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Nitrogen and Phosphorus Removal in a Rain Garden Flooded with Wastewater and Simulated Stormwater
Author(s) -
Strong Patrick,
Hudak Paul F.
Publication year - 2015
Publication title -
environmental quality management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.249
H-Index - 27
eISSN - 1520-6483
pISSN - 1088-1913
DOI - 10.1002/tqem.21447
Subject(s) - stormwater , bioretention , environmental science , wastewater , outflow , inflow , phosphorus , hydrology (agriculture) , environmental engineering , surface runoff , nitrogen , nitrate , ecology , chemistry , geography , engineering , geotechnical engineering , organic chemistry , meteorology , biology
Rain gardens, also known as bioretention cells, are low‐impact developments designed to mitigate several problems associated with urban stormwater. This four‐month field study involved a rain garden at a wastewater treatment plant in north‐central Texas in the United States of America. Partially treated wastewater from an anaerobic digester spilled into the rain garden at the beginning of the study. Subsequently, inflow and outflow concentrations of nitrogen and phosphorus were measured for nine simulated floods, preceded by dry‐spell intervals of 5, 8, or 12 days. Despite large inputs from the wastewater spill, the rain garden gradually processed and flushed the nitrogen. Longer dry spells tended to produce relatively higher outflow nitrate concentrations. A large pool of phosphorus in the soil restricted the rain garden's ability to reduce outflow orthophosphate concentrations, which were stable and lower than inflow concentrations throughout the study; however, adsorptive processes attenuated a relatively high inflow concentration by the end of the study.