好氧反硝化去除低浓度NO_x的动力学模型研究

Dynamic modeling of removal of low-concentration NO_x by aerobic denitrification

在好氧条件下,对利用生物滴滤塔(bio-trickling filter,BTF)反硝化净化废气中NOx的过程进行了理论模型探讨,并用实验结果进行了验证。在分析NOx在BTF内传质以及生物降解过程的基础上,建立了NOx在气相和生物膜相的质量守恒方程,结合Fick定律和好氧条件下的Monod微生物反应动力学方程,最终得到了NOx在BTF中"吸附-微生物降解"过程的动力学方程。模型计算值与实验结果表明,BTF中好氧反硝化过程为一级反应过程,利用该模型可以较好地模拟进口浓度、停留时间等因素对出口浓度的影响,对实际应用具有指导意义。

Based on the analysis of mass transfer biodegradation process of NOx in the bio-trickling filter（BTF）,the mass conservation equations of NOx in gas phase and biofilm phase were constituted.According to the Fick law and the Monod kinetic equation of bioreaction under aerobic condition,the equations of NOx mass transfer biodegradation process in BTF were obtained.In order to simulate the denitrifying process of NO by using BTF under aerobic conditions,a dynamic model of denitrifying removal of NO in BTF was established,and experiments for verifying the validity of the model proposed were conducted.The results show that the process of aerobic denitrification in BTF is a first-order dynamics reaction,which indicates that the proposed model can well describe the removal process of low-concentration NOx in BTF,and the model can simulate the effect of inlet NOx concentration and empty bed residence time（EBRT） on NOx outlet concentration.