AwwaRF和美国环境保护局（USEPA）赞助的这项研究调查了影响形成的因素 以及在实际配电系统条件下消毒副产物（DBPs）的衰变。全面的 配电系统抽样为期一年，在两个免费地点进行 氯化系统和两个氯胺化系统。此外，一个氯胺化系统 定期切换到游离氯进行硝化控制，之前受到了密切监控， 在更换消毒剂期间和之后。监测参数包括四种三卤甲烷 （THM4）、九种卤乙酸（HAA9）和N-亚硝二甲胺（NDMA），以及一套 一般水质参数。本手稿介绍了在实验室获得的THM4和HAA9结果 参与的公用设施，以及对影响形成和衰变的观察因素的讨论 在全尺寸配电系统中使用DBP。 正如预期的那样，温暖月份的THM4和HAA9浓度高于寒冷月份 在游离氯化和氯胺化系统中的寒冷月份。在自由氯化环境中 系统中，THM4浓度随着水龄的增加而增加，余氯减少， 在所有取样中观察到的趋势。在氯胺化系统中，THM4浓度随着水龄的增加而相对稳定 增加。在游离氯化和氯胺化系统中，均未观察到管道材料和直径 影响THM4和HAA9浓度和物种形成。 定期切换到游离氯的氯胺化系统允许确认 几种趋势:THM4和HAA9浓度随水温升高而增加， 尽管温度导致HAA9浓度增加的幅度没有那么高 随着THM4浓度的增加；在试验期间，THM4和HAA9浓度较高 游离氯化期比氯胺化期短； THM4和HAA9 当游离氯被用作最终产物时，浓度随着水龄的增加而增加 消毒剂，而DBP浓度在氯胺化期间保持相对一致；氯化过程中HAA9浓度的增加幅度小于 观察到THM4增加。包括数字。

This AwwaRF and U.S. Environmental Protection Agency (USEPA) sponsored research study investigated factors affecting the formation and decay of disinfection byproducts (DBPs) under actual distribution system conditions. Fullscale distribution system samplings were conducted over a one-year period at two free chlorinated systems and two chloraminated systems. In addition, one chloraminated system, with periodical switches to free chlorine for nitrification control, was closely monitored before, during, and after the disinfectant change. Monitoring parameters included the four trihalomethanes (THM4), the nine haloacetic acids (HAA9) and N-nitrosodimethylamine (NDMA), along with a suite of general water quality parameters. This manuscript presents THM4 and HAA9 results obtained at the participating utilities, and a discussion of observed factors affecting the formation and decay of DBPs in full-scale distribution systems. As expected, THM4 and HAA9 concentrations were higher in the warmer months than in the colder months in both free chlorinated and chloraminated systems. In the free chlorinated systems, THM4 concentrations increased as water age increased and chlorine residual decreased, a trend observed for all samplings. In the chloraminated systems, THM4 concentrations were relatively stable as water age increased. In both free chlorinated and chloraminated systems, pipe material and diameter was not observed to affect THM4 and HAA9 concentration and speciation. The chloraminated systems that periodically switch to free chlorine allowed confirmation of several trends: THM4 and HAA9 concentrations increased with increasing water temperature, although the magnitude of increase in HAA9 concentrations due to temperature was not as high as the increase in THM4 concentrations; THM4 and HAA9 concentrations were higher during the free chlorination period than during the chloramination periods; THM4 and HAA9 concentrations increased with increasing water age when free chlorine was used as final disinfectant, whereas DBP concentrations remained relatively uniform during chloramination; and, the magnitude of increase in HAA9 concentration during chlorination was less than the increase observed for THM4. Includes figures.