Dissolved Oxygen Control for Activated Sludge Processes

QFT Robust Control of Wastewater Treatment Processes

“…Based on ASM1 model in (Brdys et al, 2001a) a non-linear predictive control technique for the indirect control of organic substrate through the control of dissolved oxygen concentration has been used. For the same model (Brdys et al, 2001b) proposes a hierarchic control structure. This structure contains three levels: a higher level where a stable trajectory for the process on a time horizon is calculated, a mean level where the optimization of the trajectories for dissolved oxygen concentration, the recycled www.intechopen.com activated sludge flow and the recycled nitrate flow takes place and the lower level where the control of dissolved oxygen concentration based on the setpoint imposed by the mean level is done.…”

Nonlinear PI control for dissolved oxygen tracking at wastewater treatment plant

“…A neural-fuzzy algorithm was developed in (Rodrigo et al, 1999) in order to apply gain scheduling for standard PID controller. The nonlinear predictive control was proposed by Brdys and Konarczak (2001) for the removal of nitrogen and phosphorus and further developed in (Chotkowski et al, 2005). A hierarchical predictive two -level controller for the optimised DO tracking was recently presented in (Piotrowski et al, 2007) Due to a mixed integer structure of the aeration system blowers a hybrid model predictive controller (MPC) at the lower control level has been derived in (Piotrowski et al, 2007).…”

Two - Level Dissolved Oxygen Control for Activated Sludge Processes

“…In this paper a design of the lower level controller that allows tracking the robustly optimised dissolved oxygen concentration (DOC) trajectory prescribed by the higher control level is considered. The DO control design was considered in (e.g., Haarsma and Keesman, 1995;Olsson and Newell, 1989;Lindberg andCarlsson, 1966 andKonarczak, 2001). A model predictive control based on linearised model of the DO dynamics was first considered by Haarsma and Keesman (1995).…”

“…A model predictive control based on linearised model of the DO dynamics was first considered by Haarsma and Keesman (1995). Nonlinear model reference adaptive control and nonlinear predictive control was investigated by Brdys and Konarczak (2001) for the nitrogen and phosphorus removal showing an excellent performance of the predictive controllers. A fuzzy model predictive controller that is based on piecewise linearisation is proposed in the accompanying paper (Brdys and Díaz-Maíquez, 2002).…”

“…The upper level control unit produces desired set points of the aeration flow. The nonlinear model predictive algorithm proposed by Brdys and Konarczak (2001) is applied to design this controller unit. Also, the predictive control algorithm is used to design the lower level control unit based on a linearised hybrid dynamics of the aeration process.…”