Stormwater road runoff is a widespread non-point source of contaminants such as nutrients, which endangers water bodies, especially in vulnerable karst areas such as Florida. While roadside vegetated filter strips (VFSs) and stormwater basins are generally accepted best management practices (BMPs) for stormwater management, uncertainties about VFS nutrient removal are reported and stormwater basins are concerned of facilitating contaminant transport. In this dissertation, the application and efficacy of engineered infiltration media was tested as a subgrade for the enhanced nutrient removal from roadway runoff. Results of field-scale laboratory testing indicated that a VFS with engineered biosorption activated media (BAM) outperformed a Control with sandy soil concerning nitrate removal (mean 94±6% reduction vs. 23±64% increase) and total nitrogen removal (mean 80±5% vs. 38±23% reduction) within a 6 m filter width. However, BAM and soil performed similarly with respected to total phosphorus removal within the first 1.5 m filter width (84±9% vs. 82±12% reduction). Next, field sampling was conducted to characterize nutrient load and delivery in stormwater road runoff in different events, providing insights to improve design of BMPs. Three types of runoff events were characterized, where nutrients are transported differently under the controls of nutrient supply and transport conditions. Antecedent dry period was strongly related to nutrient supply and runoff volume was correlated to nutrient transport capacity. Finally, the configuration of the subsurface in stormwater basins and runoff movement to and within karst aquifer near Silver Springs in central Florida were investigated using geophysical surveys (ground penetrating radar and frequency domain electromagnetics) and tracer tests. Numerous subsurface anomalies and surface sinkholes were detected in the basins. High groundwater velocities in the surficial aquifer (10-6 to 10-3 ms-1) and Upper Floridan Aquifer (maximum on the order of 10-1 ms-1) indicated that the basins act as hotspots of groundwater contamination in the area.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd2020-2346 |
| Date | 01 January 2021 |
| Creators | Shokri, Mohammad |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations, 2020- |
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