MBR污水处理工艺中活性污泥动力学参数测定

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

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YH=0.693、自养菌产率系数YA=0.263、异养菌衰减系数KdH=0.108 d-1、自养菌衰减系数KdA=0.089d-1、COD最大比去除速率vmS=1.94 mg.(mg.d)-1、COD去除半饱和常数KS=34.6 mg.L-1、氨氮最大比去除速率vmN=0.18mg.(mg.d)-1、氨氮去除半饱和常数KN=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,YH和KdH较高,而vmS和vmN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.

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 YH = 0.693,autotrophic yield coefficient YA = 0.263,heterotrophic decay coefficient KdH = 0.108 d-1,autotrophic yield coefficient KdA = 0.089 d-1,specific maximum COD removal rate vmS = 1.94 mg.（mg.d）-1,half saturation constant for COD removal KS = 34.6 mg.L-1,specific maximum ammonia removal rate vmN = 0.18 mg.（mg.d）-1,half saturation constant for ammonia removal KN = 1.06 mg.L-1.Compared with the normal reported data of conventional activated sludge process（CAS）,YH,KdH obtained are higher and vmS,vmN are lower.The high sludge concentration condition of MBR process may account for those differences.