Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing Process
To remove contaminants from a layered heterogeneous porous system where the flow direction is parallel to the horizontal layering, the flushing front may advance faster in one layer than the other, resulting in a significant vertical concentration gradient across the layer interface. This gradient l...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/15/18/3292 |
| _version_ | 1797576338261934080 |
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| author | Zehao Chen Hongbin Zhan |
| author_facet | Zehao Chen Hongbin Zhan |
| author_sort | Zehao Chen |
| collection | DOAJ |
| description | To remove contaminants from a layered heterogeneous porous system where the flow direction is parallel to the horizontal layering, the flushing front may advance faster in one layer than the other, resulting in a significant vertical concentration gradient across the layer interface. This gradient leads to mass exchange between the layers due to the vertical dispersive transport. Such a mass exchange phenomenon can greatly alter the mass (and heat if the temperature is a concern) distribution in a multi-layer porous media system but has never been investigated before in a quantitative manner. In this study, high-resolution finite-element numerical models have been employed to investigate how transport properties affect contaminant transport during flushing, using a two-layer system as an example. The results showed that the porosity and retardation factor play similar roles in affecting mass flux across the interface. Increasing the porosity (or retardation factor) of one layer with a faster flushing velocity would decrease the total mass flux across the interface of the layers, while increasing the porosity (or retardation factor) of the layer with a slower flushing velocity played an adverse influence. Furthermore, increasing the transverse dispersivity of any layer increased the mass flux across the interface of the two layers. However, changes in the transverse dispersivity did not affect the spatial range (or gap along the flow direction) in which significant vertical mass flux occurs. This study has important implications for managing contaminant remediation in layered aquifers. |
| first_indexed | 2024-03-10T21:51:47Z |
| format | Article |
| id | doaj.art-ae59b17fab3b408cb346775a90ab1e26 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T21:51:47Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
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| series | Water |
| spelling | doaj.art-ae59b17fab3b408cb346775a90ab1e262023-11-19T13:26:33ZengMDPI AGWater2073-44412023-09-011518329210.3390/w15183292Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing ProcessZehao Chen0Hongbin Zhan1Water Management and Hydrological Science, Texas A&M University, College Station, TX 77843-3115, USAWater Management and Hydrological Science, Texas A&M University, College Station, TX 77843-3115, USATo remove contaminants from a layered heterogeneous porous system where the flow direction is parallel to the horizontal layering, the flushing front may advance faster in one layer than the other, resulting in a significant vertical concentration gradient across the layer interface. This gradient leads to mass exchange between the layers due to the vertical dispersive transport. Such a mass exchange phenomenon can greatly alter the mass (and heat if the temperature is a concern) distribution in a multi-layer porous media system but has never been investigated before in a quantitative manner. In this study, high-resolution finite-element numerical models have been employed to investigate how transport properties affect contaminant transport during flushing, using a two-layer system as an example. The results showed that the porosity and retardation factor play similar roles in affecting mass flux across the interface. Increasing the porosity (or retardation factor) of one layer with a faster flushing velocity would decrease the total mass flux across the interface of the layers, while increasing the porosity (or retardation factor) of the layer with a slower flushing velocity played an adverse influence. Furthermore, increasing the transverse dispersivity of any layer increased the mass flux across the interface of the two layers. However, changes in the transverse dispersivity did not affect the spatial range (or gap along the flow direction) in which significant vertical mass flux occurs. This study has important implications for managing contaminant remediation in layered aquifers.https://www.mdpi.com/2073-4441/15/18/3292flushinglayered heterogeneous mediamass fluxadvection-dispersion equation |
| spellingShingle | Zehao Chen Hongbin Zhan Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing Process Water flushing layered heterogeneous media mass flux advection-dispersion equation |
| title | Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing Process |
| title_full | Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing Process |
| title_fullStr | Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing Process |
| title_full_unstemmed | Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing Process |
| title_short | Universal Relationship between Mass Flux and Properties of Layered Heterogeneity on the Contaminant-Flushing Process |
| title_sort | universal relationship between mass flux and properties of layered heterogeneity on the contaminant flushing process |
| topic | flushing layered heterogeneous media mass flux advection-dispersion equation |
| url | https://www.mdpi.com/2073-4441/15/18/3292 |
| work_keys_str_mv | AT zehaochen universalrelationshipbetweenmassfluxandpropertiesoflayeredheterogeneityonthecontaminantflushingprocess AT hongbinzhan universalrelationshipbetweenmassfluxandpropertiesoflayeredheterogeneityonthecontaminantflushingprocess |