Significance of Low‐Velocity Zones on Solute Retention in Rough Fractures
Abstract Natural fractures are characterized by high internal heterogeneity. This internal variability is the cause of flow channeling, which in turn leads to contaminant transport taking place primarily along the high‐velocity channels. Mass exchange between the high‐velocity channels and the low‐v...
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| Format: | Article |
| Language: | English |
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Wiley
2024-04-01
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| Series: | Water Resources Research |
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| Online Access: | https://doi.org/10.1029/2023WR036221 |
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| author | Jordi Sanglas Paolo Trinchero Scott L. Painter Vladimir Cvetkovic Antti Poteri Jan‐Olof Selroos Liangchao Zou |
| author_facet | Jordi Sanglas Paolo Trinchero Scott L. Painter Vladimir Cvetkovic Antti Poteri Jan‐Olof Selroos Liangchao Zou |
| author_sort | Jordi Sanglas |
| collection | DOAJ |
| description | Abstract Natural fractures are characterized by high internal heterogeneity. This internal variability is the cause of flow channeling, which in turn leads to contaminant transport taking place primarily along the high‐velocity channels. Mass exchange between the high‐velocity channels and the low‐velocity zones has the potential to enhance contaminant retention, due to solute diffusion into the low‐velocity zones and subsequent exposure to additional surface area for diffusion into the bordering rock matrix. Here, we derive a random walk particle tracking method for heterogeneous fractures, which includes an additional term to account for the aperture gradient. The method takes into account advection, diffusion in the fracture and matrix diffusion. The developed numerical framework is applied to assess the effect of low‐velocity zones in rough self‐affine fractures. The results show that diffusion into low‐velocity zones has a visible but modest impact on contaminant retention. The magnitude of this impact does not change considerably, regardless of whether diffusion into the rock matrix is considered in the model, and increases for a decreasing average Péclet number of the fracture. |
| format | Article |
| id | doaj-art-05f85a3d869141a99b8626b5dacfb627 |
| institution | OA Journals |
| issn | 0043-1397 1944-7973 |
| language | English |
| publishDate | 2024-04-01 |
| publisher | Wiley |
| record_format | Article |
| series | Water Resources Research |
| spelling | doaj-art-05f85a3d869141a99b8626b5dacfb6272025-08-20T02:09:24ZengWileyWater Resources Research0043-13971944-79732024-04-01604n/an/a10.1029/2023WR036221Significance of Low‐Velocity Zones on Solute Retention in Rough FracturesJordi Sanglas0Paolo Trinchero1Scott L. Painter2Vladimir Cvetkovic3Antti Poteri4Jan‐Olof Selroos5Liangchao Zou6Department of Sustainable Development, Environmental Science and Engineering Royal Institute of Technology Stockholm SwedenAMPHOS 21 Consulting S.L. Barcelona SpainEnvironmental Sciences Division Oak Ridge National Laboratory Oak Ridge TN USADepartment of Sustainable Development, Environmental Science and Engineering Royal Institute of Technology Stockholm SwedenPosiva Oy Eurajoki FinlandDepartment of Sustainable Development, Environmental Science and Engineering Royal Institute of Technology Stockholm SwedenDepartment of Sustainable Development, Environmental Science and Engineering Royal Institute of Technology Stockholm SwedenAbstract Natural fractures are characterized by high internal heterogeneity. This internal variability is the cause of flow channeling, which in turn leads to contaminant transport taking place primarily along the high‐velocity channels. Mass exchange between the high‐velocity channels and the low‐velocity zones has the potential to enhance contaminant retention, due to solute diffusion into the low‐velocity zones and subsequent exposure to additional surface area for diffusion into the bordering rock matrix. Here, we derive a random walk particle tracking method for heterogeneous fractures, which includes an additional term to account for the aperture gradient. The method takes into account advection, diffusion in the fracture and matrix diffusion. The developed numerical framework is applied to assess the effect of low‐velocity zones in rough self‐affine fractures. The results show that diffusion into low‐velocity zones has a visible but modest impact on contaminant retention. The magnitude of this impact does not change considerably, regardless of whether diffusion into the rock matrix is considered in the model, and increases for a decreasing average Péclet number of the fracture.https://doi.org/10.1029/2023WR036221fractured mediarough fracturesmolecular diffusiondiffusion into a rock matrix |
| spellingShingle | Jordi Sanglas Paolo Trinchero Scott L. Painter Vladimir Cvetkovic Antti Poteri Jan‐Olof Selroos Liangchao Zou Significance of Low‐Velocity Zones on Solute Retention in Rough Fractures Water Resources Research fractured media rough fractures molecular diffusion diffusion into a rock matrix |
| title | Significance of Low‐Velocity Zones on Solute Retention in Rough Fractures |
| title_full | Significance of Low‐Velocity Zones on Solute Retention in Rough Fractures |
| title_fullStr | Significance of Low‐Velocity Zones on Solute Retention in Rough Fractures |
| title_full_unstemmed | Significance of Low‐Velocity Zones on Solute Retention in Rough Fractures |
| title_short | Significance of Low‐Velocity Zones on Solute Retention in Rough Fractures |
| title_sort | significance of low velocity zones on solute retention in rough fractures |
| topic | fractured media rough fractures molecular diffusion diffusion into a rock matrix |
| url | https://doi.org/10.1029/2023WR036221 |
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