Managing Global Resources for a Secure Future

2017 Annual Meeting | Oct. 22-25 | Tampa, FL

94-5 Effect of Suspended Sediments on Phosphorus Transport in Bioretention Cells.

See more from this Division: SSSA Division: Urban and Anthropogenic Soils
See more from this Session: Sustainable Soils in Urban Environments-Water, Carbon, Mapping , Assessment and Reclamation II Oral (includes student competition)

Monday, October 23, 2017: 2:35 PM
Tampa Convention Center, Room 32

Hallie Douglas1, Thorsten Knappenberger2, Eve Brantley2 and Julie A. Howe1, (1)Auburn University, Auburn, AL
(2)Crop, Soil and Environmental Sciences, Auburn University, Auburn, AL
Abstract:
Bioretention cells (BRC) are a stormwater practice designed to infiltrate, store, and treat stormwater. These cells help to mitigate stormwater flow volume, flow rate, and remove nutrients. Suspended sediments that are commonly found in stormwater runoff decrease bioretention cell infiltration rates over time, rendering the practice less effective.

Bioretention cells interact with water flow, sediment, and pollutants multi-dimensionally, thus 3-D studies are crucial for understanding their dynamics. The goal of this research was to assess how phosphorus flow is affected in non-clogged, semi-clogged and clogged BRC systems and evaluate if the current maintenance recommendations are sufficient.

 Water was pumped through a 3-D flow cell (62.5 cm x 3 cm x 32.5 cm) and the spatial variability of the filtration media was analyzed. Trial 1 had no additional solids, Trial 2 was a “semi clogged” system with 300 g of solids placed on half of the BRC media surface, and Trial 3 was a “clogged system” with 600 g solids placed on the entire BRC media surface. For each trial, simulated stormwater containing phosphorus fertilizer bound to iron oxides was pumped through the cell. After the stormwater flush, media samples of the cell were taken in a grid formation and analyzed for phosphorus concentration. Correlations between the amount of added solids and location of phosphorus adsorption were made by analyzing the BRC media grid. WCP times drastically increased with increased additions of solids, decreasing the hydraulic conductivity of the system.

See more from this Division: SSSA Division: Urban and Anthropogenic Soils
See more from this Session: Sustainable Soils in Urban Environments-Water, Carbon, Mapping , Assessment and Reclamation II Oral (includes student competition)