| 项目编号: | 1529830
|
| 项目名称: | Collaborative Research: Selenium redox reactions and isotope ratios: The role of microbial and abiotic Selenium oxidation |
| 作者: | Thomas Johnson
|
| 承担单位: | University of Illinois at Urbana-Champaign
|
| 批准年: | 2014
|
| 开始日期: | 2015-09-01
|
| 结束日期: | 2018-08-31
|
| 资助金额: | USD86032
|
| 资助来源: | US-NSF
|
| 项目类别: | Standard Grant
|
| 国家: | US
|
| 语种: | 英语
|
| 特色学科分类: | Geosciences - Earth Sciences
|
| 英文关键词: | se oxidation
; se
; selenium
; oxidation
; chemical reaction
; abiotic oxidation
; key chemical reaction
; reaction rate
; 82se/76se ratio
|
| 英文摘要: | Selenium (Se) is an essential micronutrient, a potential environmental contaminant, and an indicator of chemical reactions involving oxidation and reduction, in both present and past environmental systems. Chemical and biological processes control the mobility and environmental impact of Se. Although Se oxidation is an important Se-mobilizing process, our understanding of this process is limited. Additionally, although measurements of variations in Se stable isotope abundances (82Se/76Se ratios) provide a powerful new way to study key chemical reactions involving Se in modern and ancient environments, poor understanding of Se stable isotope shifts caused by Se oxidation limits interpretation of Se isotope data. Therefore, this project will investigate stable Se isotope variation caused by oxidation as a means to achieve a robust understanding of Se oxidation in the environment. Investigators will train one postdoctoral fellow, two doctoral students, and 6-8 undergraduate students per year through programs that target underrepresented students. The societal benefits of this project include communications with the concerned governmental agencies to enable better assessments of Se fate linked to human nutritional adequacy, toxic thresholds and the fundamental understanding of Se in the earth system.
The scope of the project is to integrate stable isotope geochemistry and microbiology to gain an improved understanding of biotic and abiotic Se oxidation. The specific objectives are to (1) demonstrate that microbial Se oxidation supports chemoautotrophic growth, (2) determine the magnitude of Se isotopic fractionation caused by microbial and abiotic oxidation of reduced Se-species, and (3) examine oxidation of Se in natural soil/sediment matrices to determine how the laboratory-derived fractionation factors will apply in natural environments. Controlled laboratory experiments will be conducted to determine reaction rates and Se isotope fractionation during microbial and abiotic Se oxidation. Slurry experiments with soils and sediments of two different field sites will provide complementary understanding of Se oxidation in natural samples under well-defined conditions. By establishing a link between Se oxidation and Se isotope fractionation, the results will open new avenues for studies of Se cycling and the fate of Se as a micronutrient and contaminant. |
| 资源类型: | 项目
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/93388
|
| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
|
|
There are no files associated with this item.
|
| Recommended Citation: | |
Thomas Johnson. Collaborative Research: Selenium redox reactions and isotope ratios: The role of microbial and abiotic Selenium oxidation. 2014-01-01.
|
|
|