| DOI: | 10.2172/1240154
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| 报告号: | DOE-TAMU--0006823
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| 报告题名: | Importance of Microbial Activity On Groundwater Iodate and Organo-Iodine Speciation and Mobility At Two DOE Sites |
| 作者: | Santschi, Peter H.; Xu, Chen; Schwehr, Kathleen A.; Kaplan, Daniel I.; Yeager, Chris M.
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| 出版年: | 2016
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| 发表日期: | 2016-03-01
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| 总页数: | 2
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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: | Iodine-129
; Iodine Speciation
; Iodine Isotope Ratios
; Role of Natural Organic Matter
; Mobility
; Savannah River Site
; Hanford Site
; Fukushima Site
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| 中文主题词: | 有机物
; 冰上通道
; PH
; 水道
; PH值
|
| 主题词: | ORGANIC MATTER
; LEADS
; PH
|
| 英文摘要: | Iodine (I) occurs in multiple oxidation states in aquatic systems in the form of organic and inorganic species (iodide and iodate). This fact leads to complex biogeochemical cycling of Iodine and its long-lived isotope, 129I, a major by-product of nuclear fission. Results from our newly developed, sensitive and rapid method for speciated isotopic ratios (129I/127I) via GC-MS, which compare favorably with Accelerator Mass Spectroscopy, demonstrate that the mobility of 129I species greatly depends on the type of I species and its concentration, pH, and sediment redox state. At ambient concentrations (~107 M), I- and IO-3 are significantly retarded by sorption to mineral surfaces and covalent binding to aromatic moieties in natural organic matter (NOM), even when NOM is present at low concentrations such as occur at Hanford. At concentrations traditionally examined in sorption studies (⼠10-4 M), I- travels along with the water. Iodate removal can also occur through incorporation into CaCO3 crystal lattice, e.g., at the Hanford Site. Removal of iodine from the groundwater through interaction with NOM is complicated by the release of mobile organo-I species, as was observed at SRS and Hanford. A small fraction of NOM that is bound to iodine can behave as a mobile organo-I source, a process that we were able to numerically simulate. Field and laboratory studies evaluating the cause for steady increases in 129I concentrations (up to 1000 pCi L-1) emanating from radiological basins at SRS indicate that an increase of 0.7 pH units in groundwater over 17 years can account for the observed increased groundwater 129I concentrations. Bacteria from a 129I-contaminated aerobic aquifer at the F-area of SRS can accumulate I- at environmentally relevant concentrations (10-7 M), and enzymatically oxidize I-, which together with microbially produced MnO2 and superoxide or organic acids can significantly contribute to organo-iodine formation. |
| URL: | http://www.osti.gov/scitech/servlets/purl/1240154
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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/42240
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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 |
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| 1240154.pdf（96KB） | 研究报告 | -- | 开放获取 | | View
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| Recommended Citation: | |
Santschi, Peter H.,Xu, Chen,Schwehr, Kathleen A.,et al. Importance of Microbial Activity On Groundwater Iodate and Organo-Iodine Speciation and Mobility At Two DOE Sites. 2016-01-01.
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