Orchestrating the continuous self-circulating granular sludge process: An intelligent platform for real-time adaptive...

The separate aeration self-circulating technology (Zier) is a novel process for continuous-flow aerobic granular sludge process. Although advantageous for granulation and treatment efficiency, its operational performance is constrained by strong interdependencies among its operational parameters. This study established an integrated framework to address this challenge through parameter modeling, simulation, and real-time control implementation. Predictive models for the upflow velocity, aeration rate, and oxygen transfer coefficient demonstrated high accuracy, enabling precise operational control. Multi-scenario simulations identified the optimal reactor geometry under laboratory-scale conditions, defined by a reaction column radius of 0.175-0.3 m and a height-to-radius ratio of 6-10, for efficient pollutant removal. The simulations also revealed that higher sludge settling velocities can enhance the ammonium removal rate by approximately 70% under high ammonium loading rate. The effectiveness of the framework was validated by implementing a real-time adaptive control strategy. Sludge bed integrity and dissolved oxygen levels were maintained throughout the operation. The system effectively maintained effluent NH₄⁺-N concentration below 5 mg/L despite inflow variations, while reducing aeration energy consumption by approximately 59%. Overall, this study provides a robust simulation tool and a foundational control strategy, paving the way for intelligent, automated, and highly efficient operation of the Zier process.