Collaborative Research: Experimental and Computational Studies of the Role of Effluent Organic Matter in the Sensitized Transformation of Organic Contaminants

合作研究：出水有机物在有机污染物敏化转化中的作用的实验和计算研究出水有机物（处理后排放到环境中的废水中所含的有机物）在微污染物光化学处理中的作用相对未被探索。该项目的总体目标是评估水生污染物的光化学，特别侧重于光化学产生的反应中间体的产生和从流出的有机物中淬灭的测量，以及使用计算化学技术预测微污染物的速率常数。本研究的创新之处在于：1)关注具有特定官能团易受间接光解影响的水生污染物；2)从出水有机物和天然有机物中光化学生产反应中间体/淬灭的对比研究；3)光化学生成反应中间体的生成/猝灭与有机物性质的关系；4)使用计算化学来预测光化学产生的反应性中间体的反应性，评估污染物中影响反应性的特定结构细节，并区分哪些化合物类别值得通过间接光解进行处理。这些目标将通过一个主要研究机构（明尼苏达大学）和一个本科机构（西雅图大学）之间的合作，结合实地抽样、实验室实验和计算研究来实现。该项目强调研究是本科生学习经历的重要组成部分，旨在让本科生研究人员做出重大而实质性的贡献。他们将继续招募女性、少数族裔和第一代大学生加入他们的研究小组，从而扩大他们在科学界的影响力。SU和UMN之间的关系将建立这两个机构之间以及科学和工程之间的联系。这项工作的一个主要推动力是，废水处理厂下游的水体中同时存在出水有机物和微污染物，并且假设出水有机物的作用对这些污染物的命运施加了实质性的控制。一系列污染物在废水有机物溶液作用下的光化学半衰期将被测量，并与通过分子探针和淬火实验确定的光化学产生的反应中间体的稳态浓度相关。通过这种方式，对控制废水处理厂排放的污染物命运的光化学过程以及废水中有机物在污染物转化中的作用的理解将得到发展。此外，出水有机物在猝灭光化学反应产生的活性中间体中的作用及其作为抗氧化剂的作用将被阐明。计算化学研究将带来新的预测工具和对潜在反应机制的见解。因此，这项工作的实验和计算结果对于模拟污染物的命运和预测以污水为主的地表水中的污染物反应性至关重要。关于废水有机物影响水体中光化学产生的反应性中间体的信息也与病原体灭活和碳/养分循环有关，使其结果引起更广泛科学界的兴趣。

1434148Arnold1434313LatchCollaborative Research: Experimental and Computational Studies of the Role of Effluent Organic Matter in the Sensitized Transformation of Organic ContaminantsThe role of effluent organic matter (organic matter contained in treated wastewater that is discharged to the environment) in the photochemical processing of microcontaminants is relatively unexplored. The overall objective of this project is to evaluate the photochemistry of aquatic pollutants, specifically focusing on the measurement of photochemically produced reactive intermediate production and quenching from effluent organic matter and the prediction of micropollutant rate constants using computational chemistry techniques. The innovative aspects of the proposed research are: 1) the focus on aquatic contaminants with specific functional groups susceptible to indirect photolysis; 2) the side-by-side comparison of photochemically produced reactive intermediate production/quenching from effluent organic matter and from natural organic matter; 3) the relation of photochemically produced reactive intermediate production/quenching by organic matter properties; and 4) the use of computational chemistry to predict reactivity with photochemically produced reactive intermediates, evaluate specific structural details in contaminants that influence reactivity, and distinguish which compound classes merit attention with regards to processing via indirect photolysis. The goals will be met through a combination of field sampling, laboratory experiments, and computational studies via collaboration between a major research institution (University of Minnesota; UMN) and an undergraduate institution (Seattle University; SU). The project emphasizes research as an important component of the undergraduate learning experience and has been designed to have a major, substantive contribution from undergraduate researchers. The PIs will continue to recruit female, minority, and first-generation college students into their research groups, thus broadening their impact on the scientific community. The relationship between SU and the UMN will establish connections between these two institutions and between science and engineering.A major impetus for this work is that effluent organic matter and micropollutants are co-located in the waters downstream from wastewater treatment plants, and it is hypothesized that the role of effluent organic matter exerts substantial control over the fate of these contaminants. Photochemical half-lives for a series of contaminants in role of effluent organic matter solutions will be measured and related to the steady-state concentrations of photochemically produced reactive intermediates determined from molecular probe and quenching experiments. In this way, an understanding of the photochemical processes controlling the fate of contaminants emanating from wastewater treatment plants and the role of role of effluent organic matter in contaminant transformations will be developed. Additionally, the role of effluent organic matter plays in quenching photochemically produced reactive intermediates and its role as an antioxidant will be elucidated. The computational chemistry studies will lead to new predictive tools and insights into potential reaction mechanisms. Thus, the experimental and computational findings of this work will be critical in modeling pollutant fate and predicting contaminant reactivity in effluent-dominated surface waters. Information regarding photochemically produced reactive intermediates in role of effluent organic matter -impacted waters is also relevant to pathogen inactivation and carbon/nutrient cycling, making the results of interest to the broader scientific community.