title: δ(15)N and δ(18)O Reveal the Sources of Nitrate-Nitrogen in Urban Residential Stormwater Runoff.
abstract: Nitrogen (N) sources are widely distributed in the complex urban environment. High-resolution data elucidating N sources in the residential catchments are not available. We used stable isotopes of N and oxygen (O) of nitrate (δ(18)O-NO3(-) and δ(15)N-NO3(-)) along with δ(18)O and hydrogen (δD) of water (H2O) to understand the sources and transformations of N in residential stormwater runoff. Stormwater runoff samples were collected over 25 stormwater events at 5 min intervals using an autosampler installed at the residential catchment outlet pipe that drained 31 low-density homes with a total drainage area of 0.11 km(2). Bayesian mixing model results indicated that atmospheric deposition (range 43-71%) and chemical N fertilizers (range <1-49%) were the dominant NO3-N sources in the stormwater runoff and that there was a continuum of source changes during the stormwater events. Further, the NO3-N transport in the stormwater runoff from the residential catchment was driven by mixing of multiple sources and biotic (i.e., nitrification) processes. This work suggests that a better understanding of N transport and sources is needed to reduce N export and improve water quality in urban water systems.
authors: Soil and Water Quality Laboratory, Gulf Coast Research and Education Center, University of Florida, Institute of Food and Agricultural Sciences , 14625 CR 672, Wimauma, Florida 33598, United States.
authors: Yun-Ya
authors: YY
authors: Yang
authors: Soil and Water Quality Laboratory, Gulf Coast Research and Education Center, University of Florida, Institute of Food and Agricultural Sciences , 14625 CR 672, Wimauma, Florida 33598, United States.
authors: Gurpal S
authors: GS
authors: Toor
mesh_terms: D001499:Bayes Theorem; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D005308:Fertilizers; D009566:Nitrates / Q000032:analysis; D058465:Nitrification; D009584:Nitrogen / Q000737:chemistry*; D009587:Nitrogen Isotopes / Q000032:analysis; D010100:Oxygen / Q000737:chemistry*; D010103:Oxygen Isotopes / Q000032:analysis; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D005308:Fertilizers; D009566:Nitrates; D009587:Nitrogen Isotopes; D010103:Oxygen Isotopes; D014874:Water Pollutants, Chemical; D009584:Nitrogen; D010100:Oxygen