Optimal Controllers for the Operation of Activated Sludge Treatment Systems

Abstract

Objective: Application of Optimal Control Theory to the activated sludge process in order to regulate the removal of the carbonaceous part of the organic matter.   Theoretical benchmark: Dynamic models of activated sludge processes are capable of enabling the development of innovative control systems. The Optimal Control Theory, aimed at optimizing the performance of dynamic systems, allows the establishment of control systems that enhance efficiency in adapting to changes in operating conditions, ensuring satisfactory process performance.   Method: The proposed control systems were established from the application of Optimal Control Theory, considering the use of the dynamic model of the activated sludge process presented by International Association on Water Pollution Research and Control. Computer simulations were used to assess the performance of the control systems proposed.   Results and conclusion: The proposed control systems were capable of curbing substantially the oscillations in the concentrations of biomass, of particulate matter produced by the degradation of biomass and those of the inert particulate substrate. The reductions in the oscillations of the slowly biodegradable part of the influent were relatively smaller. The controller was quite effective in leading the wastewater treatment system sooner to the new equilibrium conditions after the imposition of the disturbances in raw effluent.   Implications of research: Development of control systems for activated sludge processes to regulate the removal of the carbonaceous fraction from organic matter.   Originality/value: The establishment of optimal control systems for activated sludge processes can enable greater efficiency and operational capacity, especially in industrial facilities or densely populated urban settlements, where such wastewater treatment systems are most commonly used.