N-Nitrosamines are a group of contaminants of public health concern. Current focus on N-nitrosamines in drinking water systems has forced the impression that N-nitrosamines are disinfection byproducts. However, other upstream processes, especially wastewater treatment plants, can serve as direct sources of N-nitrosamines. Numerous studies have documented the fate of volatile N-nitrosamines (e.g., <i>N</i>-nitrosodimethylamine) at conventional and advanced wastewater treatment plants (WWTPs), but these species only represent a small fraction of the total N-nitrosamine (TONO) pool. Very limited information exists pertaining to the identities of unknown nitrosamines in the TONO pool. To fill the gaps in our understanding of the unknown fraction of TONO, we developed a suspect screening workflow based on liquid chromatography-high resolution mass spectrometry (LC-HRMS) and analyzed TONO extracts of 24-h composite samples collected from conventional WWTPs.  Several suspect N-nitrosamines with high detection frequencies have been tentatively identified, including the N-nitrosation products of pharmaceuticals such as N-nitrosonadolol and N-nitrosoephedrine. We further investigated the N-nitrosamine formation potential (FP) of secondary model amines during chloramination. Among seven tested amine containing pharmaceuticals, five of them generated N-nitrosation products that can be identified by LC-HRMS and TONO assay. These results suggest that the N-nitrosation products of amine containing micropollutants may serve as an important component in TONO pool of wastewater and wastewater-impacted drinking water. Our ongoing work includes the determination of reaction kinetics and mechanisms under different reaction conditions by testing a broader suite of similar compounds.  <br/>

Formation of total and specific nitrosamines from amine containing micropollutants in wastewater

2019 Spring National Meeting

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