The role of chloramine species in NDMA formation

dc.creatorSelbes, Meric
dc.creatorBeita Sandí, Wilson
dc.creatorKim, Daekyun
dc.creatorKaranfil, Tanju
dc.date.accessioned2018-06-12T21:38:02Z
dc.date.available2018-06-12T21:38:02Z
dc.date.issued2018-09
dc.date.updated2018-06-05T22:58:33Z
dc.description.abstractN-nitrosodimethylamine (NDMA), a probable human carcinogen disinfection by-product, has been detected in chloraminated drinking water systems. Understanding its formation over time is important to control NDMA levels in distribution systems. The main objectives of this study were to investigate the role of chloramine species (i.e., monochloramine and dichloramine); and the factors such as pH, sulfate, and natural organic matter (NOM) influencing the formation of NDMA. Five NDMA precursors (i.e., dimethylamine (DMA), trimethylamine (TMA), N,N-dimethylisopropylamine (DMiPA), N,N-dimethylbenzylamine (DMBzA), and ranitidine (RNTD)) were carefully selected based on their chemical structures and exposed to varying ratios of monochloramine and dichloramine. All amine precursors reacted relatively fast to form NDMA and reached their maximum NDMA yields within 24 h in the presence of excess levels of chloramines (both monoe and dichloramine) or excess levels of dichloramine conditions (with limited monochloramine). When the formation of dichloramine was suppressed (i.e., only monochloramine existed in the system) over the 5 day contact time, NDMA formation from DMA, TMA, and DMiPA was drastically reduced (~0%). Under monochloramine abundant conditions, however, DMBzA and RNTD showed 40% and 90% NDMA conversions at the end of 5 day contact time, respectively, with slow formation rates, indicating that while these amine precursors react preferentially with dichloramine to form NDMA, they can also react with monochloramine in the absence of dichloramine. NOM and pH influenced dichloramine levels that affected NDMA yields. NOM had an adverse effect on NDMA formation as it created a competition with NDMA precursors for dichloramine. Sulfate did not increase the NDMA formation from the two selected NDMA precursors. pH played a key role as it influenced both chloramine speciation and protonation state of amine precursors and the highest NDMA formation was observed at the pH range where dichloramine and deprotonated amines coexisted. In selected natural water and wastewater samples, dichloramine led to the formation of more NDMA than monochloramine.es_ES
dc.description.procedenceUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA)es_ES
dc.description.procedenceUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químicaes_ES
dc.description.sponsorshipNational Science Foundation/[CBET 106657]/NSF/Estados Unidoses_ES
dc.identifier.citationhttps://www.sciencedirect.com/science/article/pii/S0043135418303233?via%3Dihub#!
dc.identifier.doi10.1016/j.watres.2018.04.033
dc.identifier.ismn0043-1354
dc.identifier.urihttps://hdl.handle.net/10669/74902
dc.language.isoen_USes_ES
dc.relation.ispartof
dc.rightsacceso embargado
dc.sourceWater Research, Vol 140, pp 100-109es_ES
dc.subjectNDMAes_ES
dc.subjectChloraminationes_ES
dc.subjectMonochloraminees_ES
dc.subjectDichloraminees_ES
dc.subjectDisinfection by-productses_ES
dc.subjectFormation kineticses_ES
dc.subject628.166 Tratamiento químicoes_ES
dc.titleThe role of chloramine species in NDMA formationes_ES
dc.typeartículo original

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