Kinetic Model of Denitrification Process with Nitrite Accumulation

Abstract:

In order to provide theoretical basis for optimal selection of carbon sources,kinetics of denitrification process with sodium acetate and fresh leachate as external carbon source were studied respectively in this paper.When nitrite accumulation occurred temperately in the system,piecewise zeroorder kinetic model and dynamic model based on Monod equations were both used to describe the experimental data,and related parameters were analyzed.Results show that the denitrification rate of the initial phase with sodium acetate as carbon source was 38% higher than that with fresh leachate.Apparent C/N obtained from piecewise kinetic model indicates that nitrite degradation is the limiting step of denitrification process and carbon deficiency may cause nitrite accumulation permanently.Variations of nitrate and nitrite during denitrification process with both external carbon sources can be well described by differential equations model based on Monod equations,and the efficiency of carbon source can be determined by the kinetic parameters obtained.

Key words:denitrification; carbon source; nitrite accumulation; kinetic model