Probing the impact of metal impurities on the structure, reactivity, and transformation of biogenic manganese oxides

本项目由化学学部环境化学科学（ECS）项目资助。美国佐治亚理工学院的唐元志教授研究了金属杂质对锰氧化物结构和反应性的影响。锰氧化物几乎存在于所有环境中。它们对金属、营养物质和有机化合物的生物地球化学循环有重要影响，在这些循环中，锰在生命系统和环境之间转移。研究了生物在环境相关条件下产生的锰氧化物的转化途径。该项目包括开发整合地球与环境科学、化学和生物学的高中课程材料。它促进来自代表性不足的群体和具有不同文化背景和研究经验的下一代科学家。唐教授和她的学生开展社区外展活动，向公众展示矿物和矿物属性。这项任务每年三月在佐治亚州亚特兰大科学节期间进行。这是美国最大的科学博览会，向公众展示科学技术。具体来说，研究小组会在？摇滚秀吗?在这里，公众、学生和科学教育工作者有机会通过实际操作的演示来学习矿物特性，如颜色、硬度、质地和化学变化等参数。他们还开发了一个用于演示生物矿化和矿物促进环境修复的工具包，例如在化学反应过程中显微镜和目视观察微生物Mn氧化和颜色变化。锰氧化物在许多重要营养物和污染物的生物地球化学循环中起着重要作用。然而，普遍存在的金属杂质对生物锰氧化物的结构、反应性和转化途径的影响仍然未知。需要这些知识来开发准确的预测模型，以了解污染物和营养物质在自然环境中的命运。本项目系统地考察了在常见金属离子存在下形成的生物氧化锰反应性的变化。地质和环境关注的过程包括阳离子和阴离子的吸附，以及Mn（II）诱导的非生物还原转化。受控的实验室研究导致预测洞察不同金属离子在控制锰氧化物反应性中的相对重要性。

This project is funded by the Environmental Chemical Sciences (ECS) Program of the Chemistry Division. Professor Yuanzhi Tang of the Georgia Institute of Technology investigates the impact of metal impurities on the structure and reactivity of manganese (Mn) oxides. Manganese oxides exist in nearly all environmental settings. They have significant influence on the biogeochemical cycling of metals, nutrients, and organic compounds in these cycles manganese is transferred between living systems and the environment. It also studies the transformation pathways of Mn oxides produced by living organisms under environmentally-relevant conditions. The project includes developing high school curriculum materials that integrate earth and environmental sciences, chemistry, and biology. It promotes the next generation of scientists from underrepresented groups and with different cultural backgrounds and research experiences. Professor Tang and her students develop community outreach activities to showcase mineral and mineral properties to the general public. This task is conducted annually in March during the Atlanta Science Festival, Georgia?s biggest science fair that showcases science and technologyto the general public. Specifically, the research group puts on a ?rock show? where the general public, students, and science educators have the opportunities to learn mineral properties with hands-on demonstrations of parameters such as color, hardness, texture, and chemical alteration. They also develop a kit for the demonstration of biomineralization and mineral-facilitated environmental remediation such as microscope and visual observation of microbial Mn oxidation and color changes during chemical reactions.Manganese oxides play an important role in the biogeochemical cycling of many important nutrients and contaminants. Still, much remains unknown about the influence of ubiquitous metal impurities on the structure, reactivity, and transformation pathways of biogenic Mn oxides. This knowledge is needed to develop accurate predictive models for understanding the fate of contaminants and nutrients in the natural environment. This project systematically examines the changes in biogenic Mn oxide reactivities when they are formed in the presence of common metal ions. The processes of geological and environmental interest include sorption of cations and anions, and abiotic reductive transformation induced by Mn(II). Controlled laboratory studies lead to predictive insight into the relative importance of different metal ions in controlling Mn oxide reactivity.