生物滴滤床降解有机废气净化效率的理论模型

Theoretical model for purification efficiency of organic waste gas in trickling biofilter

将生物膜滴滤塔内的多孔填料简化为壁面覆盖有生物膜的平行平板通道,建立了一个净化低浓度有机废气的理论模型.该模型首先运用两相流理论获得了通道内液膜厚度,然后通过污染物在气相、液相的质量组分方程,结合生物膜内的传质与不考虑氧限制的生化反应动力学方程,获得了污染物在液相和生物膜中浓度分布的近似分析解,最终得到污染物在气相中沿塔高的浓度分布及废气净化效率.模型的理论预测值与生物膜滴滤塔净化低浓度甲苯废气的实验结果基本吻合.

A theoretical model for purification of waste gas of low concentration in trickling biofilter was established with simplifying, the polyhole filter in the trickling biofilter to a parallel plat plates passage covered with biofilm. In the model the film thickness in the passage was obtained at first using two phase flow theory; then, similar analysis solution of concentration distribution of the pollutant in liquid phase and biofilm was obtained through mass component equation of pollutant in gas-liquid phases combined with the biochemical kinetic equation of mass transfer in biofilm and dismission of oxygen limited; at last, the distribution of pollutant along the filter height and the waste gas purification efficiency were obtained. The predicted value of the model theory coincided basically with the experimental result of the waste gas methyl benzene of low concentration in the trickling biofilter.