Photochemical Fate of Dissolved Amino Acids in Natural Aquatic Environment

该奖项由化学学部环境化学科学项目颁发，支持该项目的教授。来自密歇根理工大学的Daisuke Minakata和Paul Doskey。他们研究天然淡水中游离氨基酸与光的反应。了解和预测这些过程是很重要的，因为含氮的游离氨基酸及其降解产物参与了全球氮循环。它们还影响天然水生环境中的生物活动。废水排出物中氨基酸是主要成分之一。本研究的结果解决了含氮污染物对接收处理过的城市废水的水生系统的影响。该项目包括通过暑期青年实习计划向底特律地区的K-12高中学生开展外展活动。该计划促进环境科学领域代表性不足的群体的参与和保留。正在根据这项研究的结果举办网络研讨会，以提高公众对淡水系统的水安全和保障以及保护生态系统不受污染的重要性的认识。该奖项支持计算和实验研究和教育，以预测游离氨基酸转化的光解和基本反应途径。这种转化是由直接光解和光化学反应产生的反应中间体的间接氧化引起的。研究人员使用计算化学工具来确定具有代表性的游离氨基酸转化的基本反应途径。然后，研究小组预测每个确定的基本反应途径的动力学信息。最后，建立了一个基于基本反应的动力学模型来预测在环境相关条件下游离氨基酸及其转化产物的浓度随时间变化的分布。预测的浓度分布与实验室规模的实验观测结果进行了比较，以验证动力学模型。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 Profs. Daisuke Minakata and Paul Doskey from Michigan Technological University. They study the reactions of free amino acids in natural freshwater with light. Understanding and predicting these processes is important because nitrogen-containing free amino acids and their degradation products are involved in global nitrogen-cycling. They also affect biological activity in natural aquatic environments. The effluent of wastewater contains amino acids as one of the major components. The findings from this study address the impact of nitrogen-containing contaminants to aquatic systems that receive treated municipal wastewater. The project includes outreach activities to K-12 high school students in the Detroit region through a summer youth intern program. This program promotes the participation and retention of underrepresented groups in the environmental science field. A webinar is being developed based on the findings of this study to raise public awareness of water safety and security in freshwater systems and the importance of protecting ecosystems from contaminants. This award supports computational and experimental research and education to predict the photolytic and elementary reaction pathways of free amino acid transformation. This transformation is induced by direct photolysis and indirect oxidation by photochemically produced reactive intermediates. The researchers use computational chemistry tools to identify the fundamental elementary reaction pathways of representative free amino acids transformation. The research team then predicts the kinetics information of each identified elementary reaction pathway. Finally, a kinetic model based on elementary reactions is developed to predict the time-dependent concentration profiles of free amino acids and their transformation products in environmentally relevant conditions. The predicted concentration profiles are compared to laboratory-scale experimental observations to validate the kinetic model.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.