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

主要研究者：Natalie Mladenov提案ID：1705901美国和许多发达国家的废水基础设施基本上是集中式的，许多系统正在达到其设计寿命的终点。作为替换数千英里的下水道管道的替代方案，分散式废水处理系统（DEWATS）与膜过滤和其他先进处理技术相结合，可以满足社区一级的供水需求。水再利用和再循环系统中的一个重要挑战是多种类型的污染物的持久性，包括新出现的关注污染物（CEC），例如可能数以千计并且经常在废水流出物和接收沃茨中检测到的药物活性化合物。在处理过程中产生的污染物及其潜在的副产品对人类健康构成了不明确的风险，这些化学品在DEWATS中被去除或转化的机制是该项目寻求解决的关键问题。这项研究将采用系统的非针对性分析方法，全面识别实验室规模的膜处理系统中已知和意外的污染物和副产物。该项目还将通过开展水再利用演示和竞赛活动，向圣地亚哥州立大学全女生“We Are STEM Enrichment Program”中学女生传达水资源短缺和再利用的主题，促进教育和多样性。利用好氧和厌氧膜生物反应器技术（分别为MBR和AnMBR）的DEWATS，特别是如果与额外的抛光步骤相结合，有可能提供与传统集中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上级处理，包括在处理过的沃茨和环境中检测到的CEC。对于通过DEWATS进行的厌氧处理，目前对污染物命运的理解是围绕传统的大型好氧处理系统开发的，这是不完整的，需要在这方面进行研究，以促进厌氧系统的使用。在MBR和AnMBR处理过程中形成了多种母体化合物以及未知毒性的代谢物。本研究的目的是1）评价好氧和厌氧膜生物反应器系统中污染物的去除和转化机理; 2）加强MBR和AnMBR系统中母体化合物以及副产物的鉴定。 本研究将采用基于气相色谱-飞行时间质谱联用（GC×GC/TOF-MS）的非靶向分析，以全面识别已知和未知化学品及其生物转化和光转化产物。该研究还将调查光解作用如何有助于化学物质的去除和转化，光解作用在往往遵循厌氧处理的池塘或湿地处理系统中至关重要。这项工作的影响将是深远的水回用领域，因为这种更详尽的评估化学品和它们在小规模膜处理系统的转化将通知在美国和国外日益分散的运动。

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.