Effect of soil textural characteristics on longitudinal dispersion in saturated porous media
This study focuses on the effects of soil textural heterogeneity on longitudinal dispersion under saturation conditions. A series of solute transport experiments were carried out using saturated soil columns packed with two filter sands and two mixtures of these sands, having d50 values of 95, 324,...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Sciendo
2021-06-01
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| Series: | Journal of Hydrology and Hydromechanics |
| Subjects: | |
| Online Access: | https://doi.org/10.2478/johh-2021-0004 |
| _version_ | 1828949538669330432 |
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| author | Mahmoodlu Mojtaba G. Raoof Amir van Genuchten Martinus Th. |
| author_facet | Mahmoodlu Mojtaba G. Raoof Amir van Genuchten Martinus Th. |
| author_sort | Mahmoodlu Mojtaba G. |
| collection | DOAJ |
| description | This study focuses on the effects of soil textural heterogeneity on longitudinal dispersion under saturation conditions. A series of solute transport experiments were carried out using saturated soil columns packed with two filter sands and two mixtures of these sands, having d50 values of 95, 324, 402, and 480 µm, subjected to four different steady flow rates. Values of the dispersion coefficient (D) were estimated from observed in-situ distributions of calcium chlo-ride, injected as a short nonreactive tracer pulse, at four different locations (11, 18, 25, 36 cm). Analyses of the observed distributions in terms of the standard advection-dispersion equation (ADE) showed that D increased nonlinearly with travel distance and higher Peclet numbers+. The dispersion coefficient of sand sample S1 with its largest average particle size (d50) was more affected by the average pore-water velocity than sample S4 having the smallest d50. Results revealed that for a constant velocity, D values of sample S1 were much higher than those of sample S4, which had the smallest d50. A correlation matrix of parameters controlling the dispersion coefficient showed a relatively strong positive relationship between D and the Peclet number. In contrast, almost no correlation was evident between D and porosity as well as grain size. The results obtained with the four sandy matrices were consistent and proved that the dispersion coefficient depends mainly on the particle size. |
| first_indexed | 2024-12-14T06:09:16Z |
| format | Article |
| id | doaj.art-b8ac65c5c927458d8e775c4cb1df28ee |
| institution | Directory Open Access Journal |
| issn | 1338-4333 |
| language | English |
| last_indexed | 2024-12-14T06:09:16Z |
| publishDate | 2021-06-01 |
| publisher | Sciendo |
| record_format | Article |
| series | Journal of Hydrology and Hydromechanics |
| spelling | doaj.art-b8ac65c5c927458d8e775c4cb1df28ee2022-12-21T23:14:12ZengSciendoJournal of Hydrology and Hydromechanics1338-43332021-06-0169216117010.2478/johh-2021-0004Effect of soil textural characteristics on longitudinal dispersion in saturated porous mediaMahmoodlu Mojtaba G.0Raoof Amir1van Genuchten Martinus Th.2Faculty of Agriculture and Natural Resources, Gonbad Kavous University, Gonbad Kavous, Iran.Department of Earth Sciences, Utrecht University, Utrecht, Netherlands.Department of Earth Sciences, Utrecht University, Utrecht, Netherlands.This study focuses on the effects of soil textural heterogeneity on longitudinal dispersion under saturation conditions. A series of solute transport experiments were carried out using saturated soil columns packed with two filter sands and two mixtures of these sands, having d50 values of 95, 324, 402, and 480 µm, subjected to four different steady flow rates. Values of the dispersion coefficient (D) were estimated from observed in-situ distributions of calcium chlo-ride, injected as a short nonreactive tracer pulse, at four different locations (11, 18, 25, 36 cm). Analyses of the observed distributions in terms of the standard advection-dispersion equation (ADE) showed that D increased nonlinearly with travel distance and higher Peclet numbers+. The dispersion coefficient of sand sample S1 with its largest average particle size (d50) was more affected by the average pore-water velocity than sample S4 having the smallest d50. Results revealed that for a constant velocity, D values of sample S1 were much higher than those of sample S4, which had the smallest d50. A correlation matrix of parameters controlling the dispersion coefficient showed a relatively strong positive relationship between D and the Peclet number. In contrast, almost no correlation was evident between D and porosity as well as grain size. The results obtained with the four sandy matrices were consistent and proved that the dispersion coefficient depends mainly on the particle size.https://doi.org/10.2478/johh-2021-0004solute dispersionsoil textural heterogeneitysaturated columnspeclet numberflow velocitytravel distance |
| spellingShingle | Mahmoodlu Mojtaba G. Raoof Amir van Genuchten Martinus Th. Effect of soil textural characteristics on longitudinal dispersion in saturated porous media Journal of Hydrology and Hydromechanics solute dispersion soil textural heterogeneity saturated columns peclet number flow velocity travel distance |
| title | Effect of soil textural characteristics on longitudinal dispersion in saturated porous media |
| title_full | Effect of soil textural characteristics on longitudinal dispersion in saturated porous media |
| title_fullStr | Effect of soil textural characteristics on longitudinal dispersion in saturated porous media |
| title_full_unstemmed | Effect of soil textural characteristics on longitudinal dispersion in saturated porous media |
| title_short | Effect of soil textural characteristics on longitudinal dispersion in saturated porous media |
| title_sort | effect of soil textural characteristics on longitudinal dispersion in saturated porous media |
| topic | solute dispersion soil textural heterogeneity saturated columns peclet number flow velocity travel distance |
| url | https://doi.org/10.2478/johh-2021-0004 |
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