A. James Clark School of Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/1654
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
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Item IMPACT OF PERIODIC HIGH CONCENTRATIONS OF SALTS ON BIORETENTION NUTRIENTS PERFORMANCE(2018) McManus, Meigan; Davis, Allen P; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Bioretention is a stormwater control measure commonly used to remove pollutants, including nitrogen (N) and phosphorus (P), from urban runoff. This project seeks to evaluate the impacts of high concentrations of sodium chloride (NaCl) deicer on bioretention N and P removal performances. Bioretention mesocosm studies were conducted to examine N and P removal efficiencies following periodic 2,000, 5,000, and 10,000 mg/L NaCl salt applications. Episodic washouts of TSS, N and P, likely due to ion exchange with the sodium and chloride ions, were observed for all three columns and mass export of P was observed for the 2,000 and 5,000 mg/L NaCl columns after 26 m and 7 m applied water, respectively. No mass N export was observed. Based on a mass balance of N and P, it is recommended to limit the use of deicers to prevent long-term P export.Item Relating pollutant and water quality parameters to landuse in a subwatershed in the Choptank River watershed(2010) Nino de Guzman, Gabriela Tejeda; Torrents, Alba; Hapeman, Cathleen J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Agriculture and animal feeding operations have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This survey examined a subwatershed within the Choptank River watershed for impacts of a poultry facility on its adjacent surface water. Water and sediment samples were collected May - October 2009 under mostly baseflow conditions and analyzed for antibiotics, nutrients, heavy metals, and selected bacteria. Of the antibiotics recovered, no significant difference was observed spatially, but a significant difference emerged between spring and fall/winter. For nutrients, the greatest phosphorus concentrations were at the subwatershed outlet (4) and at two branches not containing the poultry house (3 and 5); nitrogen concentrations at sites 2 and 5 were as high as site 4. Arsenic concentrations at 2 were lower than both the low-agriculture (control) site and a site neighboring 3. Bacterial counts in water and sediment remained fairly constant throughout the sampling regime.