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

该项目由化学部环境化学科学（ECS）计划资助。佐治亚理工学院的 Yuanzhi Tang 教授研究了金属杂质对锰 (Mn) 氧化物的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、营养物和有机化合物的生物地球化学循环具有重大影响，在这些循环中，锰在生命系统和环境之间转移。它还研究了生物体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和环境科学、化学和生物学的高中课程材料。它促进来自代表性不足群体、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特性。这项任务每年三月在亚特兰大科学节期间进行，这是佐治亚州最大的科学博览会，向公众展示科学和技术。具体来说，研究小组举办了一场“摇滚秀”？公众、学生和科学教育者有机会通过动手演示颜色、硬度、质地和化学变化等参数来了解矿物特性。他们还开发了一套用于演示生物矿化和矿物促进的环境修复的套件，例如化学反应过程中微生物锰氧化和颜色变化的显微镜和目视观察。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发挥着重要作用。尽管如此，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，以了解自然环境中污染物和营养物质的命运。该项目系统地研究了生物氧化锰在常见金属离子存在下形成时反应活性的变化。地质和环境方面感兴趣的过程包括阳离子和阴离子的吸附以及锰（II）诱导的非生物还原转化。受控的实验室研究可以预测性地了解不同金属离子在控制氧化锰反应性方面的相对重要性。

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.