DOI: | 10.2172/1188716
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报告号: | DOE-UDEL--07116-1
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报告题名: | The effects of Fe-oxidizing microorganisms on post-biostimulation permeability reduction and oxidative processes at the Rifle IFRC site |
作者: | Chan, Clara Sze-Yue
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出版年: | 2015
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发表日期: | 2015-07-02
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总页数: | 12
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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: | Iron oxidation, biofilms, pore-scale processes, biomineralization
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中文主题词: | 微量营养物/微量元素
; 铁
; 元素
; 金属
; 含水层
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主题词: | NUTRIENTS
; IRON
; ELEMENTS
; METALS
; AQUIFERS
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英文摘要: | Fe oxidation and biomineral formation is important in aquifers because the highly-reactive oxides can control the mobility of nutrients (e.g. phosphate, C) and metals (e.g. arsenic, uranium). Mineral formation also has the potential to affect hydrology, depending on the volume and distribution in pore spaces. In this exploratory study, we sought to understand how microbial Fe-oxidizers and their biominerals affect, and are affected by groundwater flow. As part of work at the Rifle aquifer in Colorado, we initially hypothesized that Fe-oxidizers were contributing to aquifer clogging problems associated with enhanced bioremediation. To demonstrate the presence of Fe-oxidizers in the Rifle aquifer, we enriched FeOM from groundwater samples, and isolated two novel chemolithotrophic, microaerophilic Fe-oxidizing Betaproteobacteria, Hydrogenophaga sp. P101 and Curvibacter sp. CD03. To image cells and biominerals in the context of pores, we developed a âmicro-aquifer,â a sand-filled flow-through culture chamber that allows for imaging of sediment pore space with multiphoton confocal microscopy. Fe oxide biofilms formed on sand grains, demonstrating that FeOM produce Fe oxide sand coatings. Fe coatings are common on aquifer sands, and tend to sequester contaminants; however, it has never previously been shown that microbes are responsible for their formation. In contrast to our original hypothesis, the biominerals did not clog the mini-aquifer. Instead, Fe biofilm distribution was dynamic: they grew as coatings, then periodically sloughed off sand grains, with some flocs later caught in pore throats. This has implications for physical hydrology, including pore scale architecture, and element transport. The sloughing of coatings likely prevents the biominerals from clogging wells and aquifers, at least initially. Although attached biomineral coatings sequester Fe-associated elements (e.g. P, As, C, U), when biominerals detach, these elements are transported as particles through the aquifer. Our work shows that microbial mineralization impacts in aquifers are dynamic, and that the fate and transport of biomineral-associated elements depend not only on geochemical conditions, but also physical pore-scale processes. |
URL: | http://www.osti.gov/scitech/servlets/purl/1188716
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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/41826
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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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1188716.pdf(2045KB) | 研究报告 | -- | 开放获取 | | View
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Recommended Citation: |
Chan, Clara Sze-Yue. The effects of Fe-oxidizing microorganisms on post-biostimulation permeability reduction and oxidative processes at the Rifle IFRC site. 2015-01-01.
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