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Effect of Dissolved Oxygen Concentration on Nitrite Accumulation in Nitrifying Sequencing Batch Reactor
Author(s) -
Sánchez Omar,
Bernet Nicolas,
Delgenès JeanPhilippe
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 - 10.2175/106143007x175807
Subject(s) - nitrite , sequencing batch reactor , nitrification , chemistry , ammonium , oxygen , ammonia , bioreactor , nitrogen , activated sludge , mass transfer coefficient , batch reactor , continuous stirred tank reactor , mass transfer , nitrate , environmental chemistry , environmental engineering , chromatography , wastewater , biochemistry , organic chemistry , catalysis , engineering
A mathematical model based on Activated Sludge Model No. 3 (International Water Association, London) and laboratory‐scale experiments were used to investigate ammonia conversion by nitrification in a sequencing batch reactor (SBR). The purpose of the study was to assess the effect of dissolved oxygen concentration on nitrite accumulation in the SBR. As the dissolved oxygen concentration in the SBR depends on the balance between oxygen consumption and oxygen transfer rates, ammonium conversion was measured for different air flowrate values to obtain different dissolved oxygen concentration profiles during the cycle. The ammonia concentration in the feeding medium was 500 mg ammonium as nitrogen (N‐NH 4 + )/L, and the maximum nitrite concentration achieved during a cycle was approximately 50 mg nitrite as nitrogen (N‐NO 2 )/L. The air flow supplied to the reactor was identified as a suitable parameter to control nitrite accumulation in the SBR. This identification was carried out based on experimental results and simulation with a calibrated model. At a low value of the volumetric mass‐transfer coefficient ( k L a ), the maximum nitrite concentration achieved during a cycle depends strongly on k L a , whereas, at a high value of k L a , the maximum nitrite concentration was practically independent of k L a .