optimal reversal time, Well reversing technique  
  Abstract In this study, the application of the Well Reversal Technique (WRT) and the impact of reversal time on the efficiency of uranium mining via In-Situ Leaching (ISL) were investigated. A prevalent issue in ISL mineral extraction is the formation of stagnant zones caused by limited access of the lixiviant, which leads to increased operating expenditures. The WRT, which involves altering the function of some wells from injection to production or vice versa, is a potential solution to this problem. The efficiency of WRT is heavily dependent on the well pattern and reversal time. Two commonly used well patterns in ISL are the 9-spot (row arrangement) and 7-spot (hexagonal arrangement). The objective of this study was to determine the optimal reversal time for a 9-spot well pattern through mathematical modeling of hydrodynamic and physico-chemical processes and subsequent economic assessment. A mathematical model of uranium extraction processes was developed using the principles of mass conservation, Darcy’s, and mass action laws. The results obtained for a 9-spot well pattern without reversal, with two reversal options, and a 7-spot scheme were analyzed comparatively. The 7-spot scheme without reversal was found to be the most effective of the options examined. The application of WRT on a 9-spot well pattern allows to enhance production efficiency to a level comparable to that of a 7-spot well pattern. Additionally, the effect of reversal time on recovery was studied based on two well reversal options. The results from calculation revealed that the optimal scenario was when the well reversal is conducted immediately after the time point at which the average concentration of the pregnant solution in the production wells reaches its peak value. The overall efficiency of WRT application was determined through economic calculations of capital (CAPEX) and operating (OPEX) expenditures. Based on economic calculations, it was determined that the utilization of WRT results in a 3–18% increase in mineral production efficiency for a 9-point scheme, depending on the chosen reversal method.  
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  ISSN 0304-386x ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ shayakhmetov_enhancing_2023 Serial 203  
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Author Zhou, Y.; Li, G.; Xu, L.; Liu, J.; Sun, Z.; Shi, W. url  openurl
  Title Uranium recovery from sandstone-type uranium deposit by acid in-situ leaching – an example from the Kujieertai Type Journal Article
  Year 2020 Publication Hydrometallurgy Abbreviated Journal  
  Volume 191 Issue Pages 105209  
  Keywords Acid in-situ leaching, Sandstone-type uranium deposit, Uranium deportment in the ore, Uranium recovery, Water-rock interaction  
  Abstract The factors influencing uranium recovery in water-rock systems during acid in-situ leaching (ISL) were studied at the Kujieertai uranium deposit in Xinjiang. Using an ISL unit, a field leach trial (FLT) had been carried out to test the sequential effects of a leaching solution without oxidant (H2SO4 solution 4–8 g/L) and a leaching solution with oxidant (H2SO4 3–7 g/L, and Fe (III) 2–6 g/L). The observation of the leaching process revealed clearly defined stages of uranium release from the solid mineral to solution. Uranium mobilization from solid mineral into solution can be described in four stages. At the beginning of the acid ISL process, there was no oxidant to be added to the leaching solution and the desorption of hexavalent uranyl ions in the open pores, as well as dissolution of hexavalent uranium minerals, led to a short-term peak in the pregnant solution, which happened while pH decreased from about 5.3 to 2.62. Following the depletion of the adsorbed hexavalent uranium and a decline in uranium dissolution intensity, the addition of Fe(III) facilitated the oxidation of tetravalent uranium, which enabled intensive uranium mobilization again. During this process, the dissolution of uranium had a strong positive correlation with the reduction of Fe(III) and Eh in the leach solution. Beside hydrochemical factors, the deportment of uranium was also an important factor affecting uranium recovery. Uranium located in the open pores can be completely exposed to the solution and the mobilization intensity was significantly affected by hydrogeochemical conditions; but the uranium present in microfissures and in the ore matrix could not be fully exposed to the solution, so, their dissolution intensity was primarily controlled by corrosion and permeability of the ore. In general, the hydrogeochemical conditions and the deportment of uranium were the external and internal factors that significantly affected the dissolution and recovery of uranium in the early and middle stages of the FLT. However, in the latest stages, due to uranium depletion, enhancing the chemical potential of the leaching solution, specifically acidity and/or the amount of oxidant, had little improvement on uranium recovery.  
