Water quality improvement through bioretention media: nitrogen and phosphorus removal.
High nutrient inputs and eutrophication continue to be one of the highest priority water quality problems. Bioretention is a low-impact development technology that has been advocated for use in urban and other developed areas. This work provides an in-depth analysis on removal of nutrients from a synthetic stormwater runoff by bioretention. Results have indicated good removal of phosphorus (70 to 85%) and total Kjeldahl nitrogen (55 to 65%). Nitrate reduction was poor (< 20%) and, in several cases, nitrate production was noted. Variations in flowrate (intensity) and duration had a moderate affect on nutrient removal. Mass balances demonstrate the importance of water attenuation in the facility in reducing mass nutrient loads. Captured nitrogen can be converted to nitrate between storm events and subsequently washed from the system. Analysis on the fate of nutrients in bioretention suggests that accumulation of phosphorus and nitrogen may be controlled by carefully managing growing and harvesting of vegetation.
Davis
Allen P
AP
Department of Civil and Environmental Engineering, Maryland Water Resources Research Center, University of Maryland, College Park 20742, USA. apdavis@umd.edu
Shokouhian
Mohammad
M
Sharma
Himanshu
H
Minami
Christie
C
D000383:Agriculture; D017753:Ecosystem; D004784:Environmental Monitoring; D005068:Eutrophication; D005308:Fertilizers; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000302:isolation & purification*; D010758:Phosphorus / Q000302:isolation & purification*; D011891:Rain; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
D005308:Fertilizers; D009566:Nitrates; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen