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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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  ISSN (up) 0301-4797 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ Baptista2023118034 Serial 237  
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Author Kurmanseiit, M.B.; Tungatarova, M.S.; Royer, J.-J.; Aizhulov, D.Y.; Shayakhmetov, N.M.; Kaltayev, A. url  openurl
  Title Streamline-based reactive transport modeling of uranium mining during in-situ leaching: Advantages and drawbacks Type Journal Article
  Year 2023 Publication Hydrometallurgy Abbreviated Journal  
  Volume 220 Issue Pages 106107  
  Keywords 3D modeling, In-situ leaching, Reactive transport model, Streamlines, Uranium recovery  
  Abstract Reactive transport modeling is known to be computationally intensive when applied to 3D problems. Transforming sequential computing on the computer processor units (CPU) into parallelized computation on the high-performance parallel graphic processor units (GPU) is a classical approach to increasing computational performance. Another complementary approach is to decompose a complex 3D modeling problem into a set of simpler 1D problems using streamline approaches which can be easily parallelized, therefore reducing computation time. This paper investigates solutions to the equations governing dissolution and transport using streamlines coupled with a parallelization approach. In addition, an analytical solution to the dissolution and transfer equations of uranium describing the In-Situ Leaching (ISL) mining recovery is found using an approximation series to the 2nd order. The analytical solution is compared to the 1D numerical resolution along the streamlines and to the 3D simulation results superimposed on the streamline. Both approaches give similar results with a relative error of \textless2 % (2%). The proposed methodology is then applied to a case study in which the classical 3D resolution is compared to the newly suggested streamline solution, demonstrating that the streamline approach increases computational performances by a factor ranging from hundred to thousand depending on the complexity of the grid-block model.  
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  ISSN (up) 0304-386x ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ kurmanseiit_streamline-based_2023 Serial 190  
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Author Uhrie, J.L.; Drever, J.I.; Colberg, P.J.S.; Nesbitt, C.C. url  openurl
  Title In situ immobilization of heavy metals associated with uranium leach mines by bacterial sulfate reduction Type Journal Article
  Year 1996 Publication Hydrometallurgy Abbreviated Journal  
  Volume 43 Issue 1 Pages 231-239  
  Keywords  
  Abstract Laboratory experiments with mixed populations of sulfate-reducing bactreria were shown to mediate the removal of milligrams/liter concentrations of uranium, selenium, arsenic and vanadium from aqueous solution via reduction, precipitation and adsorption. Results of laboratory experiments with active sulfidogenic biomass suggest that injection of sulfate and a source of carbon could enhance anaerobic microbial activity in and around uranium leach mines leading to in situ immobilization contaminating metals.  
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  ISSN (up) 0304-386x ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ uhrie_situ_1996 Serial 197  
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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 (up) 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 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 (up) 0304-386x ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ shayakhmetov_enhancing_2023 Serial 203  
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