Nano-Earth sciences: Understanding environmental processes at the nano-scale

加拿大的经济在很大程度上依赖自然资源，包括矿藏。矿藏的开采导致了尾矿库的建设、冶炼厂的微粒物质排放和采矿活动期间产生的粉尘。拟议的研究将提供有关受污染土壤和沉积物、废弃尾矿和利用富有机质土壤回收的尾矿中金属和金属（固体）命运的基本知识。拟议的研究将专门研究纳米尺度（1-100纳米）的地球和环境过程。这种规模的过程通常控制着土壤、尾矿、沉积物和水中含金属和含金属污染物的命运。例如，纳米尺度上与环境有关的过程包括污染物在矿物表面、有机物和纳米颗粒上的吸附，含污染物纳米颗粒在土壤、沉积物和尾矿中的运输，以及含污染物纳米颗粒的形成、团聚、附着和释放。这些纳米级过程的一个重要方面是矿物和有机物表面与溶解在溶液中或附着或合并到纳米颗粒中的污染物的相互作用。虽然以前的污染物与矿物和有机物表面相互作用的模型假设这两种成分的表面在组成上是相对均匀的，并且这些材料上和内部的环境条件是相对恒定的；最近的研究表明，情况并非如此：矿物表面和有机物已经发生了化学变化，这些变化实体中的环境条件在纳米尺度上有所不同。因此，矿物表面和有机物远比以前认为的要复杂。拟议的研究将探索改变的矿物表面和有机物质（如根、细菌和植物和树木的凋落物）中污染物的相互作用。这项研究使用了加拿大和美国专业实验室的仪器，这些仪器可以在纳米尺度上可视化化学过程。

Canada's economy depends strongly on natural resources including mineral deposits. Mining of mineral deposits has led to the construction of tailings impoundments, particulate matter emissions from smelters, and generation of dust during mining activities. The proposed studies will provide fundamental knowledge on the fate of metals and metal(loids) in contaminated soils and sediments, abandoned tailings and tailings reclaimed using organic-rich soils. The proposed study will specifically examine Earth and Environmental processes at the nano scale (1-100 nm). Processes at this scale commonly control the fate of metal- and metalloid-bearing contaminants in soils, tailings, sediments and water. Environmentally relevant processes at the nano-scale are for example adsorption of contaminants on mineral surfaces, organic matter and nanoparticles, the transport of contaminant-bearing nanoparticles within soils, sediments and tailings and the formation, agglomeration, attachment and release of contaminant-bearing nanoparticles. An important aspect of these nano-scale processes is the interaction of surfaces of minerals and organic matter with contaminants dissolved in solution or attached or incorporated into nanoparticles. Although previous models of the interaction of contaminants with surfaces of minerals and organic matter assumed that the surfaces of both constituents are relatively homogeneous in composition and that the environmental conditions on and within these materials are relatively constant; recent studies show that this is not the case: mineral surfaces and organic matter have been chemically altered and the environmental conditions in these altered entities vary on the nano-scale. Hence, mineral surfaces and organic matter are far more complex than previously assumed. The proposed study will explore the interaction of contaminants within altered mineral surfaces and organic matter such as roots, bacteria and litter from plants and trees. This study uses instruments in specialized laboratories in Canada and the USA that allow the visualization of chemical processes on the nano-scale.