LEAPS-MPS: Exploration of heterogenous reactions of mercury in the Arctic environment

该奖项由环境化学科学计划和化学部的扩大参与计划支持。宾夕法尼亚州立大学哈里斯堡分校的Asaduzzaman教授和他的学生通过进行量子化学计算来研究氧化汞物质与雪和冰的反应。 汞是一种有毒元素，对哺乳动物和人体造成严重的健康问题。它可以通过大气进行长距离传输，并在水生食物生态系统中放大。在北极大气中的卤素、臭氧和硝基化合物的存在下氧化后，它沉积在冰雪表面。氧化汞化合物然后通过冰层扩散，到达水生环境，在那里它们转化为甲基汞，然后很容易被浮游生物吸收，成为食物网中的生物磁体。该项目的重点是确定氧化汞化合物与雪和冰相互作用的基本步骤，这些步骤控制着汞到达水生环境的过程。这项研究有可能了解汞在北极表面的沉积，还原和扩散的机制。该项目通过教师研究经验计划为多名本科生和一名高中教师提供研究机会。研究将侧重于使用量子化学方法计算氧化汞与冰雪的原子尺度相互作用。该项目将探索氧化汞在冰雪表面的沉积，以及减少沉积汞并将其重新排放到大气中。该项目有助于了解汞与冰雪的许多反应，沉积汞向冰中的扩散，以及无机汞化合物向有机汞化合物的转化。 研究结果将有助于确定汞氧化还原过程中的限速步骤，并最终有助于开发更准确的全球大气汞模型。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

This award is supported by the Environmental Chemical Sciences Program and the Broadening Participation Program in the Division of Chemistry. Professor Asaduzzaman at the Pennsylvania State University Harrisburg and his students study the reactions of oxidized mercury species with snow and ice by performing quantum chemical calculations. Mercury is a toxic element that poses severe health issues to the mammalian and human body. It can be transported long distances via the atmosphere and magnify in aquatic food ecosystems. After oxidation in presence of halogens, ozone, and nitro compounds in the Arctic atmosphere, it is deposited on snow and ice surfaces. The oxidized mercury compounds then diffuse through the ice and reach the aquatic environment, where they convert into methylmercury, which is then readily taken up by plankton and is biomagnified in the food web. This project focuses on characterizing the elementary steps for the interactions of oxidized mercury compounds with snow and ice, which control the process for mercury reaching the aquatic environment. This research has potential to understand the mechanism for mercury deposition, reduction, and diffusion on the Arctic surface. The project provides research opportunities for multiple undergraduate students and a high school teacher through a research experience for teachers program. The research will focus on calculating the atomic scale interaction of oxidized mercury with ice and snow using the quantum chemical methodologies. The project will explore the deposition of oxidized mercury on the ice/snow surface, and the reduction and re-emission of deposited mercury into the atmosphere. This project can help understand many reactions of mercury with ice and snow, diffusion of deposited mercury into the ice, and conversion of inorganic to organic mercury compounds. The results will aid in determining the rate-limiting steps in the mercury oxidation-reduction processes, and ultimately in developing more accurate global atmospheric mercury models.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.