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  ISSN 0304-386x ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ zhou_uranium_2020 Serial 205  
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Author Tan, K.; Li, C.; Liu, J.; Qu, H.; Xia, L.; Hu, Y.; Li, Y. url  openurl
  Title A novel method using a complex surfactant for in-situ leaching of low permeable sandstone uranium deposits Type Journal Article
  Year 2014 Publication Hydrometallurgy Abbreviated Journal  
  Volume 150 Issue Pages 99-106  
  Keywords Complex surfactant, In-situ leaching of uranium mining, Leaching kinetics, Low permeable sandstone uranium deposit, Resin adsorption and elution  
  Abstract Applications of a complex surfactant developed in-house to in-situ leaching of low permeable sandstone uranium deposits are described based on results from agitation leaching, column leaching, resin adsorption, and elution experiments using uranium containing solution from the in-situ leaching site. The results of agitation leaching experiments show that adding surfactant with different concentrations into leaching solution improves the leaching rate of uranium. The maximum leaching rate of uranium from agitation leaching reached 92.6% at an added surfactant concentration of 10mg/l. Result of column leaching experiment shows that adding surfactant with varying concentrations into leaching solutions increased the permeability coefficient of ore-bearing layer by 42.7–86.8%. The leaching rate of uranium from column leaching increased by 58.0% and reached 85.8%. The result of kinetic analysis shows that for the extraction of uranium controlled by diffusion without surfactant the apparent rate constant 0.0023/d changed to 0.0077/d for the extraction with surfactant controlled by both diffusion and surface chemical reactions. Results from resin adsorption and elution experiments show that there was no influence on resin adsorption and elution of uranium with an addition of 50mg/l surfactant to production solution from in-situ leaching. The adsorption curve, sorption capacity of resin, recycling of resin remained the same as without adding any surfactant. Introducing complex surfactant to leaching solution increased the peak concentration of uranium in eluents, reduced the residual uranium content in resin, and promoted the elution efficiency. The method of using a complex surfactant for in-situ leaching is useful for low permeable sandstone uranium deposits.  
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  ISSN 0304-386x ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ tan_novel_2014 Serial 201  
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Author Boumaiza, L.; Ammar, S.B.; Chesnaux, R.; Stotler, R.L.; Mayer, B.; Huneau, F.; Johannesson, K.H.; Levison, J.; Knöller, K.; Stumpp, C. url  openurl
  Title Nitrate sources and transformation processes in groundwater of a coastal area experiencing various environmental stressors Type Journal Article
  Year 2023 Publication Journal of Environmental Management Abbreviated Journal  
  Volume 345 Issue Pages 118803  
  Keywords Aquifer, Denitrification, MixSIAR, Nitrate, Nitrification, Stable isotopes  
  Abstract In coastal salinized groundwater systems, contamination from various nitrate (NO3) inputs combined with complex hydrogeochemical processes make it difficult to distinguish NO3 sources and identify potential NO3 transformtation processes. Effective field-based NO3 studies in coastal areas are needed to improve the understanding of NO3 contamination dynamics in groundwater of such complex coastal systems. This study focuses on a typical Mediterranean coastal agricultural area, located in Tunisia, experiencing substantial NO3 contamination from multiple anthropogenic sources. Here, multiple isotopic tracers (δ18OH2O, δ2HH2O, δ15NNO3, δ18ONO3, and δ11B) combined with a Bayesian isotope MixSIAR model are used (i) to identify the major NO3 sources and their contributions, and (ii) to describe the potential NO3 transformation processes. The measured NO3 concentrations in groundwater are above the natural baseline threshold, suggesting anthropogenic influence. The measured isotopic composition of NO3 indicates that manure, soil organic matter, and sewage are the potential sources of NO3, while δ11B values constrain the NO3 contamination to manure; a finding that is supported by the results of MixSIAR model revealing that manure-derived NO3 dominates over other likely sources. Nitrate derived from manure in the study area is attributed to organic fertilizers used to promote crop growth, and livestock that deposit manure directly on the ground surface. Evidence for ongoing denitrification in groundwaters of the study area is supported by an enrichment in both 15N and 18O in the remaining NO3, although isotopic mass balances between the measured and the theoretical δ18ONO3 values also suggest the occurrence of nitrification. The simultaneous occurrence of these biogeochemical processes with heterogeneous distribution across the study area reflect the complexity of interactions within the investigated coastal aquifer. The multiple isotopic tracer approach used here can identify the effect of multiple NO3 anthropogenic activities in coastal environments, which is fundamental for sustainable groundwater resources management.  
