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Nitrogen Removal from Urban Stormwater Runoff Through Layered Bioretention Columns
Author(s) -
Hsieh Chihsu,
Davis Allen P.,
Needelman Brian A.
Publication year - 2007
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143007x183844
Subject(s) - bioretention , surface runoff , stormwater , nitrification , environmental science , nitrate , environmental engineering , nitrogen , denitrification , environmental chemistry , chemistry , ecology , organic chemistry , biology
Bioretention is a low‐impact technology used for the treatment of stormwater runoff in developed areas. The fates of mineral nitrogen compounds in two bioretention columns (RP1 and RP2) with different media‐layering characteristics were investigated under multiple loadings of simulated urban runoff. The immediate capture of nitrogen was evaluated, with nitrogen transformation reactions that occurred during the drying periods between rainfall events. A greater proportion of ammonium was removed from runoff in RP2 (68 ± 16%), which had a high permeability layer over a lower permeability layer, than in RP1 (12 ± 6%), which had the inverse configuration. Both column systems demonstrated nitrate export (9 ± 32% and 54 ± 22% greater than input for RP1 and RP2, respectively), attributed to washout of nitrate resulting from nitrification processes between runoff loading events. Bioretention media with a less permeable bottom soil layer could form an anoxic/anaerobic zone for promoting nitrification/denitrification processes.