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Netzer, L., Kurtzman, D., Ben-Hur, M., Livshitz, Y., Katzir, R., & Nachshon, U. (2024). Novel approach to roof rainwater harvesting and aquifer recharge in an urban environment: Dry and wet infiltration wells comparison. Water Research, 252, 121183.
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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Haque, N., & Norgate, T. (2014). The greenhouse gas footprint of in-situ leaching of uranium, gold and copper in Australia. Journal of Cleaner Production, 84, 382–390.
Abstract: In-situ leaching (ISL) is a chemical method for recovering useful minerals and metals directly from underground ore bodies which is also referred to as ‘solution mining’. ISL is commonly used for uranium mining, accounting for about 45% of global production. The main benefits are claimed to be a lower environmental impact in terms of visual disturbances, emissions, lower energy use, cost compared with conventional open-cut or underground mining methods, and potential utilisation of lower grade resources. However, there is a lack of reported studies on the assessment of the environmental impacts of ISL, particularly greenhouse gas (GHG) emissions using life cycle assessment (LCA) methodology. The SimaPro LCA software was used to estimate the GHG footprint of the ISL of uranium, gold and copper. The total GHG emissions were estimated to be 38.0 kg CO2-e/kg U3O8 concentrate (yellowcake), 29 t CO2-e/kg gold, and 4.78 kg CO2-e/kg Cu. The GHG footprint of ISL uranium was significantly lower than that of conventional mining, however, the footprints of copper and gold were not much less compared with conventional mining methods. This is due to the lower ore grade of ISL deposits and recovery compared with high ore grades and recovery of conventional technology. Additionally, the use of large amount of electricity for pumping in case of ISL contributes to this result. The electricity consumed in pumping leaching solutions was by far the greatest contributor to the well-field related activities associated with ISL of uranium, gold and copper. The main strategy to reduce the GHG footprint of ISL mining should be to use electricity derived from low emission sources. In particular, renewable sources such as solar would be suitable for ISL as these operations are typically in remote locations with smaller deposits compared with conventional mining sites.
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Rossetto, R., Filippis, G. D., Borsi, I., Foglia, L., Cannata, M., Criollo, R., et al. (2018). Integrating free and open source tools and distributed modelling codes in GIS environment for data-based groundwater management. Environmental Modelling & Software, 107, 210–230.
Abstract: Integrating advanced simulation techniques and data analysis tools in a freeware Geographic Information System (GIS) provides a valuable contribution to the management of conjunctive use of groundwater (the world’s largest freshwater resource) and surface-water. To this aim, we describe here the FREEWAT (FREE and open source software tools for WATer resource management) platform. FREEWAT is a free and open source, QGIS-integrated interface for planning and management of water resources, with specific attention to groundwater. The FREEWAT platform couples the power of GIS geo-processing and post-processing tools in spatial data analysis with that of process-based simulation models. The FREEWAT environment allows storage of large spatial datasets, data management and visualization, and running of several distributed modelling codes (mainly belonging to the MODFLOW family). It simulates hydrologic and transport processes, and provides a database framework and visualization capabilities for hydrochemical analysis. Examples of real case study applications are provided.
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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., et al. (2023). 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. Journal of Environmental Management, 342, 118034.
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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Zeng, S., Song, J., Sun, B., Wang, F., Ye, W., Shen, Y., et al. (2023). Seepage characteristics of the leaching solution during in situ leaching of uranium. Nuclear Engineering and Technology, 55(2), 566–574.
Abstract: Investigating the seepage characteristics of the leaching solution in the ore-bearing layer during the in situ leaching process can be useful for designing the process parameters for the uranium mining well. We prepared leaching solutions of four different viscosities and conducted experiments using a self-developed multifunctional uranium ore seepage test device. The effects of different viscosities of leaching solutions on the seepage characteristics of uranium-bearing sandstones were examined using seepage mechanics, physicochemical seepage theory, and dissolution erosion mechanism. Results indicated that while the seepage characteristics of various viscosities of leaching solutions were the same in rock samples with similar internal pore architectures, there were regular differences between the saturated and the unsaturated stages. In addition, the time required for the specimen to reach saturation varied with the viscosity of the leaching solution. The higher the viscosity of the solution, the slower the seepage flow from the unsaturated stage to the saturated stage. Furthermore, during the saturation stage, the seepage pressure of a leaching solution with a high viscosity was greater than that of a leaching solution with a low viscosity. However, the permeability coefficient of the high viscosity leaching solution was less than that of a low viscosity leaching solution.
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