Collaborative Research: Iron Incorporation into Biogenic Silica

合作研究：将铁掺入生物二氧化硅中

• 批准号: 1658181
• 负责人: Ellery Ingall
• 金额: $ 30.97万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1658181&HistoricalAwards=false
• 关键词: Collaborative; Research; Iron; Incorporation; into

Ocean research over the last several decades has increasingly shown the great importance of iron chemistry on marine biological processes. In certain areas of the ocean where iron is scarce, it can limit biological growth even though other essential nutrients like nitrogen and phosphorus are abundant. Consequently, to fully understand and quantify biological productivity in the ocean, a complete knowledge of all sources and sinks for iron is essential. The researchers funded for this project have already generated exciting preliminary data that suggest a potentially large, yet, unquantified pathway for iron removal. Diatoms, phytoplankton with shells made of silica, are shown to incorporate traces of iron into their shells, making it unavailable for rapid recycling or use by marine organisms in surface waters. Given the great abundance of diatoms in many parts of the ocean, this could represent a major, unstudied removal mechanism that regulates the concentration of iron in seawater. This research could transform current understanding of how iron is removed from the ocean, and it will impact understanding of both the chemical and biological processes involving iron in seawater. The investigator also plans outreach in K-12 schools by providing educational courses for Earth Science teachers and will support graduate student training in advanced chemical analysis and oceanography. High-resolution synchrotron-based chemical techniques will allow determination of the concentration and oxidation state of iron bound within diatom frustules. This analytical advance has created the ability for unique evaluation of iron sequestration into biogenic silica as a major pathway for iron removal from the ocean. Samples from the Pacific sector of the Southern Ocean have been collected in a previous CLIVAR field campaign and a subset of these are available for new synchrotron analysis of iron (Fe) with Near Edge X-ray Fluorescence Spectroscopy (Fe-NEXFS) and submicron scale X-ray fluorescence mapping, as well as a variety of other chemical characterizations. With these methods, the project will determine the importance of iron sequestered into biogenic silica as a new and unquantified loss term in the oceanic Fe cycle and examine the changing chemical complexes of iron during vertical transport of silica particles through the water column.

过去几十年的海洋研究越来越表明铁化学对海洋生物过程的重要性。在某些缺铁的海洋区域，即使氮和磷等其他必需营养素丰富，铁也会限制生物生长。 因此，为了充分了解和量化海洋中的生物生产力，全面了解铁的所有来源和汇至关重要。资助该项目的研究人员已经生成了令人兴奋的初步数据，这些数据表明了潜在的巨大但未量化的除铁途径。硅藻是一种外壳由二氧化硅制成的浮游植物，其外壳中含有微量的铁，使其无法快速回收或被地表水中的海洋生物使用。鉴于海洋许多地方都有大量的硅藻，这可能代表了一种未经研究的主要去除机制，可以调节海水中的铁浓度。这项研究可能会改变目前对如何从海洋中去除铁的理解，并将影响对海水中涉及铁的化学和生物过程的理解。研究人员还计划通过为地球科学教师提供教育课程来在 K-12 学校进行推广，并将支持高级化学分析和海洋学方面的研究生培训。基于高分辨率同步加速器的化学技术将能够确定硅藻壳内结合的铁的浓度和氧化态。这一分析进步创造了对生物二氧化硅中的铁固存进行独特评估的能力，作为从海洋中去除铁的主要途径。来自南大洋太平洋区域的样本已在之前的 CLIVAR 野外活动中采集，其中一部分可用于利用近边 X 射线荧光光谱 (Fe-NEXFS) 和亚微米尺度对铁 (Fe) 进行新的同步加速器分析X 射线荧光图谱以及各种其他化学表征。通过这些方法，该项目将确定生物二氧化硅中的铁作为海洋铁循环中新的、未量化的损失项的重要性，并研究二氧化硅颗粒通过水柱垂直输送过程中铁化学复合物的变化。

项目成果

Relationship between Atmospheric Aerosol Mineral Surface Area and Iron Solubility

大气气溶胶矿物表面积与铁溶解度的关系

• DOI: 10.1021/acsearthspacechem.9b00152
• 发表时间: 2019
• 期刊: ACS Earth and Space Chemistry
• 影响因子: 3.4
• 作者: McDaniel, Mary Francis;Ingall, Ellery D.;Morton, Peter L.;Castorina, Erin;Weber, Rodney J.;Shelley, Rachel U.;Landing, William M.;Longo, Amelia F.;Feng, Yan;Lai, Barry
• 通讯作者: Lai, Barry

Enhanced Iron Solubility at Low pH in Global Aerosols

• DOI: 10.3390/atmos9050201
• 发表时间: 2018-05
• 作者: E. Ingall;Yan Feng;Amelia F. Longo;B. Lai;R. Shelley;W. Landing;P. Morton;A. Nenes;N. Mihalopoulos;K. Violaki;Yuan Gao;S. Sahai;Erin Castorina