CBET-EPSRC: Characterizing the effects of supply hours and pressure of intermittent piped water supplies on water quality

流经饮用水分配系统的水可能由于供应中断或水压低而受到污染。在美国，由于老化的基础设施系统和自然灾害，这些中断目前更为常见。在美国以外，超过10亿人每天通过管道分配系统获得不到24小时的水。本项目将研究配水系统中的定期压力损失对水质的影响。这项研究将与英国谢菲尔德大学合作，更好地了解间歇运行的管道供水系统对水质的影响，从而制定减少水传播疾病传播的战略。此外，该项目将帮助培养工程专业的学生参与国际合作和全球劳动力。该研究小组将通过招募代表性不足的人口中的本科生和研究生，以及为K-12观众开发饮用水分配系统的教育模块，来扩大工程学的参与。虽然已经研究了供水系统中连续供水的瞬时压力损失的影响，但以前没有在受控条件下研究过长期供水中断对管道微生物的影响。这项拟议的研究的贡献是阐明慢性中断影响微生物生态和病原体在生物膜和供水的散装阶段的行为的基本机制。中心假设是加压供水的频繁中断会影响生物膜的结构和组成、细菌的生长以及管道内肠道病原体的持续存在和释放。这些频繁中断的综合影响对水龙头接收的水的质量产生了负面影响。为了验证这一假设，艾米丽·昆佩尔的研究小组与英国谢菲尔德大学的研究人员合作，将：1）描述连续和间歇供应管道中大量水和生物膜的微生物学; 2）确定间歇供应管道中病原生物指示物的命运和运输;以及3）模拟间歇供水中不同供水时间对水传播疾病风险的影响。这项研究将使用谢菲尔德大学的一个国际上独一无二的600米长的温度控制，真实规模的管道回路设施。该设施中的三个水力隔离回路将采用单独的供水方案运行，以建立基线质量参数，确定微生物群落的存在、组成和功能，研究生物膜结构和组成，并调查病原体指标的存活和生长。最后，从这些实验中产生的数据将被用来开发一个定量的微生物风险评估模型，以评估不同的供应时间对水传播疾病的潜在风险的影响。通过对这些供水中断如何影响管道的微生物学进行更基本的了解，这项研究可以导致制定改善水质的战略。总的来说，这项研究可以通过识别和减少长期间歇性网络和连续加压分配系统中断所带来的健康风险来加强美国的水安全。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Water flowing through drinking water distribution systems can become contaminated due to interruptions in supply or periods of low water pressure. In the US, these interruptions are currently more common due to aging infrastructure systems and natural disasters. Outside the US, more than one billion people receive water through piped distribution systems for less than 24 hours per day. This project will study the effect of regular pressure loss in water distribution systems on water quality. In collaboration with the University of Sheffield in England, this research will provide a better understanding of the effect of intermittently operated piped water systems on water quality which can lead to strategies for the reduction of the spread of waterborne diseases. Additionally, this project will help train engineering students for engagement in international collaborations and global workforces. The research team will broaden participation in engineering by recruiting undergraduate and graduate students from underrepresented populations and by developing education modules on drinking water distribution systems for K-12 audiences. While the influence of momentary loss of pressure in otherwise continuous supplies in water distribution systems has been studied, the effect of chronic water interruptions on the microbiology of pipes was not previously examined under controlled conditions. The contribution of this proposed research is to elucidate the fundamental mechanisms by which chronic interruptions influence the microbial ecology and behavior of pathogens in biofilms and in the bulk phase of the water supply. The central hypothesis is that frequent interruptions to pressurized water supply affect the structure and composition of biofilms, the growth of bacteria, and the persistence and release of enteric pathogens within the pipes. The sum effect of these frequent interruptions is negatively influencing the quality of the water received at the tap. To test this hypothesis, the research group of Emily Kumpel, in collaboration with researchers at the University of Sheffield in England, will: 1) describe the microbiology of bulk water and biofilms in continuously and intermittently supplied pipes; 2) determine the fate and transport of indicators of pathogenic organisms in intermittently supplied pipes; and 3) model the impact of varying hours of supply in intermittent supply on the risk of waterborne disease. This proposed research will use an internationally-unique 600 m long temperature-controlled, real-scale pipe loop facility at the University of Sheffield. The three hydraulically-isolated loops in this facility will be operated with separate supply regimes to establish baseline quality parameters, determine the presence, composition, and function of microbial communities, study the biofilm structure and composition, and investigate the survival and growth of pathogen indicators. Finally, data generated from these experiments will be used to develop a quantitative microbial risk assessment model to evaluate the impact of varying hours of supply on the potential risk of waterborne disease. By gaining a more fundamental understanding of how these supply interruptions affect the microbiology of pipes, this research can lead to the development of strategies for improving water quality. Overall, this research can strengthen US water security by identifying and reducing the risks to health posed by chronically intermittent networks and by interruptions to otherwise continuously pressurized distribution systems.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.