WERF: Enhanced evaluation of the removal of contaminants of emerging concern in decentralized water reuse systems by non-targeted analysis

PI: Natalie MladenovProposal ID: 1705901美国和许多发达国家的污水基础设施在很大程度上是集中式的，许多系统正在达到其设计寿命的终点。分散式污水处理系统（DEWATS）与膜过滤和其他先进的处理技术相结合，可以替代数千英里的污水管道，满足社区一级的供水需求。水再利用和再循环系统的一个重要挑战是多种污染物的持续存在，包括新出现的污染物（CECs），例如可能有数以万计的药物活性化合物，并且经常在废水排放和接收水中被检测到。在处理过程中产生的污染物及其潜在副产品对人类健康构成不明确的风险，而在废水处理系统中去除或转化这些化学品的机制是本项目寻求解决的关键问题。本研究将采用系统的非目标分析方法，全面识别实验室规模膜处理系统中已知和意外的污染物和副产品。该项目还将通过开发水再利用演示和竞赛活动来促进教育和多样性，向圣地亚哥州立大学全女生We Are STEM浓缩项目的中学女生传达有关水资源短缺和再利用的主题。利用好氧和厌氧膜生物反应器技术（分别为MBR和AnMBR）的DEWATS，特别是如果加上额外的抛光步骤，有可能提供与传统集中式处理厂相当或更好的处理水平，并将在增加非饮用水和饮用水供应方面发挥作用。在DEWATS中实施膜反应器的关键是确保这些系统符合当前的水质标准，并为多种污染物提供卓越的处理，包括在处理过的水和环境中检测到的CECs。对于通过DEWATS进行厌氧处理，目前对污染物命运的了解是不完整的，这是围绕传统的大型好氧处理系统发展起来的，需要在这方面进行研究以推进厌氧系统的使用。在MBR和AnMBR处理过程中形成了多种母体化合物以及毒性未知的代谢物。本研究的目的是1)评估好氧和厌氧膜生物反应器系统中污染物的去除和转化机制；2)加强MBR和AnMBR系统中母体化合物和副产物的识别。本研究将采用基于气相色谱耦合飞行时间质谱（GC×GC/TOF-MS）的非靶向分析，以全面鉴定已知和未知的化学物质及其生物转化和光转化产物。该研究还将调查在厌氧处理之后的池塘或湿地处理系统中至关重要的光解作用如何有助于化学物质的去除和转化。这项工作的影响将对水再利用领域产生深远的影响，因为对化学品及其在小规模膜处理系统中的转化进行的更详尽的评估将为美国和国外日益增长的分散运动提供信息。

PI: Natalie MladenovProposal ID: 1705901 The wastewater infrastructure in the United States and many developed countries is largely centralized and many systems are reaching the end of their design life. As an alternative to replacing thousands of miles of failing sewer pipe, decentralized wastewater treatment systems (DEWATS) coupled with membrane filtration and other advanced treatment technologies can meet water supply needs at the community-level. One important challenge in water reuse and recycling systems is the persistence of multiple types of contaminants, including contaminants of emerging concern (CECs) such as pharmaceutically active compounds that potentially number in the thousands and have frequently been detected in wastewater effluent and receiving waters. The contaminants and their potential byproducts generated during the treatment process pose an unclear risk to human health, and the mechanisms by which these chemicals are removed or transformed in DEWATS are key issues this project seeks to address. This research will employ a systematic non-targeted analytical approach to comprehensively identify both known and unexpected contaminants and byproducts in lab-scale membrane treatment systems. This project will also advance education and diversity through development of a Water Reuse Demo and Competition activity to convey themes dealing with water scarcity and reuse to middle school girls in the all-female We Are STEM Enrichment Program at San Diego State University. DEWATS that utilize aerobic and anaerobic membrane bioreactor technology (MBR and AnMBR, respectively), especially if coupled to additional polishing steps, have the potential to provide treatment at levels comparable to or better than conventional centralized treatment plants and will have a role in augmenting non-potable and potable water supplies. A key to the implementation of membrane reactors in DEWATS is ensuring that these systems meet current water quality standards and offer superior treatment for multiple classes of contaminants, including CECs that are detected in treated waters and the environment. For anaerobic treatment via DEWATS, the current understanding of the fate of contaminants, which has been developed around conventional large-scale aerobic treatment systems, is incomplete, and research on this front is needed to advance the use of anaerobic systems. There is a diversity of parent compounds as well as metabolites of unknown toxicity that are formed during MBR and AnMBR treatment. The goals of this research are to 1) evaluate the removal and transformation mechanisms for contaminants in aerobic and anaerobic membrane bioreactor systems and 2) enhance the identification of parent compounds as well as byproducts in MBR and AnMBR systems. This research will employ a non-targeted analysis based on gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS) in order to comprehensively identify both known and unknown chemicals and their bio-transformation and photo-transformation products. The research will also investigate how photolysis, which is critical in pond or wetland treatment systems that tend to follow anaerobic treatment, contributes to chemical removal and transformation. The impact of this work will be far reaching for the water reuse field because this more exhaustive evaluation of chemicals and their transformation in small-scale membrane treatment systems will inform the growing decentralized movement in the US and abroad.