An Intelligent Decision Support System for Wastewater Treatment Plant Management

The paper describes the design of a finite state automaton which forms the kernel of an Intelligent Decision Support System that has been implemented and integrated into the existing supervisory control and data acquisition system at a medium scale municipal Wastewater Treatment Plant. The system provides real-time support and advice to the operators and the manager of the plant for a wide range of operating situations by following the policy that the plant manager follows to maintain normal operation. The system has proved effective in managing the complex process in all but extreme environmental conditions and performs equally well and more consistently than the human operator. The paper describes the emulated knowledge-based automaton designed in the MATLAB/ Simulink environment. NOMENCLATURE WWTP = Wastewater Treatment Plant ASP = Activated Sludge Process SCADA = Supervisory Control and Data Acquisition System IDSS = Intelligent Decision Support System BOD = Biological Oxygen Demand COD = Chemical Oxygen Demand SS = Total Suspended Solids N = Total Nitrogen concentration N-NH4 = Ammonium Nitrogen concentration N NO3 = Nitrate Nitrogen concentration P = Phosphorus concentration MLSS= Mixed Liquor Suspended Solids RASS= Suspended Solids in the Recycled Sludge ΔO2 = Incremental change in the Oxygen set-point ΔWSR = Incremental change in Waste Sludge Flow Rate ΔAnoxic = Incremental change in the Anoxic Bioreactor Aeration Rate Q = influent flow rate