Organic Coatings on Sedimentary Mineral Grains

沉积矿物颗粒上的有机涂层

• 批准号: 9633230
• 负责人: Lawrence Mayer
• 金额: $ 40.71万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-10-01 至 2003-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9633230&HistoricalAwards=false
• 关键词: Organic; Coatings; Sedimentary; Mineral; Grains

9633230 Mayer A pore protection hypothesis will be tested, provide a mechanistic basis for the observed patterns of organic carbon. Relationships between organic matter and mineral surfaces will be developed by: (1) Assessing the extent of organic matter coverage on mineral grains. Is organic carbon localized in small areas or is it widely dispersed? Wide dispersal implies that major fraction must reside in small pores. This question will be tested by completing development of a promising new method based on the of gas adsorption onto mineral surfaces. Completion work will focus on the nature of naked mineral surfaces, identifying variations that derive from mineralogy, microtopography, and source area; (2) Determining if natural organic matter resides preferentially inside small mesopores, by careful examination of the effects of removal of organic coatings on the size distribution of pores. This test will also involve the reverse process of adding artificial organic coatings to uncoated mineral grains, providing insight into the localization and mechanism of organic matter sorption. (3) Testing if these small mesopores on mineral grains can indeed exclude hydrolytic enzymes, by performing a series of size- exclusion and adsorption experiments. These approaches will be carried out on a wide variety of sediments from around the world. In addition to testing the pore hypothesis, results from this project will have important implications for carbon cycling, mineral-water interactions, and pollutant cycling.

9633230梅耶尔将检验孔隙保护假说，为观察到的有机碳模式提供机制基础。有机质和矿物表面之间的关系将通过：(1)评估有机质在矿物颗粒上的覆盖程度。有机碳是集中在小区域，还是广泛分布？广泛分散意味着大部分组分必须存在于较小的孔隙中。这个问题将通过完成一种有前景的新方法的开发来测试，该方法基于气体在矿物表面的吸附。完成工作将侧重于裸露矿物表面的性质，确定源自矿物学、微地形和物源区的变化；(2)通过仔细检查去除有机涂层对孔隙大小分布的影响，确定天然有机物是否优先驻留在小的中孔内。这项测试还将涉及在未包覆的矿物颗粒中添加人造有机涂层的反向过程，从而深入了解有机物吸附的局部化和机理。(3)通过一系列的尺寸排除和吸附实验，测试矿物颗粒上的这些小中孔是否真的能排除水解酶。这些方法将在世界各地的各种沉积物上进行。除了验证气孔假说之外，该项目的结果还将对碳循环、矿泉水相互作用和污染物循环产生重要影响。