Collaborative Research: Role of Organic Matter Source on the Photochemical Fate of Pharmaceutical Compounds

PIS：Allison MacKay/Yu-Ping Chin/Charles Sharples建议编号：1133600/1133094/1132207评估人类药物化合物对环境的影响是一项艰巨的任务，因为医疗条件下使用的化学品种类繁多，而且各种废水管理方案有助于将其释放到水中系统。先前的研究表明，光降解反应是药物化合物在环境中的重要衰减过程。药物对光化学反应的敏感性将受到这些化合物与出水有机物(EfOM)共释放的影响。与研究充分的天然有机物(NOM)来源相比，EfOM预计具有不同的光反应性，这可能是因为与NOM相比，EfOM预期的芳香含量和颜色更低。PI假设药物化合物的光降解将随着废水在自然流道中所占比例的增加而改变，因为相对于NOM，EfOM的存在增加了。拟议研究的最终目标是确定与提高药物化合物的环境光降解率有关的关键环境系统特征。他们提出了三项主要的研究活动来评估他们的假设。(1)：对于典型的废水排放情景，将获得环境退化速度和路径的现场测量？森林覆盖的新英格兰分水岭(康涅狄格州蓬佩罗格河)、中西部农业分水岭(俄亥俄州小迈阿密河东福克)和带有联合下水道排污口的城市溪流(帕克河，康涅狄格州)。将在流出物排放的下游采集流量调整的样品，以测量具有不同季节EfOM与NOM比率的伪一级环境退化速率。通过比较白天和夜间的观察，光解损失将与其他损失区分开来。支持实验室降解研究将解决有机物(OM)类型对光化学途径的贡献。(2)：将从现场分离OM，包括直接从流出物中分离。将采用XAD-8树脂分离法和切向流超滤法，以保证与地球化学法的一致性。将对分离的菌株进行生化成分(热化学分解)以及光学和结构特性(UV-Vis、荧光、固态13C核磁共振)的表征。(3)：将获得OM分离株的单态氧、过氧化氢和激发三态OM的量子产率，并将其与OM特性相关联(任务2)。总而言之，任务2和任务3的结果将产生关键的见解，以解释不同地点和不同季节之间光降解速率常数(任务1)的差异，因为每个地点的污水贡献不同。这项研究将在之前干旱系统命运研究的基础上，首次研究新英格兰和中西部河流中药物化合物的命运。他们将建立一个关于药物化合物命运的环境系统驱动因素的重要知识体系，这将有助于做出关于监管、补救和/或绿色？用于药物化合物的设计。他们将与蓬佩劳格河流域联盟和东福克流域合作社密切合作，通过半年一次的项目进展报告，让公民参与尖端科学，让水资源管理者和社区成员参与水质采样，并组织一次跨学科圆桌会议，将环境科学家和工程师、监管者与生态学家和药理学家聚集在一起，讨论环境中药物化合物的环境管理。PIS将指导研究生和本科生研究人员完成科学发现的过程吗？实验设计、手稿准备和国家专业学会演讲。PIS将继续其从科学和工程领域代表性较低的群体聘请学生研究人员的记录。学生们将有一个独特的机会与具有工程(Pi MacKay)、地球化学(Pi Chin)、光化学(Pi Sharpless)和系统生态学(合作者Nietch)专业知识的PI指导团队合作，为他们自己的项目提供广泛的背景。

PIs: Allison MacKay / Yu-Ping Chin / Charles SharplessProposal Numbers: 1133600 / 1133094 / 1132207Evaluating the impacts of human pharmaceutical compounds in the environment is a daunting task, given the wide variety of chemicals administered for medical conditions and the various wastewater management schemes that facilitate their release to aquatic systems. Prior studies suggest photodegradation reactions to be important attenuation processes for pharmaceutical compounds in the environment. The susceptibility of pharmaceuticals to photochemical reactions will be impacted by the co-release of these compounds with effluent organic matter (EfOM). EfOM is expected to have differing photoreactivity, relative to well-studied natural organic matter (NOM) sources, presumably because of its anticipated lower aromatic content and lower color, compared to NOM. The PIs hypothesize that pharmaceutical compound photodegradation will be altered with increasing proportion of wastewater effluent in natural channel flow because of the increased presence of EfOM, relative to NOM. The ultimate goal of the proposed research is to identify key environmental system characteristics that are associated with enhanced environmental photodegradation rates of pharmaceutical compounds. They propose three major research activities to evaluate their hypothesis. (1): Field measurements of environmental degradation rates and pathways will be obtained for representative wastewater discharge scenarios ? forested New England watershed (Pomperaug River, CT), agricultural Midwestern watershed (East Fork of the Little Miami River, OH), and an urban stream with combined sewer outfalls (Park River, CT). Flow-adjusted samples will be obtained downstream of the effluent discharge to measure pseudo-first order environmental degradation rates with differing seasonal EfOM-to-NOM ratios. Photolysis losses will be differentiated from other losses by comparing daytime and nighttime observations. Supporting lab degradation studies will resolve contributions of organic matter (OM) type to photochemical pathways. (2): OM will be isolated from the field sites, including from effluent streams directly. Isolation methods of XAD-8 resin and tangential flow ultrafiltration will be used for consistency with geochemistry methods. Isolates will be characterized for their biochemical constituents (thermochemolysis), and for optical and structural properties (UV-Vis, fluorescence, solid-state 13C NMR). (3): Quantum yields of singlet oxygen, hydrogen peroxide and excited triplet-state OM will be obtained for OM isolates and correlated to OM characteristics (Task 2). Together, the results of Tasks 2 and 3 will yield critical insights for interpreting differences in photodegradation rate constants (Task 1) among the sites and within seasons, as effluent contributions change at each site. This study will be the first to examine the fate of pharmaceutical compounds in New England and Midwestern rivers, expanding on prior fate studies from arid systems. They will establish an important body of knowledge about environmental system drivers of pharmaceutical compound fates that will contribute to robust science-based decisions about regulation, remediation, and/or ?green? design for pharmaceutical compounds. They will work closely with the Pomperaug River Watershed Coalition and the East Fork Watershed Cooperative to engage citizens in cutting-edge science through semi-annual project progress presentations, to involve water managers and community members in water quality sampling, and to organize a cross-disciplinary Roundtable to bring together environmental scientists and engineers, regulators, with ecologists and pharmacologists to discuss environmental management of pharmaceutical compounds in the environment. The PIs will mentor graduate and undergraduate researchers through the process of scientific discovery ? experimental design, manuscript preparation and national professional society presentations. The PIs will continue their record of engaging student researchers from groups underrepresented in the sciences and engineering. Students will have a unique opportunity to work with a guiding PI team with expertise in engineering (PI MacKay), geochemistry (PI Chin), photochemistry (PI Sharpless) and systems ecology (Collaborator Nietch), providing broad context for their own projects.