Using molecular-scale approaches to understand soil chemical processes

使用分子尺度方法了解土壤化学过程

• 批准号: 261432-2013
• 负责人: Peak, John
• 金额: $ 3.5万
• 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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=634238
• 关键词: Using; molecular; scale; approaches; understand

Chemical reactions in soils often control the mobility, toxicity, and availability of nutrients and contaminants in natural systems. Understanding precisely how soil chemical reactions proceed is therefore vital in assessing environmental fate. A recurring theme in the study of soil chemistry is that the most reactive soil surfaces are not the bulk crystalline minerals that make up 90-95% of soil, but instead are the highly reactive poorly-crystalline nano-minerals that form coatings on larger soil particles. The objective of this research is to better understand the factors that lead to the persistence and reactivity of two of these phases (ferrihydrite and dicalcium phosphates) that are important for both environmental and agronomic reasons. To accomplish this objective, we will use synchrotron-based X-ray Absorption Spectroscopy (XAS) at the Canadian Light Source. This method provides direct measurement of both the nano-mineral structure and details of how contaminants bond to those those minerals under hydrated conditions. This research in this program will improve the fundamental understanding of soil chemistry and the results will be important for agriculture in both temperate and tropical climates, environmental geochemistry and contaminant chemistry. This project also explores relationships between soil chemical processes with metal-organic frameworks; this could lead to major advances in our understanding of soil organic matter. Finally, the EEMS technique will be useful for a wide range of natural resource-related problems, including oil sands extractions, evaluating mining ores and tailings, and mineral exploration.

土壤中的化学反应通常控制自然系统中养分和污染物的活动性，毒性和可用性。因此，确切了解土壤化学反应如何进行对于评估环境命运至关重要。土壤化学研究中的一个反复出现的主题是，最具反应性的土壤表面不是占土壤90-95％的批量晶体矿物质，而是高度反应性较差的晶状体纳米矿物质，它们在较大的土壤颗粒上形成涂料。这项研究的目的是更好地理解导致这两个阶段（亚铁岩和磷酸二硫酸二硫酸二硫酸盐）的持久性和反应性的因素，这些因素出于环境和农艺原因都很重要。为了实现这一目标，我们将使用加拿大光源的基于同步加速器的X射线吸收光谱（XAS）。该方法提供了纳米矿物结构的直接测量，以及在水合条件下与这些矿物质粘合的污染物如何结合的细节。该计划中的这项研究将改善对土壤化学的基本理解，结果对于温带和热带气候，环境地球化学和污染物化学的农业都将很重要。该项目还探讨了土壤化学过程与金属有机框架之间的关系。这可能会导致我们对土壤有机物的理解的重大进展。最后，EEMS技术将对多种与自然资源相关的问题有用，包括油砂提取物，评估采矿矿石和尾矿以及矿物质勘探。