Understanding the Role of Biofilm on Disinfection By-Product Formation and Fate in the Water Distribution System

1236433 Seo与我们对水处理厂中消毒副产物（DBP）形成的理解相反，在水处理厂中，水质参数和DBP的形成可以同时监测，配水系统中DBP的形成还没有得到很好的理解，这主要是由于配水系统中相互作用的复杂性。最近的研究表明，生物膜的存在不仅影响水的生物稳定性，而且通过与残留消毒剂反应影响配水系统中水的化学稳定性。此外，生物膜可以为本体流体中存在的各种有机材料提供动态储存库，并随后将它们用作主要营养源。考虑到生物膜的持久性和当前对供水设施中生物膜爆发的操作响应，包括增加残留消毒剂的浓度以抑制生物膜，生物膜可能是配水系统中DBP形成的主要贡献者之一。除了增加生物膜中DBP形成的可能性外，最近的研究还报道，配水系统中DBP的生物降解与异养细菌的存在密切相关。虽然许多公共和工业部门正在努力克服生物膜形成的持久性及其在具有消毒实践的配水系统中的传播，但在生物膜消毒期间可能会产生不需要的DBP。为了解决目前的知识差距，本研究的目的是调查生物膜的DBP的形成和降解在供水系统中的作用。拟议的测试将应用各种生化分析工具，DBP分析，微电极技术和分子工具，以监测生物膜的生长，消毒剂运输，DPB的形成和降解，从而提供了一个机械的理解反应，消毒剂的衰减，和生物膜的有机基质的DBPs的生产。总体而言，研究成果将解决我们目前关于配水系统中形成的生物膜形成DBP的知识缺口，并提高我们预测和识别有害DBP形成的能力，这将有助于保护公众健康免受有害生物膜和DBP形成的影响。在拟议的研究期间完成的任务将产生强大的信息，以了解DBP形成的机制以及DBPs在分配系统中的命运。这可以帮助许多水设施评估和优化生物膜控制的消毒剂实践，同时最大限度地减少配水系统中DBP的形成。此外，拟议的项目将为博士生提供培训和教育，并为本科生和高中生提供暑期研究机会。研究结果也将纳入PI的本科课程。此外，研究结果将被介绍到PI的外联和服务活动，为代表性不足的K-12学生和工程师无国界项目在洪都拉斯。

1236433SeoIn contrast to our understanding of disinfection by-product (DBP) formation in water treatment plants, where water quality parameters and the formation of DBPs can be monitored simultaneously, the formation of DBPs in water distribution systems is not well understood due largely to the complexity of interactions occurring in water distribution systems. Recent studies have indicated that the presence of biofilm impacts not only the biological stability of water but also the chemical stability of water in distribution systems via reaction with residual disinfectant. Moreover, biofilm can provide a dynamic repository for various organic materials present in the bulk fluid and subsequently utilize them as a primary nutrient source. Considering the persistence of biofilm and current operational responses to biofilm outbreak in water utilities, which include increasing the concentration of residual disinfectants to inactivate biofilm, biofilm may be one of the primary contributors to DBP formation in distribution systems. Beyond increased DBP formation potential from biofilm, recent studies also reported that biological degradation of DBPs in water distribution system was strongly related to the presence of heterotrophic bacteria. While many public and industrial sectors are working to overcome the persistence of biofilm formation and its dissemination in water distribution systems with disinfection practices, unwanted DBPs may be generated during biofilm disinfection. To address the current knowledge gap, this study aims to investigate the role of biofilm on DBP formation and degradation in water distribution systems. The proposed tests will apply various biochemical analysis tools, DBP analysis, microelectrode techniques, and molecular tools to monitor biofilm growth, disinfectant transport, DPB formation, and degradation, thus providing a mechanistic understanding of reactions, decay of disinfectants, and the production of DBPs by the organic matrix of biofilm. Overall, research outcomes will address our current knowledge gap regarding DBP formation by biofilms that form in water distribution systems and improve our ability to predict and identify harmful DBP formation, which will contribute to protecting public health from both harmful biofilm and DBP formation. Tasks completed during the proposed study will generate robust information toward understanding the mechanisms of DBP formation as well as the fate of DBPs in distribution systems. This may assist many water utilities to assess and optimize disinfectant practices for biofilm control while minimizing DBP formation in water distribution systems. In addition, the proposed project will provide training and education for Ph.D students as well as summer research opportunities for undergraduate and high school students. Research findings will also be incorporated into the PI's undergraduate courses. Furthermore, research findings will be introduced in the PI's outreach and service activities for underrepresented K-12 students and for Engineers Without Borders Projects in Honduras.