中文摘要：

通过对水厂各处理工艺单元、供水管网及余氯静态衰减试验中BDOC浓度、余氯及细菌总数等指标的变化分析，提出BDOC浓度在整个供水系统中的变化分为8个阶段，依次为氧化增长期I、工艺去除期、氧化增长期Ⅱ、氧化降低期I、氧化降低期Ⅱ、生物降解期I、生物降解期Ⅱ和生物增长期，分析了各阶段的变化规律和原因，同时指出在整个供水系统中BDOC浓度会出现三个高峰期，分别位于预加氯区、出厂水区和滞水区。

英文摘要：

Through analyzing the variations of BDOC, residual chlorine and total bacterial count in water treatment processes, water distribution system and static decay experiments of residual chlorine, the BDOC variation course in water supply system is divided into eight stages, the sequence of which is oxidation increase stage I , process removal stage, oxidation increase stage Ⅱ, oxidation decrease stage I , oxidation decrease stage Ⅱ, biodegradation stage I , biodegradation stage Ⅱ and biological increase stage. At the same time, the variation regularities and reasons of different stages are analyzed. It is point- ed out that three peak periods of BDOC concentration occur in water supply system, and they exist in prechlorinated water, finished water and stagnant water respectively.