Metal-mineral interactions in dynamic redox environments

动态氧化还原环境中的金属-矿物相互作用

• 批准号: RGPIN-2020-05172
• 负责人: Lindsay, Matthew
• 金额: $ 3.13万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=740430
• 关键词: Metal; mineral; interactions; dynamic; redox

Minerals control the distribution, transport, and bioavailability of metals in soils, sediments, and aquifers. Understanding interactions between metals and minerals is therefore critical because many metals support important biological functions but are potentially hazardous at higher concentrations. Iron (oxyhydr)oxide minerals are particularly important due to their high capacity for metal uptake and common occurrence near Earth's surface. These minerals are relatively stable in the presence of oxygen; however, declining oxygen availability can lead to reactions that decrease their stability and affect metal retention. These reductive reactions have implications for biogeochemical metal cycling on a global scale. The overall research objective is to determine how changing environmental conditions affect the stability of iron (oxyhydr)oxide minerals and the retention of associated metals. This research will examine interactions of the metals molybdenum, tungsten, and vanadium with the iron (oxyhydr)oxide minerals ferrihydrite, lepidocrocite, and goethite. These transition metals form important metalloenzymes, are emerging environmental contaminants, and readily partition onto surfaces of these minerals. Research experiments will examine complexities of metal uptake onto iron (oxyhydr)oxide phases over a range of geochemical conditions. Subsequent experiments will examine metal retention during mineral transformation reactions promoted by addition of ferrous iron or hydrogen sulfide in the absence of oxygen. Final experiments will assess longer-term metal retention under varied redox conditions relevant to environmental conditions on Earth. This research will support training at the undergraduate, graduate and postdoctoral levels. Results will advance understanding of relationships between redox conditions, mineral stability and the distribution, transport and bioavailability of molybdenum, tungsten and vanadium near Earth' surface. This information may inform interpretations of their distribution in the sedimentary rock record, which can offer insight into productivity and redox conditions over geologic time. These metals are also emerging environmental contaminants associated with anthropogenic activities including mining and mineral processing. Therefore, results may also support development of new strategies for mine waste management and reclamation.

矿物控制着土壤、沉积物和含水层中金属的分布、迁移和生物有效性。因此，了解金属和矿物质之间的相互作用至关重要，因为许多金属支持重要的生物功能，但在更高的浓度下具有潜在的危险。铁（氧氢）氧化物矿物是特别重要的，因为它们对金属的吸收能力很高，并且在地球表面附近常见。这些矿物质在氧气存在下相对稳定;然而，氧气可用性下降可能导致降低其稳定性并影响金属保留的反应。这些还原反应对全球范围内的地球化学金属循环有影响。总体研究目标是确定不断变化的环境条件如何影响氧化铁矿物的稳定性和相关金属的保留。本研究将探讨金属钼，钨，钒与铁（氧）氧化物矿物水铁矿，纤铁矿，针铁矿的相互作用。这些过渡金属形成重要的金属酶，是新兴的环境污染物，并且容易分配到这些矿物的表面上。研究实验将检查在一系列地球化学条件下，铁（氢氧化物）氧化物相吸收金属的复杂性。随后的实验将研究在无氧条件下加入亚铁或硫化氢促进矿物转化反应过程中的金属保留。最后的实验将评估在与地球环境条件相关的各种氧化还原条件下的长期金属保留。 这项研究将支持本科生、研究生和博士后的培训。研究结果将促进对氧化还原条件、矿物稳定性与钼、钨和钒在地球表面的分布、迁移和生物有效性之间关系的理解。这些信息可以解释它们在沉积岩记录中的分布，从而可以深入了解地质时期的生产力和氧化还原条件。这些金属也是与采矿和矿物加工等人类活动有关的新出现的环境污染物。因此，研究结果也可能支持矿山废物管理和回收的新战略的发展。