Effect of cold-temperature shock on nitrification.
Nitrification is known as the most temperature-sensitive step among the biological processes in wastewater treatment. The purpose of this study was to investigate the effect of temperature on nitrification, in the case of a sharp decrease of temperature, and to compare this effect with that of a gradual temperature decrease. It was found that a sudden temperature decrease affected nitrification much more than predicted. The immediate decrease of temperature by 10 degrees C led to a 20% larger decrease of specific nitrification rate than predicted by the temperature correction factor of 1.072. The change of nitrification rate resulting from a gradual temperature decrease was modeled correctly with the current default temperature correction factor of 1.072. It was concluded that the correction factor actually can be applied to a gradual temperature-change situation; however, in the case of a sudden temperature decrease, measures need to be taken to avoid nitrifier washout.
Hwang
Jong Hyuk
JH
Department of Civil Engineering, University of Manitoba, Winnipeg, Manitoba, Canada. umhwang6@cc.umanitoba.ca
Oleszkiewicz
Jan A
JA
D018533:Biomass; D019149:Bioreactors; D003080:Cold Temperature; D007220:Industrial Waste; D009573:Nitrites / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D007220:Industrial Waste; D009573:Nitrites