中文摘要：

生物载体内部溶解氧的传质是影响载体同步硝化反硝化性能的重要因素．介绍了一种以溶解氧微电极为测试工具，获得球形生物载体内部溶解氧扩散系数的方法．采用自制的溶解氧微电极检测沿载体半径方向上的溶解氧分布，结合扩散-反应方程拟合获得载体内部的溶解氧有效扩散系数．结果表明，在载体填充率为25％的情况下，连续流球形载体反应器可实现同步硝化反硝化，对有机物的去除负荷达到5．6kg／（m^3·d）．沿载体半径方向里层1/2区域范围内溶解氧消耗为零，载体内能够形成明显的缺氧，厌氧区．溶解氧分布曲线的拟合结果表明，载体内部溶解氧有效扩散系数为O．0172m^2／d，传质过程以紊动传质为主．

英文摘要：

Mass transfer of oxygen inside biocarrier is a key factor determining the performance of simultaneous nitrification and denitrification. Measurement of the effective diffusion coefficient of dissolved oxygen （DO） in a spherical biocarrier was introduced. Based on a diffusion- reaction model, the effective diffusion coefficient of dissolved oxygen （DO） was calculated by curve-fitting the depth distribution of DO measured by microelectrode. At the filling rate of 25 %, simultaneous nitrification and denitrification is achieved in the continuous flow reactor with organic removal loading of 5.6 kg/（m^3·d）. The effective diffusivity coefficient of DO is calculated to be 0.017 2 m^2/d, which means the turbulence diffusion prevailes against the molecular diffusion inside the biocarrier.