采用微电极测定球形填料结构对传质过程的影响  

Effect of spherical biocarrier structure on the mass transfer by microelectrode

作　　者：周小红[1] 施汉昌[1] 邱玉琴[1] 

机构地区：[1]清华大学环境科学与工程系环境模拟与污染控制国家重点联合实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2007年第6期834-837,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(50478009);国家"九七三"基础研究基金项目(2005CB724901)

摘　　要：为优化球形生物填料结构设计,研究通心多孔柱体结构对SNPTM型悬浮型球形生物填料传质过程的影响。制备溶解氧微电极,检测沿填料半径方向上的溶解氧分布情况。通过径向溶解氧分布曲线,结合扩散-反应方程拟合获得填料内部溶解氧有效扩散系数。拟合结果表明:填料内部的溶解氧传质属于紊流扩散;在外界条件相同的情况下,堵上通心多孔柱体后溶解氧有效扩散系数降低至原来的65%。通心多孔柱体对传质过程的影响主要体现在沿填料半径方向的内层区域范围内。The effect of the perforated hollow duet structure on the mass transfer in SNPTM spherical bioearriers was studied to optimize the bioearrier structure. A dissolved oxygen mieroeleetrode was constructed to determine the dissolved oxygen profiles along the biocarrier radius. The effective diffusivity coefficient of dissolved oxygen was calculated based on a diffusion-reaction model by curve-fitting the measured dissolved oxygen profiles. The results show that turbulent diffusion is more significant than molecular diffusion in the bioearriers. The calculated effective dissolved oxygen diffusion coefficient decreases by 35% without the hollow duct. The mass transfer in the inner zone of the bioearrier is strongly affected by the hollow duct structure.

关 键 词：传质 微电极 球形生物填料 有效扩散系数 

分 类 号：X505[环境科学与工程—环境工程]