State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 824, Taiwan, ROC.
Sci Total Environ. 2018 Oct 15;639:687-694. doi: 10.1016/j.scitotenv.2018.05.188. Epub 2018 May 26.
Chloramine disinfection is one of the most common disinfection methods in drinking water treatment. In this study, the temporal variability of water odors during monochloramine auto-decomposition was investigated to elucidate the characteristics of odor problems caused by adopting chloramine disinfection in tap water. Odor intensities and dominant odorant contributions were determined using the flavor profile analysis (FPA) and odor active value (OAV), respectively. During auto-decomposition of monochloramine, Cl/N molar ratio, pH, temperature, and the presence of NOM all affected odor intensity and odor temporal variation in drinking water. In general, decreasing pH from 8.5 to 6.0 led to increasing perceived odor intensity due to the formation of dichloramine. The major odorants responsible for chlorinous odor under acidic and non-acidic conditions were dichloramine and monochloramine, respectively. Chloraminated water with a Cl/N molar ratio of 0.6 or NOM concentration <2 mg-C L inhibited odor intensity. Furthermore, the influence of rechlorination on chlorinous odor intensity for chloraminated water should not be neglected. The results of this study will be beneficial for the control of chlorinous odors caused by chloramine disinfection in drinking water.
氯胺消毒是饮用水处理中最常见的消毒方法之一。在这项研究中，研究了单氯胺自动分解过程中水中气味的时间变化，以阐明在自来水中采用氯胺消毒引起的气味问题的特点。使用风味剖面分析（FPA）和气味活度值（OAV）分别确定气味强度和主要气味贡献。在单氯胺自动分解过程中，Cl/N 摩尔比、pH 值、温度和 NOM 的存在均影响饮用水的气味强度和气味时间变化。一般来说，由于二氯胺的形成，将 pH 值从 8.5 降低至 6.0 会导致感知气味强度增加。在酸性和非酸性条件下，产生氯气味的主要气味物质分别为二氯胺和单氯胺。Cl/N 摩尔比为 0.6 或 NOM 浓度<2mg-C·L 的氯胺化水会抑制气味强度。此外，不应忽视氯胺化水的再氯化对氯气味强度的影响。本研究结果将有助于控制饮用水中因氯胺消毒引起的氯气味。
