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, Derek
• 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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=594560
• 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.

土壤中的化学反应通常控制着自然系统中营养物质和污染物的流动性、毒性和可用性。因此，准确了解土壤化学反应是如何进行的，对于评估环境命运至关重要。土壤化学研究中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%的大块晶体矿物质，而是在较大土壤颗粒上形成涂层的高反应性低结晶纳米矿物质。本研究的目的是更好地了解这些阶段（水铁矿和磷酸二钙），这是重要的环境和农艺原因的持久性和反应性的因素。为了实现这一目标，我们将在加拿大光源使用基于同步加速器的X射线吸收光谱（XAS）。这种方法提供了直接测量纳米矿物结构和污染物如何在水合条件下与这些矿物结合的细节。