The Reactivity of Green Rust Towards Redox-Stable Trace Metals in Reducing Environments

该奖项来自化学学部环境化学科学项目，支持Evert Elzinga教授和他的学生研究绿锈（GR）。GR是一种氢氧化铁矿物，在某些自然和工程环境中形成，如河岸、含水层、饮用水管道和用于地下水修复的屏障等土壤。这些矿物具有很强的活性，可以通过还原/氧化（氧化还原）反应降解有机和无机污染物。人们对其中的反应知之甚少。本项目的目的是研究GR与一系列与环境有关的微量金属的化学反应性。这项工作旨在提高对还原环境中金属污染物流动性的认识，并为绿锈矿物的表面化学提供基本的见解。该项目为研究生提供科学训练。来自罗格斯-纽瓦克大学路易斯·斯托克斯少数民族参与联盟（LSAMP）项目的未被充分代表的少数民族本科生参与了这项研究。不同大小和价的微量金属（Mn（II）、Ni（II）、Zn（II）、Cd（II）、Pb（II）和Cr(III)）在一系列环境相关的地球化学条件下与GR在预平衡的缺氧悬浮液中反应。随着时间的推移监测金属的吸收，并使用基于同步加速器的x射线吸收光谱确定其作用机制。该团队使用Fe-55放射性示踪剂研究了水相和GR固体之间的Fe原子循环，并使用x射线衍射和透射电子显微镜分析监测了GR的结构和形态。这项研究为研究生和本科生，包括代表性不足的群体的成员提供了教育机会和研究机会。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

This award from the Environmental Chemical Sciences Program in the Division of Chemistry supports Professor Evert Elzinga and his students to study green rust (GR). GR is an iron-hydroxide mineral that forms in certain natural and engineered environments such soils along river banks, aquifers, drinking water lines, and barriers used for groundwater remediation. These minerals are very reactive and are known to degrade both organic and inorganic pollutants through reduction/oxidation (redox) reactions. Little is known about the reactions involved. The goal of this project is to study the chemical reactivity of GR with a series of environmentally relevant trace metals. The work aims to improve knowledge of the mobility of metal pollutants in reducing environments and provide basic insights into the surface chemistry of green rust minerals. The project provides scientific training for graduate students. Underrepresented minority undergraduate students from the Louis Stokes Alliances for Minority Participation (LSAMP) program at Rutgers-Newark are involved in the research.Trace metals of different sizes and valences (Mn(II), Ni(II), Zn(II), Cd(II), Pb(II) and Cr(III)) are reacted with GR in pre-equilibrated anoxic suspensions over a range of environmentally relevant geochemical conditions. Metal sorption is being monitored over time, and operative mechanisms are determined using synchrotron-based X-ray absorption spectroscopy. The team studies Fe atom cycling between the aqueous phase and the GR solid with Fe-55 radiotracers, and monitors the structure and morphology of GR using X-ray diffraction and transmission electron microscopy analyses. The research provides educational opportunities and exposure to research to graduate and undergraduate students, including members of underrepresented groups.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.