| DOI: | 10.2172/1214871
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| 报告号: | SC0006681
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| 报告题名: | Constraining the role of iron in environmental nitrogen transformations. Dual stable isotope systematics of abiotic NO<sub>2</sub>- reduction by Fe(II) and its production of N<sub>2</sub>O |
| 作者: | Johnston, David; Wankel, Scott David; Buchwald, Carolyn; Hansel, Colleen
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| 出版年: | 2015
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| 发表日期: | 2015-09-16
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| 总页数: | 43
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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: | nitrogen
; iron
; redox
; stable isotope
; nitrous oxide
; nitrite
|
| 中文主题词: | 氮
; 亚硝酸盐
; 一氧化二氮/氧化亚氮
; PH
; 放射性核素
; 铁
; PH值
|
| 主题词: | NITROGEN
; NITRITE
; NITROUS OXIDE
; PH
; RADIONUCLIDES
; IRON
|
| 英文摘要: | Redox reactions involving nitrogen and iron have been shown to have important implications for mobilization of priority contaminants. Thus, an understanding of the linkages between their biogeochemical cycling is critical for predicting subsurface mobilization of radionuclides such as uranium. Despite mounting evidence for biogeochemical interactions between iron and nitrogen, our understanding of their environmental importance remains limited. Here we present an investigation of abiotic nitrite (NO2-) reduction by Fe(II) or âchemodenitrification,â and its relevance to the production of nitrous oxide (N2O), specifically focusing on dual (N and O) isotope systematics under a variety of environmentally relevant conditions. We observe a range of kinetic isotope effects that are regulated by reaction rates, with faster rates at higher pH (~8), higher concentrations of Fe(II) and in the presence of mineral surfaces. A clear non-linear relationship between rate constant and kinetic isotope effects of NO2- reduction was evident (with larger isotope effects at slower rates) and is interpreted as reflecting the dynamics of Fe(II)-N reaction intermediates. N and O isotopic composition of product N2O also suggests a complex network of parallel and/or competing pathways. Our findings suggest that NO2- reduction by Fe(II) may represent an important abiotic source of environmental N2O, especially in iron-rich environments experiencing dynamic redox variations. This study provides a multi-compound, multi-isotope framework for evaluating the environmental occurrence of abiotic NO2- reduction and N2O formation, helping future studies constrain the relative roles of abiotic and biological N2O production pathways. |
| URL: | http://www.osti.gov/scitech/servlets/purl/1214871
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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/41767
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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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| 1214871.pdf（1244KB） | 研究报告 | -- | 开放获取 | | View
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| Recommended Citation: | |
Johnston, David,Wankel, Scott David,Buchwald, Carolyn,et al. Constraining the role of iron in environmental nitrogen transformations. Dual stable isotope systematics of abiotic NO<sub>2</sub>- reduction by Fe(II) and its production of N<sub>2</sub>O. 2015-01-01.
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