中文摘要：

为研究大型环状管网中余氯衰减和三卤甲烷（THMs）的生成模型，在占地570m2的大型中试环状管网中进行。研究温度、初始余氯浓度和总有机碳（TOC）变化条件下对余氯衰减和三卤甲烷生成的影响。根据接近实际管网的中试实验数据，发现温度对余氯衰减的影响最为明显，其次是水中的总有机碳，影响最小的是初始余氯浓度。比较主体水余氯衰减和管壁余氯衰减在不同温度影响下的变化。研究结果表明：随着温度升高，管壁余氯衰减系数基本不变，而主体水中的余氯衰减系数逐渐增加。此外，确定三卤甲烷生成潜能（THMsformationpotential，THMFP）与较易检测指标总有机碳（TOC）浓度之间的关系，并在此基础上结合优化的余氯衰减模型，建立能较好拟合实验数据的三卤甲烷生成模型。由于模型是基于大型环状管网的实验数据并考虑实际温度、TOC浓度和初始余氯浓度变化的影响，使优化的余氯衰减模型和三卤模型具有更好的适用性。

英文摘要：

In order to study chlorine decay model and THMs （trihalomethanes） formation model in the pilot-scale water distribution system, experiments were carried out in the pilot-scale distribution system with 570 m2 area. The effects of temperature, TOC and initial concentration of residual chlorine on chlorine decay and THMs formation were investigated. The experimental results show that the effect of temperature on chlorine decay is the greater than TOC and the initial concentration of residual chlorine. The effect of initial concentration of residual chlorine on chlorine decay is the smallest. With the increase of the temperature, the wall decay is almost same and bulk decay increases. In addition, the relationship between THMs formation potential （THMFP） and TOC is decided. THMs model is built based on the chlorine decay model and the relationship between THMFP and TOC. The kinetic model of chlorine decay and THMs formation model describe experiment data of pilot-scale water distribution system very well. Then the chlorine decay and THMs formation model have better applicability to water distribution system.