Factors affecting the water odor caused by chloramines during drinking water disinfection

An-Qi Wang; Yi-Li Lin; Bin Xu; Chen-Yan Hu; Ze-Chen Gao; Zhi Liu; Tong-Cheng Cao; Nai-Yun Gao

doi:10.1016/j.scitotenv.2018.05.188

Factors affecting the water odor caused by chloramines during drinking water disinfection

Sci Total Environ. 2018 Oct 15:639:687-694. doi: 10.1016/j.scitotenv.2018.05.188. Epub 2018 May 26.

Authors

An-Qi Wang¹, Yi-Li Lin², Bin Xu³, Chen-Yan Hu⁴, Ze-Chen Gao⁵, Zhi Liu⁵, Tong-Cheng Cao⁶, Nai-Yun Gao⁵

Affiliations

¹ 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.
² Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 824, Taiwan, ROC.
³ 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. Electronic address: tjwenwu@tongji.edu.cn.
⁴ College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, PR China.
⁵ 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.
⁶ School of Chemical Science and Engineering, Tongji University, Shanghai 200092, PR China.

PMID: 29803040
DOI: 10.1016/j.scitotenv.2018.05.188

Abstract

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, Cl₂/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 Cl₂/N molar ratio of 0.6 or NOM concentration <2 mg-C L^-1 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.

Keywords: Dichloramine; Drinking water odor; Flavor profile analysis; Monochloramine decay.

MeSH terms

Chloramines / analysis*
Disinfection / methods
Drinking Water / chemistry*
Odorants*
Water Purification / methods*

Substances

Chloramines
Drinking Water