CAREER: Impacts of Incorporated Metals on Dissolution Rates of Minerals

某些有毒和放射性金属，如铅和放射性锶，当它们溶解在地表水或地下水中时，可能会引起环境和健康问题。去除或防止它们进入环境的一种方法是将它们结合到固体矿物中，在那里它们可以被固定并长期储存。然而，被结合的金属会直接影响这些矿物的溶解速度，从而将污染物释放回环境中。目前还不清楚哪些金属最有可能增加或降低这些矿物的溶解速度，但这些信息将有助于制定更有效的补救战略。拟议的项目将确定被纳入的金属如何影响矿物溶解速度，并开发一个模型，以更好地预测在环境修复期间沉淀的矿物的稳定性和寿命。该项目还将通过与皇后学院和两所当地社区学院的学生开展合作研究体验和大学间系列研讨会，支持、培训和促进留住不同群体的本科生。该项目的研究目标是确定与其纯终端成员相相比，驱动矿物与所结合金属的溶解差异的分子尺度机制。虽然矿物相的热力学溶解度可以用来确定溶解的可能性，但溶解速度也同样重要，因为溶解度并不总是与反应速度相关。溶解速度可以用动力学模型来预测，但这些模型通常是针对纯矿物相而不是含有金属的矿物进行参数化的。在这项研究计划中，包含金属的矿物的总溶解速率将使用批处理反应器测量，而表面比溶解速率和分子尺度机理将使用原子力显微镜测量。然后，这些测量将被用来对基于过程的溶解模型进行参数化，该模型解释了矿物表面特定位置的分子尺度的附着和脱离反应。该项目的教育目标是向非传统和多样化的转学学生以及本地本科生介绍合作研究经验，并培养未来的矿物表面地球化学家。所有学生将参加暑期研究体验，参加大学间系列研讨会，并在本科生研究研讨会上展示他们的发现。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Certain toxic and radioactive metals, such as lead and radioactive strontium, can cause environmental and health concerns when they are dissolved in surface waters or groundwater. One way to remove or prevent them from entering the environment is to incorporate them into solid minerals, where they can be immobilized for long term storage. However, incorporated metals can directly affect the rate at which these minerals dissolve and thus release contaminants back into the environment. It is not well known which metals are most likely to increase or decrease the rate at which these minerals dissolve, but that information would be helpful for designing more effective remediation strategies. The proposed project will determine how incorporated metals affect mineral dissolution rates and develop a model to better predict the stability and lifetime of minerals precipitated during environmental remediation. The project will also support, train, and promote the retention of a diverse group of undergraduate students through development of a collaborative research experience and inter-college seminar series with students at Queens College and two local community colleges. The research goal of this project is to determine the molecular scale mechanisms that drive differences in dissolution of minerals with incorporated metals as compared to their pure end-member phases. While the thermodynamic solubility of mineral phases can be used to determine the likelihood of dissolution, the rate of dissolution can be equally important, since solubility does not always correlate with reaction rates. Dissolution rates can be predicted using kinetic models, but these are typically parameterized for pure mineral phases rather than for minerals with incorporated metals. In this research plan, overall dissolution rates of minerals with incorporated metals will be measured using batch reactors while surface specific dissolution rates and molecular-scale mechanisms will be measured using atomic force microscopy. These measurements will then be used to parameterize a process-based dissolution model that accounts for molecular-scale attachment and detachment reactions at specific sites on mineral surfaces. The project's educational goals are to introduce non-traditional and diverse transfer students as well as native undergraduate students to collaborative research experiences, and to train future mineral surface geochemists. All students will participate in a summer research experience, attend an inter-college seminar series, and present their findings at an undergraduate research symposium.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.