Reactive transport modelling of acid mine drainage within discretely fractured porous media: Plume evolution from a surface source zone

2012 ◽  
Vol 38 ◽  
pp. 259-270 ◽  
Author(s):  
J. Molson ◽  
M. Aubertin ◽  
B. Bussière
Keyword(s):  
Porous Media ◽  
Acid Mine Drainage ◽  
Reactive Transport ◽  
Mine Drainage ◽  
Fractured Porous Media ◽  
Source Zone ◽  
Reactive Transport Modelling ◽  
Surface Source ◽  
Transport Modelling ◽  
Acid Mine

Reactive Transport Modeling of Column Experiments for the Remediation of Acid Mine Drainage

2004 ◽  
Vol 38 (11) ◽  
pp. 3131-3138 ◽  
Author(s):  
Richard T. Amos ◽  
K. Ulrich Mayer ◽  
David W. Blowes ◽  
Carol J. Ptacek
Keyword(s):  
Acid Mine Drainage ◽  
Reactive Transport ◽  
Mine Drainage ◽  
Transport Modeling ◽  
Column Experiments ◽  
Reactive Transport Modeling ◽  
Acid Mine

scholarly journals Prediction of acid mine drainage formation and zinc migration in the tailings dam of a closed mine, and possible countermeasures

2019 ◽  
Vol 268 ◽  
pp. 06003 ◽  
Author(s):  
Carlito Tabelin ◽  
Asuka Sasaki ◽  
Toshifumi Igarashi ◽  
Shingo Tomiyama ◽  
Mylah Villacorte-Tabelin ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Acid Mine Drainage ◽  
Reactive Transport ◽  
Mine Drainage ◽  
Economic Value ◽  
Abandoned Mines ◽  
Tailings Dam ◽  
Visual Modflow ◽  
Acid Mine

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.

scholarly journals Combining innovative experimental approaches and cross-scale reactive transport modelling for assessing coupled hydrogeochemical processes at interfaces in deep geological repositories for radioactive waste

2021 ◽  
Vol 1 ◽  
pp. 105-107
Author(s):  
Jenna Poonoosamy ◽  
Martina Klinkenberg ◽  
Mara Lönartz ◽  
Yuankai Yang ◽  
Guido Deissmann ◽  
...  
Keyword(s):  
Porous Media ◽  
Radioactive Waste ◽  
Reactive Transport ◽  
Mineral Dissolution ◽  
Reactive Transport Modelling ◽  
Transport Models ◽  
Transport Modelling ◽  
Host Rocks ◽  
Dissolution And Precipitation ◽  
Mineral Dissolution And Precipitation

Abstract. Deep geological repositories with a multi-barrier concept are foreseen by various countries for the disposal of high-level radioactive waste. A reliable and consistent assessment of the safety of these repositories over time scales of some hundred thousand years requires an advancement of process understanding. Simulation tools need to be developed for a close-to-reality description of repository evolution scenarios. This is especially required to resolve the challenging task of comparing and assessing the safety of different repository concepts in different host rocks within the German site-selection process. The construction of underground galleries and geotechnical barriers in the host rock formation and the emplacement of nuclear waste packages will create perturbations induced by chemical, thermal and pressure gradients at the interfaces of the different barriers, leading to mineral dissolution and precipitation to achieve re-equilibration. Such coupled hydrogeochemical processes generate non-linear responses in transport and mechanical properties of barrier materials and host rocks, which have to be taken into account for a more rigorous assessment of repository system evolution. Reactive transport modeling (RTM) can be applied to investigate these perturbations and processes across temporal and spatial scales, from the micro-scale at interfaces via the repository near field to the entire repository system – information not accessible through experiments alone. Although RTM is capable of addressing highly complex hydrogeochemical phenomena, the application of RTM codes to real systems is impeded by the often simplified description of coupled processes. To enhance the predictive capabilities of reactive transport models and to gain fundamental insights into the coupling between solute and radionuclide transport properties (e.g., permeability and diffusivity) of porous media and dissolution/precipitation processes, we conducted experiments on “simplified” chemical systems combined with pore-scale and continuum-scale reactive transport modelling to study processes in isolation, with the final aim of improving conceptual approaches for process couplings implemented in reactive transport codes. In this context, we investigated the effects of coupled mineral dissolution and precipitation in porous media on changes in permeability using flow-through experiments conducted in a magnetic resonance imaging scanner, which enabled the in situ investigation of porosity evolution in combination with monitoring changes in permeability and mineralogy. Our observations showed that classical implementations in reactive transport codes such as the Kozeny–Carman equation (Carman, 1937) failed to reproduce the changes in permeability and that more sophisticated approaches are required (Poonoosamy et al., 2020a, b). Moreover, we developed a novel “lab-on-a-chip” setup, i.e., micronized counter diffusion reactors with in operando 3D Raman tomography (Poonoosamy et al., 2019, 2020c), which enables evaluation of the alteration in pore architecture and study of the effect of coupled mineral dissolution and precipitation on the diffusive transport of solutes and radionuclides in porous media. Our approach enables the development of process-based theoretical models which allow for improvements in RTM codes and for predicting the evolution of perturbed interfaces in waste repositories, thus building confidence in the predictive capabilities of reactive transport models and reducing uncertainties with respect to future repository evolution.

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