Wastewater Treatment Simulator Development And Water Quality Control Strategy Study

Activated sludge biological treatment process is extensively adopted in current wastewater treatment plant. It's a typical biochemical treatment process, which has characteristic of complicated mechanism. So it's especially essential to guide the operation and control of wastewater treatment plant by simulation.Wastewater treatment process which has features serious disturbance, time delay, nonlinear, and time varying. Also, at present, the key parameters of water quality are difficult to be on-line measured. So wastewater treatment plant can not be automatic adjusted based on effluent quality. Along with increasingly stringent effluent discharge standards, in order to minimize operation cost to achieve set standards for water quality, the implementation of effective monitoring and control strategy in the wastewater treatment plant is particularly important.The main content of this paper is as follows:1,Developing a wastewater treatment plant simulator (WTPS) based on the Benchmark Simulation model issued by International Water Association (IWA). The simulator can be used to simulate typical activated sludge biological treatment process and evaluate the implementation of various control strategies, it also can be used for education and training.2,In order to implement effective control strategies, the effluent water quality should be monitored. But the key parameters of effluent quality can not be on-line measured. For this issue, the soft-sensor model based least-squares support vector regression (LS-SVR) was promoted to forecast the effluent quality of wastewater treatment plant. The estimation of some difficultly to on-line measured parameters such as COD, TN, and BOD is gained by this model.3,To achieve effective removal of pollutants, wastewater treatment plant must be controlled. Aim to determine which control strategy delivers better performance with respect to plant operating cost; several control strategies for nitrogen removal are proposed and evaluated in the Wastewater Treatment Process Simulator which developed based on Benchmark simulation model. In the study, constant manipulated variables and various PI control strategies are tested and compared with model predictive control.