Bayesian Optimization-Enhanced Reinforcement learning for Self-adaptive and multi-objective control of wastewater treatment

Controllers of wastewater treatment plants (WWTPs) often struggle to maintain optimal performance due to dynamic influent characteristics and the need to balance multiple operational objectives. In this study, Reinforcement Learning (RL) algorithms across different activated sludge process configurations was tested, and a novel approach that integrates RL with Bayesian Optimization (BO) to enhance the control of critical operational parameters in activated sludge processes was developed. This study extended the application of advanced machine learning techniques to complex WWTP control problems, moving beyond simplified benchmarks. The integration of BO with RL avoided sub-optimal performance and accelerated convergence to optimal control policies in controlling the A2O process, resulting in a significant 46% reduction in operational costs and a 12% decrease in energy consumption while maintaining compliance with effluent discharge standards. This approach offers a practical pathway for WWTPs to enhance treatment efficiency, reduce operational costs, and contribute to sustainable wastewater management practices.