MBR污水处理工艺中活性污泥动力学参数测定

缺乏可靠的污泥动力学设计参数是膜-生物反应器（membrane bioreactor，MBR）工艺在实际应用中遇到的主要问题之一.以某座处理城市污水的实际规模MBR工程的好氧活性污泥为对象，采用耗氧速率表征方法，测定计算得到以下动力学参数值：异养菌产率系数Y_H＝0.693、自养菌产率系数Y_A＝0.263、异养菌衰减系数K_dH＝0.108 d^-1、自养菌衰减系数K_dA＝0.089 d^-1、COD最大比去除速率v_mS＝1.94 mg·(mg·d)^-1、COD去除半饱和常数K_S＝34.6 mg·L^-1、氨氮最大比去除速率v_mN＝0.18 mg·(mg·d)^-1、氨氮去除半饱和常数K_N＝1.06 mg·L^-1.以上结果与传统活性污泥法工艺（CAS）中污泥的文献报道值相比，Y_H和K_dH较高，而v_mS和v_mN较低.MBR的高污泥浓度条件可能是导致上述差异出现的主要原因.

Determination of Kinetic Parameters of Activated Sludge in an MBR Wastewater Treatment Plant

One of the main problems in application of MBR technology is lack of reliable kinetic parameters for process design. The activated sludge in the aerobic tank of an MBR municipal wastewater treatment plant was investigated therefore. Using oxygen utilization rate method, following kinetic parameters were measured: heterotrophic yield coefficient Y_H=0.693, autotrophic yield coefficient Y_A=0.263, heterotrophic decay coefficient K_dH=0.108 d^-1, autotrophic yield coefficient K_dA=0.089 d^-1, specific maximum COD removal rate v_mS=1.94 mg·(mg·d)^-1, half saturation constant for COD removal K_S=34.6 mg·L^-1, specific maximum ammonia removal rate v_mN=0.18 mg·(mg·d)^-1, half saturation constant for ammonia removal K_N=1.06 mg·L^-1. Compared with the normal reported data of conventional activated sludge process (CAS), Y_H, K_dH obtained are higher and v_mS, v_mN are lower. The high sludge concentration condition of MBR process may account for those differences.