Disinfection Resiliency and Microbial Risk in Drinking Water Distribution Systems During Extreme Heat Disasters

极端热灾期间饮用水分配系统的消毒弹性和微生物风险

• 批准号: 2242705
• 负责人: Kirin Furst
• 金额: $ 38.54万
• 依托单位: George Mason University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-11-15 至 2025-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2242705&HistoricalAwards=false
• 关键词: Disinfection; Resiliency; Microbial; Risk; Drinking

Extreme heat disasters are increasingly common across the US, with many cities experiencing multiple consecutive days above 95°F (35°C). Extreme heat directly impacts drinking water quality by increasing the water temperature within distribution systems. High temperatures can compromise the efficacy of disinfection against microbial pathogens by increasing the decay rates of disinfectant residuals in distribution systems. Warmer temperatures can simultaneously stimulate growth of opportunistic pathogens which can cause acute illness or death. Thus, the failure of disinfection in drinking water distribution systems during an extreme heat disaster could cause a community outbreak of illness that would further stress hospital resources and lead to loss of life. This Disaster Resilience Research Grants (DRRG) project will contribute to understanding the risk of extreme heat to the microbial and chemical safety of drinking water and help identify engineering solutions to build water system resilience. The findings will inform water utility disaster response and preparedness plans, ensuring the ability to provide clean water during extreme heat events. Findings will be communicated to utilities through stakeholder organizations and targeted outreach to at-risk water systems, such as those serving low-income communities along the Southwestern border that experience frequent extreme heat events. This project provides an enriching experience for graduate and undergraduate trainees at two diverse public universities and will introduce underrepresented students to exciting, impactful STEM research. The transfer of knowledge between two early career investigators will prime both labs for future innovations in water quality and resilience engineering. This project will evaluate the effect of extreme heat on efficacy of disinfection in drinking water distribution systems and evaluate a novel engineering solution to increase resiliency. Most disinfection studies are limited to 30 °C, which is not informative for high water temperatures possible during extreme heat events. Simulated distribution system experiments will be conducted under extreme heat conditions (35-60 °C) to elucidate disinfectant decay kinetics of conventional chlorine and chlorocyanurates, an emerging chlorine alternative recently approved for drinking water treatment. We anticipate that chlorocyanurate disinfection will be more resilient to high temperatures and maintain higher microbial protection than conventional chlorine. The growth kinetics of legionellae and the required disinfection exposure to achieve inactivation will be determined with simulated distribution system experiments under extreme heat conditions, comparing conventional chlorine and chlorocyanurate disinfection. These experiments will produce chemical kinetics and microbial inactivation models that will be combined with a heat transfer model fit to real distribution system temperatures from a Southwestern US city to quantify the anticipated disinfection failure rate under a range of extreme heat scenarios. In each scenario, the failure rate with chlorine will be compared to the proposed chlorocyanurate intervention. This project takes an interdisciplinary approach to determine the extent to which extreme heat events compromise disinfection and microbial safety in drinking water distribution systems. The integration of aquatic chemistry, microbiology, and thermodynamics will produce holistic understanding of disinfection efficacy under extreme heat conditions. Bacterial inactivation results will provide critical insights into the persistence of this dangerous pathogen in drinking water distribution systems under extreme heat. This work will advance scientific understanding of how to mitigate health risk in US drinking water systems increasingly subjected to extreme heat.This award is co-funded by the NSF CMMI Disaster Resilience Research Grants and CBET Environmental Engineering Programs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

极端高温灾难在美国越来越普遍，许多城市连续多天温度超过 95°F (35°C)，导致供水系统内的水温升高，从而直接影响饮用水质量。通过增加供水系统中消毒剂残留物的腐烂率来对微生物病原体进行消毒。较高的温度会同时刺激机会性病原体的生长，从而导致急性疾病或死亡。因此，在极端高温灾害期间，饮用水分配系统的消毒失败可能会导致这种情况。原因社区疾病爆发将进一步加剧医院资源压力并导致生命损失。该抗灾研究补助金 (DRRG) 项目将有助于了解极端高温对饮用水微生物和化学安全的风险，并帮助确定工程解决方案。建立供水系统的复原力。研究结果将为供水公司的灾难响应和准备计划提供信息，确保在极端高温事件期间提供清洁水的能力。研究结果将通过利益相关者组织和针对风险供水系统的外展活动传达给公用事业公司。作为那些为低收入社区服务的人该项目为两所不同公立大学的研究生和本科生提供了丰富的经验，并将向代表性不足的学生介绍令人兴奋、有影响力的 STEM 研究，这将促进两位早期职业研究人员之间的知识转移。该项目将评估极端高温对饮用水分配系统消毒效果的影响，并评估一种提高弹性的新颖工程解决方案，大多数消毒研究仅限于 30°C。哪个对于极端高温事件期间可能出现的高水温而言，模拟分配系统实验将在极端高温条件下（35-60°C）进行，以阐明传统氯和氯氰尿酸盐（最近批准用于饮用的新兴氯替代品）的消毒剂腐烂动力学。我们预计氯氰尿酸盐消毒剂比传统氯消毒剂更能耐受高温，并能保持更高的微生物保护作用。军团菌的生长动力学和所需的消毒暴露。实现灭活的方法将通过极端高温条件下的模拟分配系统实验来确定，比较传统的氯和氯氰尿酸盐消毒，这些实验将产生化学动力学和微生物灭活模型，这些模型将与适合真实分配系统温度的传热模型相结合。美国西南部城市量化了一系列极端高温情况下的预期消毒失败率。在每种情况下，氯的失败率将与拟议的氯氰尿酸盐干预措施进行比较。确定极端高温事件对饮用水分配系统的消毒和微生物安全的影响程度的方法将水生化学、微生物学和热力学相结合，将产生对极端高温条件下消毒效果的全面了解。这项工作将深入研究这种危险病原体在极端高温下饮用水分配系统中的持续存在，这将促进人们对如何减轻日益遭受极端高温的美国饮用水系统的健康风险的科学认识。该奖项由 NSF CMMI 共同资助。抗灾研究补助金和 CBET 环境工程计划。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。