重力流排水管道内流态对生物膜菌落结构的影响

Impact of flow pattern of drainage pipe on structure of biofilm colonies

为探究排水管内壁面剪切力与生物菌落结构之间的关系,基于排水管道内流态与壁面剪切应力二维回归模型,建立了3套管道生物膜培养装置,利用微电级技术获得了3种不同剪切力条件下生物膜厚度随时间变化规律,结果显示:剪切力分别为1.12、1.29和1.45 Pa时,对应生物膜稳定厚度分别为(2.40±0.15)、(2.70±0.15)和(2.20±0.15)mm。结合高通量测试技术与溶解氧微电级技术研究了不同壁面剪切力对生物膜菌落结构的影响,得出F=1.29 Pa为异养菌最适生长的剪切力,有利于COD的去除,COD去除率达到40.13%。

In order to explore the relationship between the shear stress in drainage pipes and the structure of microbial colonies,three devices were built to cultivate pipe biofilms.This approach is based on previous research involving a two dimensional regression model used to relate wall shear-stress and flow patterns in drainage pipes.The variation of biofilm thickness with time under three different shear-stress conditions was obtained using micro electrode technology.The results showed that when shear stress was 1.12,1.29,and 1.45 Pa,the stable thickness of the respective biofilm was（2.40±0.15）,（2.70±0.15）,and（2.20±0.15） mm.High-throughput testing and dissolved-oxygen micro-electrode techniques were used to study the influence of differences in wall shear stress on the structure of the biofilm colonies.We found that F=1.29 Pa was the optimum shear stress for growth of heterotrophic bacteria beneficial for the removal of COD.Under this condition,the removal rate reached 40.13%.