亚硝酸积累条件下反硝化脱氮过程动力学模型

Kinetic Model of Denitrification Process with Nitrite Accumulation

摘要:

采用序批式反应器,对以乙酸钠和新鲜生活垃圾沥滤液为外加碳源的反硝化系统进行了反硝化过程动力学研究,为优选碳源提供理论依据.在系统亚硝酸盐暂时积累条件下,分别采用分段零级动力学模型和基于Monod方程的动态模型,拟合试验数据,并求算相应的动力学参数.结果表明,乙酸钠碳源系统反应初始阶段,脱氮速率要比以垃圾沥滤液为碳源高出38％.分段动力学得到的表观碳氮比(速率比)表明,亚硝酸盐降解阶段是反硝化的限制步骤.基于Monod方程的微分方程组模型,能够很好地拟合两种不同碳源条件下反硝化过程硝酸盐、亚硝酸盐质量浓度的

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.