4th UF Water Institute Symposium Abstract

Submitter's Name Jiexuan Luo
Session Name Poster Session: Water quality protection and treatment
Poster Number 53
Author(s) Jiexuan Luo,  University of Florida (Presenting Author)
  George Hochmuth,  University of Florida
  Mark Clark, University of Florida
  Nitrogen Loadings from Different Land Uses at University of Florida Determined by High-Resolution in situ Nitrate Sensors
  Export of nitrogen from different watersheds across the United States is receiving increasing attention due to the impairment of water quality in receiving water bodies. Researchers have indicated that different land uses exerted a substantial influence on the water quality. Nitrogen loadings based on different land uses are being studied in many ecosystems, such as the Baltimore, Maryland Ecosystem and Phoenix, Arizona Ecosystem, but few focus in a smaller scale which can be better at identifying the specific nitrogen sources. A nitrogen budget is being developed for the University of Florida campus in Gainesville, FL. This study will use in situ nitrate sensors to collect continuous nitrate data, which will bring new tool to the interpretation of watershed hydrology and biogeochemical processes. The study areas include three sub-basins on the campus with different types of land uses (recreational with intensive fertilization management, urban with reclaimed water irrigation, urban without irrigation) in the Lake Alice watershed. The study will include the outfall point in Lake Alice where the flow discharges to the groundwater. Two in-situ nitrate sensors (SUNAs) are being deployed in different types of land uses each time for a week period taking NO3--N readings every 15 minutes. Continuous time series data will be compared to determine if the storm water NO3--N concentration from one land use is different from another land use. The weekly N loads are calculated as the summation of the products of daily average concentrations and daily average flow over a week. The results showed the weekly time series of NO3--N concentrations in the recreational land use are significantly higher than that from urban with reclaimed water irrigation and from urban without irrigation. The calculated N loads were greater from the recreational land use compared with the two urban areas.