Collaborative Research: Linking Dissolved Organic Matter Composition to Photochemical Reactivity

合作研究：将溶解的有机物成分与光化学反应性联系起来

• 批准号: 1802458
• 负责人: Kristine Wammer
• 金额: $ 9.52万
• 依托单位: University of St. Thomas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1802458&HistoricalAwards=false
• 关键词: Collaborative; Research; Linking; Dissolved; Organic

Chemicals, such as pesticides and pharmaceuticals, are commonly found in lakes, rivers, and other surface waters. It is important to know how quickly these chemicals break down in the environment due to natural processes in order to assess their potential risks to humans and ecosystems. This research project studies the role of sunlight in the degradation of pesticides and pharmaceuticals in a process known as photodegradation. This process is driven by the photochemical reactions of dissolved organic matter (DOM), which is a complex mixture of organic chemicals derived from plants and microorganisms that is found in all natural waters. The chemical composition of DOM is highly variable in different waters, and these compositions influence how quickly pesticides and pharmaceuticals break down when exposed to sunlight. Therefore, this project will develop a framework to predict the relative photoreactivity of a wide variety of DOM samples collected from rivers, bogs, lakes, and wastewater treatment plants located in forested, agricultural, and urban watersheds. By developing predictive models based on DOM composition measurements, this research will lay the groundwork for predicting the degradation rates of chemicals in aquatic systems. If successful, this knowledge can be used to identify and isolate chemical contaminants in the Nation's natural waters, thereby protecting the environment and public health. This project aims to link the composition of dissolved organic matter (DOM) to its photochemical reactivity. While state-of-the-art techniques such as high-resolution mass spectrometry provide more information about DOM composition than ever before, it is still not possible to predict the reactivity of DOM based solely on its composition due to the heterogeneity of this complex mixture. This research collaboration between the University of Wisconsin-Madison and the University of St. Thomas will test the hypothesis that a combination of parameters derived from a variety of analytical techniques can be used to predict relative photochemical reactivity within a diverse set of DOM samples. The principal investigators hypothesize that a subset of the data produced by the different techniques contributes strongly to variance in DOM reactivity because each technique samples different populations of DOM. In order to test this hypothesis, river and lake samples will be collected from five watersheds (St. Louis River, Yahara, Northern Highlands, Minnesota River, and Mississippi River), as well as samples before and after disinfection at five wastewater treatment plants. Collectively, these sites represent the range of natural freshwaters that are impacted by polar contaminants, such as pesticides and pharmaceuticals. These samples will be characterized by UV-visible spectroscopy, antioxidant measurements, and both Fourier transform-ion cyclotron resonance (FT-ICR) and Orbitrap mass spectrometry. Photoreactivity will be assessed using probe studies to quantify the quantum yields and steady-state concentrations of reactive species and by experiments with five target pesticides and pharmaceuticals. Multivariate statistics, including multiple linear regressions, hierarchical cluster analysis, and principal component analysis, will be used to develop a novel framework to predict the relative photochemical reactivity of natural and effluent organic matter based on composition. Finally, this unique data set will be used to test whether Orbitrap mass spectrometry is able to provide sufficient information to replace the use of FT-ICR mass spectrometry in determining the molecular composition of DOM for reactivity studies.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.

化学物质，例如农药和药物，通常在湖泊，河流和其他地表水中发现。重要的是要知道，由于自然过程，这些化学物质在环境中分解的速度如何，以评估其对人类和生态系统的潜在风险。该研究项目研究了阳光在称为光降解的过程中阳光在农药和药物降解中的作用。该过程是由溶解有机物（DOM）的光化学反应驱动的，这是在所有天然水域中发现的植物和微生物的有机化学物质的复杂混合物。 DOM的化学成分在不同的水域中高度可变，并且这些成分会影响农药和药物暴露于阳光时分解的速度。因此，该项目将开发一个框架，以预测从河流，沼泽，湖泊和废水处理厂收集的各种DOM样品的相对光电反应性，并位于森林，农业和城市流域中。通过开发基于DOM组成测量的预测模型，这项研究将为预测水生系统中化学物质的降解速率奠定基础。如果成功，这些知识可用于识别和隔离美国自然水域中的化学污染物，从而保护环境和公共卫生。该项目旨在将溶解有机物（DOM）的组成与其光化学反应性联系起来。尽管高分辨率质谱等最新技术提供了比以往更多有关DOM组成的信息，但由于这种复杂混合物的异质性，仍然不可能仅基于其成分来预测DOM的反应性。威斯康星大学麦迪逊分校和圣托马斯大学之间的这项研究合作将检验以下假设：可以使用各种分析技术衍生的参数组合来预测各种DOM样品集中的相对光化学反应。主要研究人员假设由不同技术产生的数据子集有很大的贡献导致DOM反应性方差，因为每种技术都样本了不同的DOM种群。为了检验这一假设，将从五个流域（圣路易斯河，Yahara，Yahara，Northern Highlands，Minnesota River和Mississippi River）中收集河流和湖泊样品，以及在五个废水处理工厂进行消毒之前和之后的样品。总的来说，这些地点代表了受极地污染物（例如农药和药物）影响的天然淡水范围。这些样品将以紫外可见光谱，抗氧化剂测量以及傅立叶转化离子回旋共振（FT-ICR）和Orbitrap质谱法的特征。光电反应性将使用探针研究评估，以量化反应性物种的量子产率和稳态浓度，并通过使用五种靶农药和药物的实验进行测量。多元统计数据，包括多个线性回归，分层群集分析和主成分分析，将用于开发一个新型框架，以预测基于组成的自然和废水有机物的相对光化学反应性。 Finally, this unique data set will be used to test whether Orbitrap mass spectrometry is able to provide sufficient information to replace the use of FT-ICR mass spectrometry in determining the molecular composition of DOM for reactivity studies.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.