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

1434148 Arnold1434313 LatchCollaborative Research：流出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流出有机物(排放到环境中的处理过的废水中的有机物)在微污染物的光化学处理中的作用相对较少被探索。该项目的总体目标是评估水生污染物的光化学，特别是利用计算化学技术测量光化学产生的活性中间产物和从流出的有机物中猝灭以及预测微污染物速率常数。拟议研究的创新方面是：1)重点关注具有容易间接光解的特定官能团的水生污染物；2)从流出的有机物和天然有机物并列比较光化学产生的活性中间体/猝灭；3)光化学产生的活性中间体/猝灭与有机物性质的关系；以及4)使用计算化学来预测与光化学产生的活性中间体的反应活性，评估影响反应活性的污染物的特定结构细节，并区分间接光解处理中值得注意的化合物类别。这些目标将通过现场采样、实验室实验和计算研究相结合的方式实现，通过主要研究机构(明尼苏达大学；UMN)和本科生机构(西雅图大学；苏黎世)之间的合作实现。该项目强调研究作为本科生学习经验的重要组成部分，并已被设计为有来自本科生研究人员的重大、实质性的贡献。PIS将继续招募女性、少数民族和第一代大学生加入他们的研究小组，从而扩大他们对科学界的影响。SU和UMN之间的关系将在这两个机构之间以及科学和工程之间建立联系。这项工作的一个主要推动力是，出水有机物和微污染物共存于污水处理厂下游水域，并假设出水有机物的作用对这些污染物的去向起到很大的控制作用。将测量一系列污染物在流出有机物溶液中的光化学半衰期，并与分子探针和猝灭实验确定的光化学产生的活性中间体的稳态浓度相关。通过这种方式，将加深对控制废水处理厂排放污染物去向的光化学过程的理解，以及废水有机物在污染物转化中的作用。此外，还将阐明流出的有机物在猝灭光化学产生的活性中间体中所起的作用及其作为抗氧化剂的作用。计算化学研究将带来新的预测工具和对潜在反应机理的洞察。因此，这项工作的实验和计算结果对于模拟污染物的去向和预测以污水为主的地表水中污染物的反应性将是至关重要的。关于光化学产生的活性中间体在受废水有机物影响的水中的作用的信息也与病原体灭活和碳/养分循环有关，这使更广泛的科学界对结果感兴趣。

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.