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  Call Number THL @ christoph.kuells @ boumaiza_nitrate_2023 Serial 170  
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Author Dąbrowska, J.; Orellana, A.E.M.; Kilian, W.; Moryl, A.; Cielecka, N.; Michałowska, K.; Policht-Latawiec, A.; Michalski, A.; Bednarek, A.; Włóka, A. url  openurl
  Title Between flood and drought: How cities are facing water surplus and scarcity Type Journal Article
  Year 2023 Publication Journal of Environmental Management Abbreviated Journal  
  Volume 345 Issue Pages 118557  
  Keywords Urban ecosystem management, Urban floods, Urban droughts, Nature-based solutions, Climate change, Urban resilience  
  Abstract Droughts and floods are weather-related hazards affecting cities in all climate zones and causing human deaths and material losses on all inhabited continents. The aim of this article is to review, analyse and discuss in detail the problems faced by urban ecosystems due to water surplus and scarcity, as well as the need of adaptation to climate change taking into account the legislation, current challenges and knowledge gaps. The literature review indicated that urban floods are much more recognised than urban droughts. Amongst floods, flash floods are currently the most challenging, which by their nature are difficult to monitor. Research and adaptation measures related to water-released hazards use cutting-edge technologies for risk assessment, decision support systems, or early warning systems, among others, but in all areas knowledge gaps for urban droughts are evident. Increasing urban retention and introducing Low Impact Development and Nature-based Solutions is a remedy for both droughts and floods in cities. There is the need to integrate flood and drought disaster risk reduction strategies and creating a holistic approach.  
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  Call Number THL @ christoph.kuells @ Dabrowska2023118557 Serial 227  
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Author Mabrouk, M.; Han, H.; Fan, C.; Abdrabo, K.I.; Shen, G.; Saber, M.; Kantoush, S.A.; Sumi, T. url  openurl
  Title Assessing the effectiveness of nature-based solutions-strengthened urban planning mechanisms in forming flood-resilient cities Type Journal Article
  Year 2023 Publication Journal of Environmental Management Abbreviated Journal  
  Volume 344 Issue Pages 118260  
  Keywords Flood, Urban planning, Sustainable cities, LID, Natural-based solutions, Alexandria  
  Abstract Cities have experienced rapid urbanization-induced harsh climatic events, especially flooding, inevitably resulting in negative and irreversible consequences for urban resilience and endangering residents’ lives. Numerous studies have analyzed the effects of anthropogenic practices (land use changes and urbanization) on flood forecasting. However, non-structural mitigation’s effectiveness, like Nature-Based Solutions (NBS), has yet to receive adequate attention, particularly in the Middle East and North Africa (MENA) region, which have become increasingly significant and indispensable for operationalizing cities efficiently. Therefore, our study investigated the predictive influence of incorporating one of the most common NBS strategies called low-impact development tools (LID) (such as rain gardens, bio-retention cells, green roofs, infiltration trenches, permeable pavement, and vegetative swale) during the urban planning of Alexandria, Egypt, which experiences the harshest rainfall annually and includes various urban patterns. City characteristics-dependent 14 LID scenarios were simulated with recurrence intervals ranging from 2 to 100 years using the LID Treatment Train Tool (LID TTT), depending on calibrated data from 2015 to 2020, by the Nash-Sutcliffe efficiency index and deterministic coefficient, and root-mean-square error with values of 0.97, 0.91, and 0.31, respectively. Our findings confirmed the significant effectiveness of combined LID tools on total flood runoff volume reduction by 73.7%, revealing that different urban patterns can be used in flood-prone cities, provided LID tools are considered in city planning besides grey infrastructure to achieve optimal mitigation. These results, which combined multiple disciplines and were not explicitly mentioned in similar studies in developing countries, may assist municipalities’ policymakers in planning flood-resistant, sustainable cities.  
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  Call Number THL @ christoph.kuells @ Mabrouk2023118260 Serial 232  
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Author Baptista, V.S.G.; Coelho, V.H.R.; Bertrand, G.F.; Silva, G.B.L. da; Caicedo, N.O.L.; Montenegro, S.M.G.L.; Stefan, C.; Glass, J.; Heim, R.; Conrad, A.; Almeida, C. das N. url  openurl
  Title Rooftop water harvesting for managed aquifer recharge and flood mitigation in tropical cities: Towards a strategy of co-benefit evaluations in João Pessoa, northeast Brazil Type Journal Article
  Year 2023 Publication Journal of Environmental Management Abbreviated Journal  
  Volume 342 Issue Pages 118034  
  Keywords Flood control, Groundwater, Injection well, Stormwater management, Urban drainage, Aquifer storage and recovery  
  Abstract Intense urbanisation in many coastal areas has led to intensification of groundwater consumption, while reducing permeable areas and increasing the frequency and magnitude of flooding. Among the potential strategies to compensate for these adverse effects, which are expected to become worse as a result of climate change, rooftop rainwater harvesting (RWH) in combination with managed aquifer recharge (MAR), may be indicated. This work investigated the performance of different configurations of such a system, tested as a twofold sustainable stormwater and domestic water management tool in a tropical metropole (João Pessoa, Brazil). This area located over a sedimentary aquifer system illustrates the water security challenges of densely urbanised areas in southern cities. To that end, several configurations of rooftop catchments and storage volumes were evaluated, by simulating a MAR-RWH system connected to the regional unconfined aquifer (Barreiras Formation) through a 6″ diameter injection well. Rainfall-runoff-recharge processes and water balances were simulated using monitored high-temporal resolution rainfall data. The results showed that catchments ranging from 180 to 810 m2, connected to tanks from 0.5 to 30.0 m³, are the optimal solutions in terms of efficient rainwater retention and peak flow reduction. These solutions provided mean annual estimates of aquifer recharge between 57 and 255 m³/yr from 2004 to 2019. The results of this study highlight the opportunity for MAR schemes to reconcile stormwater management and water supply goals.  
