Fault diagnosis system for A2O process of urban sewage based on ASM2 model and expert system

For urban sewage treatment process of A²O, a fault diagnosis method based on parameter estimation of Activated Sludge Model No.2 (ASM2) model and expert system is proposed. Firstly, the A²O process is simulated based on Activated Sludge Model No.2 (ASM2) model, and then according it to calculate the estimated value of components parameter of biochemical reaction process, and compare it with the real value of corresponding parameter which provide auxiliary fault knowledge support for expert system. Furthermore, an expert system can draw fault diagnosis results is designed by means of uncertainty reasoning for expert knowledge based on RETE algorithm, which making full use of priori knowledge to diagnose effective for the fault reasoning. Finally, a fault diagnosis system for A²O process is developed. For a sewage treatment plant of Kunming, experiment result has shown that the fault diagnosis system for A²O process can make effective diagnosis of the actual process issues, and it has certain engineering practicability.