Formation of N-nitrosamines from eleven disinfection treatments of seven different surface waters.
Formation of nine N-nitrosamines has been investigated when seven different source waters representing various qualities were each treated with eleven bench-scale disinfection processes, without addition of nitrosamine precursors. These disinfection treatments included chlorine (OCl-), chloramine (NH2Cl), chlorine dioxide (ClO2), ozone (O3), ultraviolet (UV), advanced oxidation processes (AOP), and combinations. The total organic carbon (TOC) of the seven source waters ranged from 2 to 24 mg x L(-1). The disinfected water samples and the untreated source waters were analyzed for nine nitrosamines using a solid phase extraction and liquid chromatography-tandem mass spectrometry method. Prior to any treatment, N-nitrosodimethylamine (NDMA) was detected ranging from 0 to 53 ng x L(-1) in six of the seven source waters, and its concentrations increased in the disinfected water samples (0-118 ng x L(-1)). N-nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMor), and N-nitrosodiphenylamine (NDPhA) were also identified in some of the disinfected water samples. NDPhA (0.2-0.6 ng x L(-1)) was formed after disinfection with OCl-, NH2Cl, O3, and MPUV/OCl-. NMEA was produced with OCl- and MPUV/OCl-, and NMor formation was associated with O3. In addition, UVtreatment alone degraded NDMA; however, UV/ OCl- and AOP/OCl- treatments produced higher amounts of NDMA compared to UV and AOP alone, respectively. These results suggest that UV degradation or AOP oxidation treatment may provide a source of NDMA precursors. This study demonstrates that environmental concentrations and mixtures of unknown nitrosamine precursors in source waters can form NDMA and other nitrosamines.
Zhao
Yuan-Yuan
YY
Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, 10-102 Clinical Sciences Building, University of Alberta, Edmonton, Alberta, Canada T6G 2G3.
Boyd
Jessica M
JM
Woodbeck
Matthew
M
Andrews
Robert C
RC
Qin
Feng
F
Hrudey
Steve E
SE
Li
Xing-Fang
XF
D017606:Chlorine Compounds / Q000737:chemistry; D002853:Chromatography, Liquid; D004203:Disinfection / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry*; D009602:Nitrosamines / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*
D017606:Chlorine Compounds; D009602:Nitrosamines; D010126:Ozone