Biogeochemical and mineralogical transformation of biogenic iron-rich minerals under environmental conditions

环境条件下生物富铁矿物的生物地球化学和矿物学转化

• 批准号: 203346-2011
• 负责人: Fortin, Danielle
• 金额: $ 3.64万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569934
• 关键词: Biogeochemical; mineralogical; transformation; biogenic; iron

Biogenic minerals are minerals that form in close association with microorganisms. In natural environments, iron-rich minerals are often associated with bacteria using the oxidation of iron as a source of energy, which leads to the precipitation of very small iron oxide particles. Given their small size and their inherent large surface area, biogenic iron oxides can sequester large quantities of soluble contaminants, which makes them efficient sorbents in natural remediation strategies where soluble metals are the main contaminants. However, the long term transformation of these minerals is poorly constrained. Do they remain amorphous? Do they transform into more crystalline oxides and re-lease their sorbed contaminants? Do they undergo reduction in anoxic environments? The present proposal is designed to answer these questions by investigating the long term biogeochemical and mineral transformation of various biogenic iron minerals under environmentally relevant conditions. Four graduate students (2 M.Sc. and 2 Ph.D.) will tackle the above questions by performing short and long term ageing experiments and using state-of-the-art characterization techniques, such as electron microscopy, micro X-ray diffraction and synchrotron-based analyses. It is expected that the results will provide valuable information for the potential use of biogenic iron minerals in remediation strategies.

生物矿物质是与微生物密切相关的矿物质。在自然环境中，富含铁的矿物质通常与使用铁的氧化作为能量来源的细菌有关，这导致非常小的氧化铁颗粒沉淀。由于其小尺寸和固有的大表面积，生物氧化铁可以螯合大量的可溶性污染物，这使得它们在可溶性金属是主要污染物的自然修复策略中成为有效的吸附剂。然而，这些矿物的长期转化受到很大限制。它们保持无定形吗？它们会转化为更多的结晶氧化物并释放它们吸附的污染物吗？它们在缺氧环境中会发生还原吗？本建议旨在回答这些问题，通过调查长期生物地球化学和矿物转化的各种生物铁矿物在环境相关条件下。4名研究生（2名硕士和2名博士）将通过进行短期和长期老化实验，并使用最先进的表征技术，如电子显微镜、微X射线衍射和同步加速器分析，来解决上述问题。预计研究结果将为生物铁矿物在修复策略中的潜在应用提供有价值的信息。