Uptake and release of heavy metals by minerals and rock coatings

许多国家的金融财富与其资源和制造业息息相关。在加拿大，采矿材料的加工和废物处理是向环境释放重金属的关键来源。这些元素在空气、水和土壤中的积累严重影响环境的健康。因此，了解重金属在环境中的去向对于预测空气、水和土壤中污染物的存在至关重要。预测性理解需要关于特定元素所含物质与环境相互作用的知识，一旦元素被释放，它与地质和屏障材料的相互作用。我的研究主要集中在矿物和岩石矿物涂层对重金属的释放和吸收的表征上。在我正在进行的研究中，我研究了通过溶解次生铀矿物释放铀的情况，当核废料与富氧溶液接触时，这种情况很可能会发生。我这部分研究的短期目标是对次生铀矿物的溶解性质(特征和动力学)与其结构和溶液中元素的晶体化学性质之间的一般了解。我未来研究的主要部分将是涂层和蚀变相对重金属吸收的表征。矿物对重金属的吸收主要是利用未改变的表面来研究的。然而，暴露在大气中的矿物表面可能会被涂层改变或覆盖，因此它们与重金属的相互作用取决于靠近“母”矿物的蚀变层或蚀变相的组成和结构特征。这些检查将包括硅酸盐矿物蚀变层吸收重金属的实验室实验。此外，还将研究萨德伯里周围的尾矿和酸性土壤以及墨西哥埃利奥特湖和Pena Blanca的铀矿床中的涂层和蚀变相。铀矿床的研究结果将使人们更好地了解富含二氧化硅岩性的尾矿或核废料储存库中铀的动员情况。

The financial wealth of many countries is tied to their resources and manufacturing industries. In Canada, the processing of mining materials and waste disposal are key sources of the release of heavy metals into the environment. Accumulations of these elements in air, water and soils have a severe impact on the health of the environment. Therefore, understanding the fate of a heavy metal in the environment is critical to predict the presence of contaminants in air, water and soil. Predictive understanding requires knowledge regarding the interaction of a specific element-bearing material with the environment and once the element is released, its interaction with geological and barrier materials. My research focuses on the characterization of the release and uptake of heavy metals by minerals and coatings on rocks and minerals. In my ongoing research, I examine the release of Uranium via the dissolution of secondary uranium minerals, a scenario that would likely occur when nuclear waste comes in contact with Oxygen-rich solutions. A short-term goal of this part of my research is a general understanding between the dissolution properties of a secondary uranium mineral (features and kinetic) and its structure and the crystal-chemical properties of the elements in solution. The major part of my future research will be the characterization of the uptake of heavy metals by coatings and alteration phases. The uptake of heavy metals by minerals was dominantly studied using non-altered surfaces. However, mineral surfaces exposed to the atmosphere can be altered or covered by coatings and their interaction with heavy metal thus depends on the composition and structural features of alteration layers or alteration phases in proximity to the "parent" minerals. These examinations will include laboratory experiments on the uptake of heavy metals by alteration layers on silicate minerals. Furthermore, coatings and alteration phases will be studied in mine tailings and acidic soils around Sudbury and in the U-deposits of Elliot Lake and Pena Blanca, Mexico. The results from the studies at the U-deposits will give a better understanding on the mobilization of Uranium in mine tailings or nuclear waste repositories that are hosted in silica-rich lithologies.