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

1624183惠尔顿北美各地的城市和公用事业公司正在使用就地固化管道的“非开挖”更新技术修复数百万英里破损的下水道管道。与此同时，全国各地的州交通机构也依靠CIPP来修复数百万英里的雨水涵洞。就地固化管道修复方法包括将树脂浸渍织物安装到老化的管道或涵洞中，然后用热（热水或蒸汽）或紫外线进行就地固化。就地固化管是由聚合物树脂交联而成的。有证据表明，蒸汽和热水固化的就地固化管道下水道管道维修活动产生的化学物质排放可能对人类健康和环境构成威胁。该项目的目标是了解蒸汽固化管道装置的化学气体排放情况，这是最流行的固化管道技术之一。2015年12月，一项针对美国城市三个蒸汽固化管道安装地点的化学排放研究表明，苯乙烯排放到空气中的浓度超过1000ppm，超过了所有监管工作场所的暴露标准。报告的水平远远超过国际毒性评估对儿童等最易感人群的风险值20 ppm。苯乙烯是蒸汽固化管的主要成分之一，未固化树脂占比近50%，是一种挥发性有机化合物（VOC）。苯乙烯是一种致癌物（NTP 2015），其气味检测极限为0.16 ppm。蒸汽固化就地固化管由于其成本低，是目前使用的最常用的下水道管道和涵洞修复方法之一。拟议的工作是迫切需要的，并将提供更好地了解就地固化管道现场化学气体排放。如果没有这个项目：(1)对环境和就地固化管道安装地点附近人员构成的风险将继续模糊不清；(2)城市、公用事业和州运输机构无法实施最能保护环境或人类健康的工程控制。这个项目是为了满足全国各地市政、公用事业和运输机构的科学需求，他们正在修复恶化的水利基础设施，特别是管道和涵洞。在美国，越来越多地安装了就地固化管道，用于雨水涵洞和下水道管道的维修。新的证据表明，就地固化管道的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，这些污染物超过了工作场所的暴露标准，而且最常见的是，就地固化管道的排放控制不善。目前，还没有可靠的时间分辨和挥发性有机化学物质排放的数据集。鉴于越来越多的应急事件和由就地处理的管道化学品排放引起的人口健康影响，迫切需要进行拟议的研究。公用事业、城市和州运输机构没有必要的信息来制定施工规范和工程控制策略，以限制就地固化管道现场的化学空气排放。研究结果将填补阻碍基础设施所有者和管理者更好地保护环境和附近人口免受化学气体排放的知识空白。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.