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Subsurface flow constructed wetlands treating municipal wastewater for nitrogen transformation and removal
Author(s) -
Kemp Michael C.,
George Dennis B.
Publication year - 1997
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 - 10.2175/106143097x126019
Subject(s) - effluent , constructed wetland , wastewater , hydraulic retention time , environmental engineering , subsurface flow , chemistry , zoology , nitrogen , sewage treatment , environmental chemistry , environmental science , biology , geology , geotechnical engineering , organic chemistry , groundwater
Research was conducted on pilot‐scale, subsurface flow constructed wetland systems treating municipal wastewater. Increasing the hydraulic retention time (HRT) from 1.7 days to 4.3 days reduced the mean effluent NH 4 concentration by 2.7 mg N/L. Hydroperiod manipulation caused a 2.9‐mg N/L decrease in effluent NH 4 . The influent NH 4 concentration for the 9‐month study period averaged 21 mg N/L. The lowest average effluent NH 4 concentration observed in single‐stage treatment cells was 13 mg N/L. The mean effluent NH 4 concentration from the second‐stage cells of two wetland cells in series was 10 mg N/L. During the period from May through September, the second‐stage cells produced an effluent NH 4 concentration of 6 mg N/L. A variable‐order kinetic model for sizing the second‐stage cells of a series system yielded a coefficient of determination, r 2 of 0.94 for the summer NH 4 removal data. The predicted HRT to reduce NH 4 from 20 mg N/L to 5 mg N/L was 3.9 days, if the cells were subjected to cyclic draw and fill.