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

加拿大经济严重依赖自然资源，包括矿藏。开采矿藏导致了尾矿库的建设，冶炼厂的颗粒物排放，以及采矿活动中产生的粉尘。拟议的研究将为金属和金属(固体)在受污染的土壤和沉积物、废弃的尾矿和利用富含有机物质的土壤再生的尾矿中的去向提供基本知识。这项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类金属的污染物的命运。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、沉积物和尾矿中的迁移，以及含污染物纳米颗粒的形成、聚集、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的污染物或附着在纳米颗粒中或结合在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定这两种组分的表面组成相对均匀，这些材料表面和内部的环境条件相对恒定；但最近的研究表明情况并非如此：矿物表面和有机物发生了化学变化，这些变化的实体中的环境条件在纳米级上变化。因此，矿物表面和有机质比之前假设的要复杂得多。这项拟议的研究将探索蚀变矿物表面的污染物与有机物(如根、细菌和植物和树木的凋落物)之间的相互作用。这项研究使用了加拿大和美国专门实验室的仪器，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.