Continuous-time identification of a PWM aerated bench scale activated sludge reactor using state-variable filters

In activated sludge systems the dissolved oxygen dynamics have been seen as the main information source for online state estimation. Then, most accurate models for dissolved oxygen can improve the quality of the estimations and consequently of the measurement system. In this paper a bench scale aerobic reactor model is developed by including the dynamics related with the aeration system operation and the dissolved oxygen probe. The aeration system is operated by aquarium air pumps, which must be turned on as needed. The procedure for estimating the model parameters is presented. Simulations are presented for illustrating the proposed model. The parameters are estimated from experimental results using a bench scale reactor developed at the laboratory.