| DOI: | 10.2172/1168955
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| 报告号: | DOE-UCB-64189-1
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| 报告题名: | Colloid-Facilitated Transport of Cations in an Unsaturated Fractured Soil Under Transient Conditions |
| 作者: | Ryan, Joseph
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| 出版年: | 2015
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| 发表日期: | 2015-01-31
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| 国家: | 美国
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| 语种: | 英语
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| 英文关键词: | colloid
; soil
; contaminant
; transport
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| 中文主题词: | 有机物
; 下渗
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| 主题词: | ORGANIC MATTER
; INFILTRATION
|
| 英文摘要: | Rainfall experiments were conducted using intact soil cores and an instrumented soil pedon to examine the effect of physical heterogeneity and rainfall characteristics on the mobilization of colloids, organic matter, cesium, and strontium in a fractured soil. To measure the spatial variability of infiltration of colloids and contaminants, samples were collected through a 19-port grid placed below the soil core in laboratory study and in 27 samplers at multiple depths in the soil pedon in the field study. Cesium and strontium were applied to the soil cores and the soil pedon prior to mobilization experiments. Rainwater solutions of multiple ionic strengths and organic matter concentrations were applied to the soil cores and soil pedon to mobilize in situ colloids, cesium, and strontium. The mobilization of colloids and metal cations occurred through preferential flow paths in the soil cores. Compared to steady rainfall, greater amounts of colloids were mobilized during rainfall interrupted by pauses, which indicates that the supply of colloids to be mobilized was replenished during the pauses. A maximum in the amount of mobilized colloids were mobilized during a rainfall following a pause of 2.5 d. Pauses of shorter or longer duration resulted in less colloid mobilization. Freeze-thaw cycles, a transient condition in winter, enhanced colloid mobilization and colloid-facilitated transport of cesium and strontium in the soil cores. The exchange of solutes between the soil matrix and macropores caused a hysteretic mobilization of colloids, cesium, and strontium during changes in ionic strength. Colloid-facilitated mobilization of cesium and strontium was important at low ionic strength in fractures where slow flow allowed greater exchange of flow between the fractures and the surrounding matrix. The release of cesium and strontium by cation exchange occurred at high ionic strength in fractures where there is a little exchange of pore water with the surrounding matrix. The results of the field experiment suggested that ion exchange, and not organic matter- or colloid-facilitated transport, was the dominant mechanism for mobilization of cesium and strontium through the macropores of the fractured soil. |
| URL: | http://www.osti.gov/scitech/servlets/purl/1168955
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| Citation statistics: |
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| 资源类型: | 研究报告
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/41973
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| Appears in Collections: | 过去全球变化的重建
影响、适应和脆弱性
科学计划与规划
气候变化与战略
全球变化的国际研究计划
气候减缓与适应
气候变化事实与影响
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| File Name/ File Size |
Content Type |
Version |
Access |
License |
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| 1168955.doc（7693KB） | 研究报告 | -- | 开放获取 | | View
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| Recommended Citation: | |
Ryan, Joseph. Colloid-Facilitated Transport of Cations in an Unsaturated Fractured Soil Under Transient Conditions. 2015-01-01.
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