The effects of Fe-oxidizing microorganisms on post-biostimulation permeability reduction and oxidative processes at the Rifle IFRC site

doi:10.2172/1188716

GSTDTAP > 地球科学

DOI	10.2172/1188716
报告编号	DOE-UDEL--07116-1
来源ID	OSTI ID: 1188716
	The effects of Fe-oxidizing microorganisms on post-biostimulation permeability reduction and oxidative processes at the Rifle IFRC site
	Chan, Clara Sze-Yue
	2015-07-02
出版年	2015
页数	12
语种	英语
国家	美国
领域	地球科学
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.
英文关键词	Iron oxidation, biofilms, pore-scale processes, biomineralization
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来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/7063
专题	地球科学
推荐引用方式 GB/T 7714	Chan, Clara Sze-Yue. The effects of Fe-oxidizing microorganisms on post-biostimulation permeability reduction and oxidative processes at the Rifle IFRC site,2015.