TY - JOUR
T1 - Performance of a constructed wetland with a sulfur/limestone denitrification section for wastewater nitrogen removal
AU - Bezbaruah, Achintya N.
AU - Zhang, Tian C.
PY - 2003/4/15
Y1 - 2003/4/15
N2 - The effectiveness of a nonvegetated lab-scale subsurface flow constructed wetland for wastewater treatment had been evaluated with the feed ammonium concentration of ∼20-40 mg of NH4+-N L-1 and a hydraulic retention time of ∼ 10 d. The present system had a nitrification zone plus a sulfur/limestone (S/L) autotrophic denitrification zone followed by an anaerobic polishing zone and was operated with and without aeration. The wetland had only 80% organics removal and no net nitrogen removal when there was no artificial aeration. However, almost 100% organics removal and ∼81 -90% total inorganic nitrogen (TIN = NH4+-N + NO2-N + NO3--N) removal were achieved when the oxic zone of the system was aerated with compressed air. S/L autotrophic denitrification contributed 21-49% of total NO3--N removal across the whole wetland and 50-95% across the S/L column. TIN and NH4+-N in the effluent were always <5.5 and < 0.7 mg L-1, respectively, when the feed had NH4+-N ≤ 35 mg L-1. Sulfate removal of ∼53-69% was achieved in the anaerobic polishing zone. The position of the S/L column was changed (1.78, 2.24, and 2.69 m from the inlet), and no remarkable difference in nitrogen removal was observed. However, without the S/L column, TIN removal decreased to ∼74%, and the effluent NO3-N increased about two times (9.13 mg of N L-1). The present study has demonstrated the possible use of S/L autotrophic denitrification for nitrate removal in a constructed wetland.
AB - The effectiveness of a nonvegetated lab-scale subsurface flow constructed wetland for wastewater treatment had been evaluated with the feed ammonium concentration of ∼20-40 mg of NH4+-N L-1 and a hydraulic retention time of ∼ 10 d. The present system had a nitrification zone plus a sulfur/limestone (S/L) autotrophic denitrification zone followed by an anaerobic polishing zone and was operated with and without aeration. The wetland had only 80% organics removal and no net nitrogen removal when there was no artificial aeration. However, almost 100% organics removal and ∼81 -90% total inorganic nitrogen (TIN = NH4+-N + NO2-N + NO3--N) removal were achieved when the oxic zone of the system was aerated with compressed air. S/L autotrophic denitrification contributed 21-49% of total NO3--N removal across the whole wetland and 50-95% across the S/L column. TIN and NH4+-N in the effluent were always <5.5 and < 0.7 mg L-1, respectively, when the feed had NH4+-N ≤ 35 mg L-1. Sulfate removal of ∼53-69% was achieved in the anaerobic polishing zone. The position of the S/L column was changed (1.78, 2.24, and 2.69 m from the inlet), and no remarkable difference in nitrogen removal was observed. However, without the S/L column, TIN removal decreased to ∼74%, and the effluent NO3-N increased about two times (9.13 mg of N L-1). The present study has demonstrated the possible use of S/L autotrophic denitrification for nitrate removal in a constructed wetland.
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U2 - 10.1021/es020912w
DO - 10.1021/es020912w
M3 - Article
C2 - 12731855
AN - SCOPUS:0037446579
VL - 37
SP - 1690
EP - 1697
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 8
ER -