CAREER: The Importance of Iron in the Remineralization of Organic Matter in Estuarine and Continental Shelf Sediments

职业：铁在河口和大陆架沉积物有机物再矿化中的重要性

• 批准号: 0239376
• 负责人: Martial Taillefert
• 金额: $ 49.92万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0239376&HistoricalAwards=false
• 关键词: CAREER; Importance; Iron; Remineralization; Organic

ABSTRACTOCE-0239376The fate and transformation of organic carbon in coastal and marine sediments is intrinsic to understanding the carbon cycle and its influences on global climate change. The objective of the proposed research by the PI was to examine the mechanisms of natural organic matter (NOM) transformation in estuarine and continental shelf sediments through in-situ technology and mathematical modeling. The research is based on the following two hypotheses: 1) microbial Fe(III) reduction accounts for a significant portion of NOM remineralization in the target regions, and 2) sufficient oxygen is supplied through bioturbation to recycle Fe(OH)3 efficiently for NOM remineralization. The PI proposed to construct a lander system with a benthic chamber, a micromanipulator and voltammetric microelectrodes to obtain in situ benthic flux data and microprofiles. This in situ data combined with sulfate reduction rates, solid phase and porewater data from sediment cores, and results from reactor experiments would be used to calculate NOM remineralization rates. The PI then proposed to develop a 3-D diagenetic model to predict NOM remineralization in continental shelf and estuarine sediments.Incorporating chemists and engineers into the chemical oceanography field was one of four objectives of the educational component. The PI proposed to involve students in these fields in the development of the lander system and the modeling effort. Additionally, a high school teacher would conduct a research project in the PI's laboratory during the summer as part of an existing program at GIT. The third component entailed development of a laboratory component of an existing Geochemistry course. This laboratory component would include cruises on the R/V Savannah to deploy the lander system and involve the students in the field and laboratory efforts of the proposed research. The fourth component consisted of a student exchange program involving GIT, Skidaway Institute of Oceanography, and European partners.

海岸和海洋沉积物中有机碳的命运和转化是理解碳循环及其对全球气候变化影响的内在因素。 PI拟议研究的目的是通过原位技术和数学建模来研究河口和大陆架沉积物中天然有机质（NOM）转化的机制。 本研究基于以下两个假设：1）微生物Fe（III）还原占目标区域NOM矿化的重要部分; 2）通过生物扰动提供足够的氧气以有效地回收Fe（OH）3用于NOM矿化。 PI提议建造一个着陆器系统，其中包括一个底栖室、一个显微操作器和伏安微电极，以获得现场底栖通量数据和微剖面。 该原位数据结合硫酸盐还原速率、沉积物岩心的固相和孔隙水数据以及反应器实验结果将用于计算NOM矿化速率。 PI然后建议开发一个三维成岩模型来预测大陆架和河口沉积物中的NOM矿化。将化学家和工程师引入化学海洋学领域是教育部分的四个目标之一。 PI建议让这些领域的学生参与着陆器系统的开发和建模工作。 此外，一名高中教师将在夏季在PI的实验室进行一项研究项目，作为GIT现有项目的一部分。 第三个组成部分是在现有的地球化学课程中增加实验室部分。 这一实验室组成部分将包括在R/V萨凡纳上进行巡航，以部署着陆器系统，并使学生参与拟议研究的实地和实验室工作。 第四部分包括一个学生交流计划，涉及GIT，Skidaway海洋学研究所和欧洲合作伙伴。