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  Call Number THL @ christoph.kuells @ Baptista2023118034 Serial 237  
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Author Custódio, D.A.; Ghisi, E. url  openurl
  Title Impact of residential rainwater harvesting on stormwater runoff Type Journal Article
  Year 2023 Publication Journal of Environmental Management Abbreviated Journal  
  Volume 326 Issue Pages 116814  
  Keywords Rainwater harvesting, Residential buildings, Stormwater runoff, Floods, Computer simulation  
  Abstract Population increase, climate change and soil impermeability are factors causing floods in large urban centres. Such places also always have water shortage problems. This research aims to evaluate the influence of rainwater harvesting in residential buildings on stormwater in a basin located in southern Brazil (Rio Cachoeira Basin). Urbanised and non-urbanised areas, soil types, curve numbers and time of concentration of each sub-basin were taken into account. Through the HEC-HMS programme, it was possible to calculate hydrographs for the base scenario (when there is no rainwater harvesting). Then, rainwater tanks for the residential buildings were sized using the computer programme Netuno. In the second scenario, there is rainwater harvesting in all residential buildings. Thus, the hydrographs for the second scenario were also calculated. The peak flow reduction potentials for the sub-basins ranged from 2.7% to 14.3%. The highest percentage (14.3%) did not occur in the sub-basin with the most extensive roof area; such highest peak flow reduction occurred in Bom Retiro sub-basin. In Bom Retiro sub-basin, there are more houses than multi-storey residential buildings. Even when considering the full potential of rainwater harvesting for roof areas of all existing buildings in the Rio Cachoeira Basin, the average potential reduction in peak flow was 7.2%. The conclusion is that rainwater tanks in residential buildings have little influence on stormwater runoff, and the stormwater runoff will be less affected when the area of the hydrographic basin is larger. Thus, the reduction in peak flows is insignificant when considering the flooding in the region.  
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  Call Number THL @ christoph.kuells @ Custodio2023116814 Serial 231  
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Author Pree, T.A.D. url  openurl
  Title The politics of baselining in the Grants uranium mining district of northwestern New Mexico Type Journal Article
  Year 2020 Publication Journal of Environmental Management Abbreviated Journal  
  Volume 268 Issue Pages 110601  
  Keywords Critical stakeholder analysis, Environmental cleanup, Environmental monitoring, Mining reclamation/remediation/restoration, Politics of baselining  
  Abstract During the second half of the twentieth century, northwestern New Mexico served as the primary production site for one of the world’s largest nuclear arsenals. From 1948 to 1970 the “Grants uranium district” provided almost half of the total uranium ore accumulated by the United States federal government for the production of nuclear weapons, in addition to becoming a national source for commercial nuclear energy from the late 1960s to the early 1990s. By the twenty-first century, after a prolonged period of economic decline that began in the late 1970s, all uranium mining and milling in New Mexico had ceased, leaving a legacy of environmental health impacts. What was once referred to as “The Uranium Capital of the World” now encompasses over a thousand abandoned uranium mines and seven massive uranium mill tailings piles, which are associated with airborne and soil contamination as well as groundwater plumes of uranium and other contaminants of concern, in a landscape that has been fractured by underground mine workings and punctured by thousands of exploratory boreholes. This article presents an ethnographic study of the diverse forms of expertise involved in monitoring and managing the mine waste and mill tailings. Drawing from over two years of ethnographic research, I describe the relationship between different stakeholders from local communities, government agencies, and transnational mining corporations as they deliberate about the possibility of cleaning up the former mining district. My thesis is that the possibility of cleaning up the Grants district hinges on the “politics of baselining”—a term I introduce to describe the relationship between stakeholders and their competing environmental models and hydrogeological theories; each accounts for a different geological past prior to mining that can be deemed “natural,” as the background against which to measure the anthropogenic impacts from mining.  
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  Call Number THL @ christoph.kuells @ pree_politics_2020 Serial 151  
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Author French, K. url  openurl
  Title Indigenous knowledge, water management, and learning from our collective past Type Journal Article
  Year 2022 Publication Journal of Anthropological Archaeology Abbreviated Journal  
  Volume 68 Issue Pages 101466  
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  ISSN 0278-4165 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ French2022101466 Serial 253  
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