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Effect of COD /N ratio on denitrification from nitrite
Author(s) -
Badia Ahmed,
Kim Mingu,
Nakhla George,
Ray Madhumita B.
Publication year - 2019
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 - 10.1002/wer.1005
Subject(s) - nitrite , denitrification , chemistry , environmental chemistry , nitrate , food science , nitrogen , organic chemistry
The objective of this study was to investigate dynamic specific denitrification rates ( SDNR s) from nitrite at various chemical oxygen demand ( COD )/nitrogen (N) ratios using municipal wastewater ( MWW ). A sequencing batch reactor ( SBR ) continuously fed with primary effluent and nitrite solution was operated at hydraulic retention time of 8.4 hr and solids retention time of 26–30 days for 3 months. Influent MWW characteristics varied significantly during the study, that is, 200–810 mg COD /L and 6–80 mgN/L. The SDNR s from the SBR were compared with those determined in four batch reactors using acetate. The SDNR was directly related to COD /N until a maximum SDNR (mg NO 2 –N/mg VSS /day) of 0.07 for MWW and 0.4 for acetate occurred at COD /N ratios of 6 and 13, respectively; beyond this COD /N ratio, SDNR decreased. The biomass yield coefficients (mg VSS /mg COD ) were 0.33 for MWW and 0.51 for acetate. The relationships of SDNR with COD /N and F/M ratios were developed. Practitioner points The optimum carbon dose for denitrification should be determined using acclimatized biomass. Each carbon source should only be dosed at an optimum that maximizes denitrification.