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CAREER: Nanoscale Mineral Transformations During Biogeochemical Cycling and the Fate of Trace Elements and Nutrients

职业：生物地球化学循环过程中的纳米级矿物转化以及微量元素和营养素的命运

基本信息

批准号：
1056480
负责人：
Jeffrey Catalano
金额：
$ 46万
依托单位：
Washington University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2011
资助国家：
美国
起止时间：
2011-03-15 至 2017-02-28
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1056480&HistoricalAwards=false
关键词：
CAREER Nanoscale Mineral Transformations During

项目摘要

The availability and speciation of phosphate and trace elements in sediments, soils, and aquatic systems are strongly affected by biogeochemical cycling involving iron and manganese oxide minerals. These phases are commonly thought to affect the fate of such elements through passive means such as adsorption and coprecipitation. While mineral structural transformations during biogeochemical cycling and their impact on trace element and nutrient fate are well studied for the iron oxides, analogous studies are generally lacking for the Mn system. Similar to iron, environments where active biogeochemical Mn cycling is occurring often contain coexisting aqueous Mn(II) and solid Mn(III/IV) oxides. However, the lamellar structure and complex composition of these manganese minerals and the ability of Mn to undergo complex reactions, suggest that interfacial atom exchange and electron transfer reactions will be more involved for Mn oxides than for Fe oxides and likely lead to bulk structural transformations. Such chemical and structural modification of Mn oxides may have a substantial impact on the fate of trace elements and phosphate in biogeochemical systems. The primary research objective of this proposal is to expand our understanding of how atom exchange and electron transfer reactions drive nanoscale mineral transformations and affect trace element and nutrient fate. The PI?s objectives will be accomplished through a series of systematic studies that combine laboratory-based wet chemistry with advanced chemical and structural characterization of the solid bulk and surface structures and the speciation of associated trace elements and phosphate. The proposed research activities will demonstrate the operation of a new class of mineral transformations and trace element and nutrient reactions during biogeochemical cycling. This work will improve our understanding of how Fe and Mn cycling in sediments, soils, and aquatic systems affect phosphate and micronutrient availability and the fate of contaminants.The proposed research will provide potential societal benefits in the form of identifying new processes affecting contaminant fate and transport, suggesting new remediation approaches, and serving as inspiration for novel synthesis routes for battery materials. More importantly, the research described in this CAREER proposal will be leveraged to enhance a number of educational activities. These activities are organized around a theme of inquiry-based learning at the undergraduate and high school level. The proposed research activities will be actively used as learning activities for both undergraduate and high school students. These research-based educational activities will be improved and optimized in the PI?s research group, department, and for a local program providing research opportunities to high school students through the development and implementation of assessment plans. A new undergraduate course on Geology and Human Health that incorporates inquiry-based learning and inquiry-based learning modules for an aqueous geochemistry course will be developed. Course materials, pedagogical approaches, and research results will be widely disseminated through websites, blogs, and publication in scientific and education journals.

沉积物、土壤和水生系统中磷酸盐和微量元素的有效性和形态受到铁和锰氧化物矿物的地球化学循环的强烈影响。这些阶段通常被认为是影响这些元素的命运，通过被动手段，如吸附和共沉淀。虽然矿物结构的转变在地球化学循环及其对微量元素和营养物的命运的影响进行了很好的研究的铁氧化物，类似的研究一般缺乏锰系统。与铁类似，发生活性锰地球化学循环的环境通常含有共存的水溶性锰（II）和固体锰（III/IV）氧化物。然而，这些锰矿物的层状结构和复杂的组合物和Mn进行复杂反应的能力，表明界面原子交换和电子转移反应将更多地参与锰氧化物比铁氧化物，并可能导致散装结构转变。锰氧化物的这种化学和结构修饰可能对微量元素和磷酸盐在非地球化学系统中的命运产生重大影响。该提案的主要研究目标是扩大我们对原子交换和电子转移反应如何驱动纳米级矿物转化并影响微量元素和营养物质命运的理解。私家侦探？将通过一系列系统的研究来实现其目标，这些研究将联合收割机实验室湿化学与固体本体和表面结构的先进化学和结构表征以及相关微量元素和磷酸盐的形态分析相结合。拟议的研究活动将展示在地球化学循环过程中一类新的矿物转化以及微量元素和营养物反应的运作。这项工作将提高我们对沉积物，土壤和水生系统中的铁和锰循环如何影响磷酸盐和微量营养素的可用性和污染物的命运的理解，拟议的研究将提供潜在的社会效益，以确定影响污染物命运和运输的新过程，提出新的修复方法，并为电池材料的新合成路线提供灵感。更重要的是，本CAREER提案中描述的研究将被用来加强一些教育活动。这些活动是围绕本科和高中一级的探究式学习主题组织的。拟议的研究活动将积极用作本科生和高中生的学习活动。这些以研究为基础的教育活动将在PI？的研究小组，部门，并为当地计划提供研究机会，高中学生通过发展和实施评估计划。将开发一门新的地质学与人类健康本科课程，其中包括水地球化学课程的探究式学习和探究式学习单元。课程材料、教学方法和研究成果将通过网站、博客和在科学和教育期刊上发表文章广泛传播。