title: Characterization of pharmaceuticals and personal care products as N-nitrosodimethylamine precursors during disinfection processes using free chlorine and chlorine dioxide.
abstract: The worldwide detection of pharmaceuticals and personal care products (PPCPs) in aquatic environment and drinking water has caused wide concern in recent years. The possibility for concurrent formation of N-nitrosodimethylamine (NDMA) during disinfection has become another significant concern for water quality. This study demonstrates that a group of PPCPs containing amine groups can serve as NDMA precursors during free chlorine or chlorine dioxide (ClO2) chlorination processes. Selected PPCPs after screening by NDMA yield were further investigated for NDMA formation conditions. High disinfectant dose and initial PPCP concentration resulted in relatively high NDMA formation potential. Linear kinetic models were developed for NDMA formation during chlorination of selected PPCPs. Although the PPCP precursors were removed significantly during chlorination, they were not completely mineralized based on the total organic carbon (TOC) loss. The existence of another possible pathway for direct formation of NDMA from tertiary amine during chlorination was indicated, in which dimethylamine (DMA) was not involved. It is recommended to control the initial PPCP concentrations prior to disinfection and to shorten the contact time to reduce the NDMA formation. ClO2 is suggested to be a proper disinfectant in order to reduce the NDMA formation.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, People's Republic of China.
authors.forename: Ai
authors.initials: A
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, People's Republic of China; UNEP-Tongji Institute of Environment for Sustainable Development, People's Republic of China. Electronic address: liyongmei@tongji.edu.cn.
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, People's Republic of China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yang
mesh_terms: D002713:Chlorine / Q000737:chemistry*; D017606:Chlorine Compounds / Q000737:chemistry*; D004128:Dimethylnitrosamine / Q000737:chemistry*; D004203:Disinfection; D010087:Oxides / Q000737:chemistry*
chemical_list: D017606:Chlorine Compounds; D010087:Oxides; D002713:Chlorine; C025109:chlorine dioxide; D004128:Dimethylnitrosamine
keywords: Chlorine dioxide (ClO(2)); Dimethylamine (DMA); Free chlorine; N-nitrosodimethylamine (NDMA); Pharmaceuticals and personal care products (PPCPs)