Influence of nitrogen source on NDMA formation during chlorination of diuron.

N-Nitrosodimethylamine (NDMA) is formed during chlorination of water containing the herbicide diuron (N'-(3,4-dichlorophenyl)-N,N-dimethylurea) but formation is greatly enhanced in the presence of ammonia (chloramination). Groundwater impacted by agricultural runoff may contain diuron and relatively high total nitrogen concentrations; this study examines the impact of the nitrogen form (ammonium, nitrite or nitrate) on NDMA formation during chlorination of such waters. NDMA formation during chlorination of diuron increased in the order nitrite<nitrate<ammonium for a given chlorine, nitrogen, and diuron dose. Formation of dichloramine seemed to fully explain enhanced NDMA formation in the presence of ammonium. Nitrate unexpectedly enhanced nitrosation of diuron derivatives to form NDMA compared to the cases of no added nitrogen or nitrite addition. Nitrite addition is less effective because it consumes more chlorine and produces intermediates that react rapidly with diuron and its aromatic byproducts. Differences between surface water and groundwater in nitrogen forms and concentrations and disinfection approaches suggest strategies to reduce NDMA formation should vary with drinking water source.

[1]  S. Capasso,et al.  Kinetics of the chemical degradation of diuron. , 2002, Chemosphere.

[2]  R. Thauer,et al.  Energy conservation in chemotrophic anaerobic bacteria , 1977, Bacteriological reviews.

[3]  Debra W. Johnson,et al.  Non‐Metal Redox Kinetics: A Reexamination of the Mechanism of the Reaction Between Hypochlorite and Nitrite Ions. , 1992 .

[4]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[5]  R. Thauer,et al.  Energy Conservation in Chemotrophic Anaerobic Bacteria , 1977, Bacteriological reviews.

[6]  P. Wrona.  Electrode processes of chloramines in aqueous solutions , 1998 .

[7]  N. Cochet,et al.  Environmental impact of diuron transformation: a review. , 2004, Chemosphere.

[8]  D. W. Margerum,et al.  Water chlorination chemistry: nonmetal redox kinetics of chloramine and nitrite ion. , 1994, Environmental science & technology.

[9]  R. L. Valentine,et al.  Formation of N-nitrosodimethylamine (NDMA) from reaction of monochloramine: a new disinfection by-product. , 2002, Water research.

[10]  M. Soulard,et al.  Diagrams of existence of chloramines and bromamines in aqueous solution , 1981 .

[11]  W. Mitch,et al.  Nitrosamine formation pathway revisited: the importance of chloramine speciation and dissolved oxygen. , 2006, Environmental science & technology.

[12]  M. Deinzer,et al.  Environmental health sciences center task force review on halogenated organics in drinking water , 1978, Environmental health perspectives.

[13]  R. Rhodes Trussell,et al.  N-Nitrosodimethylamine (NDMA) as a Drinking Water Contaminant: A Review , 2003 .

[14]  R. L. Valentine,et al.  A kinetic model of N-nitrosodimethylamine (NDMA) formation during water chlorination/chloramination. , 2002, Water science and technology : a journal of the International Association on Water Pollution Research.

[15]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater. 19th ed. 1995. , 1995 .

[16]  David L. Sedlak,et al.  Precursors of N-Nitrosodimethylamine in Natural Waters , 2003 .

[17]  R. L. Valentine,et al.  N-nitrosodimethylamine formation by free-chlorine-enhanced nitrosation of dimethylamine. , 2003, Environmental science & technology.

[18]  R. L. Valentine,et al.  Mechanistic studies of N-nitrosodimethylamine (NDMA) formation in chlorinated drinking water. , 2002, Journal of environmental monitoring : JEM.

[19]  B. Ruddy,et al.  Probability of nitrate contamination of recently recharged groundwaters in the conterminous United States. , 2002, Environmental science & technology.

[20]  T. Young,et al.  NDMA formation during chlorination and chloramination of aqueous diuron solutions. , 2008, Environmental science & technology.

[21]  J. H. Boyer.  Increasing the index of covalent oxygen bonding at nitrogen attached to carbon , 1980 .

[22]  W. Lapham,et al.  Introduction to the U.S. Geological Survey National Water-Quality Assessment (NAWQA) of ground-water quality trends and comparison to other national programs. , 2008, Journal of environmental quality.

[23]  David L Sedlak,et al.  Formation of N-nitrosodimethylamine (NDMA) from dimethylamine during chlorination. , 2002, Environmental science & technology.

[24]  David L Sedlak,et al.  A N-Nitrosodimethylamine (NDMA) precursor analysis for chlorination of water and wastewater. , 2003, Water research.

[25]  Dc Washington,et al.  USEPA. Reregistration Eligibility Decision (RED): 738‐R‐99‐004. United States Environmental Protection Agency, Prevention, Pesticides and Toxic Substances (7508C): 337 pp. , 1999 .