GROUNDWATER FLOW AND MULTI-COMPONENT REACTIVE TRANSPORT SIMULATION OF ACID MINE DRAINAGE AT A FORMER MINE SITE

2020 ◽  
Vol 19 (76) ◽  
Author(s):  
Rabindra Neupane
2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Meriem Lghoul ◽  
Karim Sbihi ◽  
Abdelkabir Maqsoud ◽  
Rachid Hakkou ◽  
Azzouz Kchikach

AbstractIn this study, we present the efficiency of remediation scenario to attenuate the impact of acid mine drainage (AMD) contamination in the Kettara abandoned mine site. The study focuses on the AMD groundwater contamination of the Sarhlef shists aquifer. To predict the evolution of AMD groundwater contamination in the Kettara mine site under remediation scenario, a model of groundwater flow and AMD transport was performed.Piezometric heads were measured at the dry and wet periods from eleven wells located downstream of mine wastes. To elaborate a conceptual groundwater flow model, we faced with to the heterogeneity and anisotropy of fractured Sarhlef shists aquifer. Consequently, the study focused on the use of various approaches: 1. The inverse modeling by the CMA-ES algorithm is adopted as an alternative approach to determine hydraulic parameters indirectly, and 2. the model is treated as an equivalent porous media (EPM). The groundwater flow model was carried out in steady-state and transient conditions in the dry and wet periods using the PMWIN interface. The obtained results are satisfactory and show an excellent correlation between measured and computed heads. Contaminant transport model is used to solve the advection–dispersion equation and to generate the AMD concentration by MT3D via the PMWIN interface. A sensitivity analysis of the dispersivity coefficient is carried out. The AMD transport simulation was computed during periods of 1, 5 and 10 years, and the performed model indicates that the simulated concentrations under remediation scenario are reduced 1000 times comparing to the current concentrations. The study revealed a necessary approach in addressing an environmental issue for the AMD contamination. The results of the study will be a start-up for further research work in the study area and implementing it for the prevention of AMD propagation plume.


2016 ◽  
Vol 53 (5) ◽  
pp. 828-838 ◽  
Author(s):  
Mamert Mbonimpa ◽  
Médard Bouda ◽  
Isabelle Demers ◽  
Mostafa Benzaazoua ◽  
Denis Bois ◽  
...  

Lime treatment of acid mine drainage (AMD) generates sludge that is commonly stored in ponds for dewatering. The use of soil-aged sludge-based mixtures for mine site rehabilitation can allow the emptying of existing basins, thus extending their storage capacity, reducing the volume of the borrow soil pit required for mine site rehabilitation, and consequently reducing the mine footprint. The authors investigated the geotechnical properties of silty soil–sludge mixtures (SSMs) as possible components of covers with capillary barrier effects (CCBEs) to prevent AMD generation from mine waste. SSMs with β values of 10%, 15%, 20%, and 25% sludge (β = wet sludge mass / wet soil mass) were studied. Two water contents were considered for each of the mixture components: 175% and 200% for the sludge and 7.5% and 12.5% for the soil. Results indicate that saturated hydraulic conductivity (ksat) values were in the range of 10−5 cm/s for the soil and SSMs at void ratios ranging from 0.28 to 0.53, with values decreasing slightly when β was increased from 0% to 25%. The air-entry value (AEV) increased from 20 kPa for the soil alone to 35 kPa for the SSM with β = 25%. These values of ksat and AEV are comparable to those of materials used in the moisture retention layers of existing efficient CCBEs. However, the volumetric shrinkage increased from about 2% for the soil alone to values ranging between 24% and 32% for the SSM with β = 25%, depending on the initial water contents of the components. Tools are provided to estimate to which extent the use of sludge in SSMs can reduce the volume of borrow natural soil required for a moisture retention layer of a CCBE.


2004 ◽  
Vol 38 (11) ◽  
pp. 3131-3138 ◽  
Author(s):  
Richard T. Amos ◽  
K. Ulrich Mayer ◽  
David W. Blowes ◽  
Carol J. Ptacek

2019 ◽  
Vol 268 ◽  
pp. 06003 ◽  
Author(s):  
Carlito Tabelin ◽  
Asuka Sasaki ◽  
Toshifumi Igarashi ◽  
Shingo Tomiyama ◽  
Mylah Villacorte-Tabelin ◽  
...  

Acid mine drainage (AMD), the very acidic and highly contaminated leachate generated in closed/abandoned mines, is commonly managed by neutralization to raise the pH and precipitate most of the heavy metals. Although effective, this approach does not generate any product of economic value, so it is very costly and unsustainable in the long-term. Unfortunately, there are currently no effective alternatives to neutralization, and one way to improve the sustainability of this process is to reduce the volume of AMD generated and/or the concentration of heavy metals. The tailings dam investigated in this study is located in northern Hokkaido, Japan. Detailed characterization of borehole core samples showed that even after almost 40 years of exposure to the environment, the tailings still contain pyrite (FeS2) and substantial amounts of copper (Cu) and zinc (Zn). Reactive-transport modeling using Visual MODFLOW predicted that AMD quality would likely continue to deteriorate with time and that treatment should be continued for at least 1,000 years. The model also predicted that a barrier with low permeability installed downstream of the tailings dam or ground sealing techniques for recharge reduction could lower the volume of AMD and concentration of Zn from the site.


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