本文总结了美国水务协会研究基金会（AWWARF）赞助的研究结果，以表征和模型在配电系统中的氯衰减。本研究的主要目的是更好地理解描述配水系统中氯衰变和三卤甲烷（THM）形成的动力学关系，并为水务行业提供改进的水质模拟模型。该研究包括一个广泛的现场抽样研究项目，为验证替代动力学模型提供数据。同时，进行了水质参数对氯衰变和层流氯衰变模型影响的实验室研究。使用参与公用事业公司进行的现场抽样研究中收集的数据，对几个动力学模型进行了评估、测试和验证。 这些研究结果表明，在大多数情况下，配水系统中的氯衰变可以被描述为散装液体中的一级衰变，或者是管壁处的一级散装和一级或零级衰变反应的组合。这些动力学模型正在EPANET分配网络模型中实施，EPANET分配网络模型是一个公共领域软件包，由EPA开发和分发，可供水利行业使用。本文的重点是分析美国实地抽样研究的结果以及氯衰变模型的评估和测试。

This paper summarizes the results of an American Water Works Association Research Foundation (AWWARF) sponsored study to characterize and model chlorine decay in distribution systems. The primary goal of this study was to gain a better understanding of the kinetic relationships describing chlorine decay and trihalomethane (THM) formation in water distribution systems and to make available to the water utility industry improved water quality simulation models. The study included an extensive program of field sampling studies to provide data for validating alternative kinetic models. Concurrently, laboratory research on the effect of water quality parameters on chlorine decay and laminar flow chlorine decay models was performed. Several kinetic models were evaluated, tested, and validated using data collected in the field sampling studies conducted at the participating utilities. The results of these studies indicate that chlorine decay in distribution systems can be characterized in most cases as either first order decay in the bulk liquid or as a combination of first order bulk and first or zero order decay reactions at the pipe wall. These kinetic models are being implemented in the EPANET distribution network model, a public domain software package developed and distributed by EPA and available to the water utility industry. The focus of this paper is on the analysis of the results of the US field sampling studies and the evaluation and testing of chlorine decay models.