RAPID: Chemical Air Emissions from Cured-in-Place-Pipe (CIPP) Pipe Repair Activity

1624183惠尔顿北美的城市和公用事业公司正在使用现场固化管道“非开挖”更新技术修复数百万英里的破损下水道管道。与此同时，全国各地的州交通机构也依靠CIPP修复数百万英里的雨水涵洞。现场固化管道修复方法包括将树脂浸渍织物安装到恶化的管道或涵洞中，然后用热（热水或蒸汽）或紫外线进行原位固化。现场固化管是由聚合物树脂交联而成。有证据表明，蒸汽和热水固化的现场固化下水管道维修活动产生的化学排放物可能对人类健康和环境构成风险。该项目的目标是了解蒸汽固化管道安装的化学气体排放，这是最受欢迎的现场固化管道技术之一。2015年12月对美国某城市三个蒸汽固化管道安装地点进行的化学排放研究表明，苯乙烯以大于1，000 ppm的浓度排放到空气中，超过了所有监管工作场所暴露标准。报告的浓度水平远远超过了国际毒性估计值，即儿童等最易受影响人群的20 ppm风险值。苯乙烯是蒸汽固化的现场固化管的一种成分，在未固化树脂中占近50%w/w，并且是挥发性有机化合物（VOC）。苯乙烯是一种致癌物（NTP 2015），其气味检测限为0.16 ppm。蒸汽养护现浇管由于其成本低，是目前使用的最常见的下水管道和涵洞修复方法之一。建议的工作是迫切需要的，并将提供一个更好的了解固化的现场管道现场的化学气体排放。如果没有这个项目：（1）对现场固化管道安装地点附近的环境和人员造成的风险将继续难以界定，以及（2）城市、公用事业和州运输机构无法实施最佳保护环境或人类健康的工程控制。该项目是为了满足全国各地市政当局，公用事业和运输机构的科学需求，他们正在恢复恶化的水基础设施，特别是管道和涵洞。在美国各地，越来越多地安装现场固化管，用于雨水涵洞和下水道管道修复应用。新的证据表明，现场固化管道安装活动可能会向空气中排放有害的空气污染物苯乙烯，以及其他挥发性有机化合物，超过工作场所接触标准，最常见的是现场固化管道排放控制不力。目前，没有可靠的数据集的时间分辨和挥发性有机化学物质的排放量，从固化的现场管道网站。鉴于越来越多的应急反应事件和人口健康的影响所引发的固化就地管道的化学品排放，有迫切需要拟议的研究。公用事业、城市和州交通机构没有必要的信息来制定施工规范和工程控制策略，以限制现场固化管道站点的化学气体排放。研究结果将填补一个知识空白，这一空白阻碍了基础设施所有者和管理者更好地保护环境和附近居民免受化学气体排放的影响。该项目为普渡大学的学生提供了一个特殊的STEM学习机会。

1624183WheltonCities and utilities across North America are repairing millions of miles of crumbling sewer pipes using the cured-in-place-pipe "trenchless" renewal technique. At the same time, state transportation agencies across the nation are also relying on CIPP for repairing millions of miles of stormwater culverts. The cured-in-place-pipe repair method involves the installation of a resin impregnated fabric into the deteriorating pipeline or culvert followed by curing in situ with heat (hot water or steam) or ultraviolet light. Cured-in-place-pipe is created by the crosslinking of a polymer resin. Evidence indicates that chemical emissions from steam and hot water cured cured-in-place-pipe sewer pipe repair activities can pose a risk to human health and the environment. The project goal is to understand chemical air emissions from steam cured cured-in-place-pipe installations, one of the most popular cured-in-place-pipe technologies.A December 2015 chemical emission study of three steam cured cured-in-place-pipe installation sites in a U.S. city indicated styrene was emitted into the air at greater than 1,000 ppm, exceeding all regulatory workplace exposure standards. Levels reported far exceeded the International Toxicity Estimates for Risk value of 20 ppm for the most susceptible population such as children. Styrene is one ingredient of steam cured cured-in-place-pipe, nearly 50% w/w in the uncured resin, and a volatile organic compound (VOC). Styrene, a carcinogen (NTP 2015), has an odor detection limit of 0.16 ppm. Steam cured cured-in-place-pipe is one of the most common sewer pipe and culvert repair methods in use today due to its low cost. The proposed work is urgently needed and will provide a better understanding of cured-in-place-pipe site chemical air emissions. Without this project: (1) risks posed to the environment and persons near cured-in-place-pipe installation sites will continue to be poorly defined, and, (2) cities, utilities, and state transportation agencies cannot implement engineering controls that best protect the environment or human health. This project is in response to the scientific needs of municipalities, utilities, and transportation agencies across the nation who are rehabilitating deteriorated water infrastructure, specifically pipelines and culverts. Cured-in-place-pipe is increasingly being installed throughout the U.S. for stormwater culvert and sewer pipe repair applications. New evidence suggests that cured-in-place-pipe installation activity can emit the hazardous air pollutant styrene, among other volatile organic compounds into the air exceeding workplace exposure standards and it is most common that cured-in-place-pipe emissions are poorly controlled. Currently, there is no reliable data set of time-resolved and volatile organic chemical species emissions from cured-in-place-pipe sites. In light of the growing number of emergency response incidents and population health impacts prompted by cured-in-place-pipe chemical emissions, there is an urgent need for the proposed study. Utilities, cities, and state transportation agencies do not have the information needed to develop construction specifications and engineering control strategies that limit chemical air emissions from cured-in-place-pipe sites. Results will fill a knowledge-gap that inhibits infrastructure owners and managers from better protecting the environment and nearby population from chemical air emissions. This project provides an exceptional STEM learning opportunity for Purdue University students.