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| Submitter's Name |
Gurpal Toor |
| Session Name |
Sensors and Technologies |
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| Author(s) |
Gurpal Toor, University of Florida (Presenting Author) |
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Yun-Ya Yang,
University of Florida |
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Stefan Kalev, University of Florida |
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Identification of Nitrate-Nitrogen Sources in Residential Stormwater Runoff Using δ15N and δ18O |
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Sources of nitrate-nitrogen (NO3-N) in urban residential neighborhood stormwater retention pond waters may include a combination of atmospheric deposition, fertilizers, organic materials, and soil. In this study, we used N and oxygen (O) stable isotopes of nitrate (δ18O-NO3- and δ15N-NO3-) and δ18O and hydrogen (δD) of water (H2O) to identify the dominant sources of NO3-N from a low-density residential neighborhood. Stormwater samples were collected over 25 events during 2014 wet season (July to September) at 5-min intervals using an autosampler installed at the outlet pipe. Isotopic results from δ15N-NO3 and δ18O-NO3 suggest that both atmospheric deposition and chemical fertilizers contributed NO3-N to urban stormwater runoff. The mechanisms driving NO3-N transport during runoff events were primarily hydrologic and not biogeochemical. We suggest that a better understanding of N evolution and sources in residential catchments is important to reduce N loads and improve water quality in urban waters. |
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