An intelligent system for precise management of coagulants in sludge conditioning: Inspired by the exploratory behavior in primates using senses

Coagulation conditioning is a key step for sludge dewatering, while the control of optimal coagulant dosing is still a challenge. This study proposes an intelligent system for the precise management of coagulants (IIS PMC ) in sludge conditioning. This system was assembled using an electrical impedance spectroscopy (EIS)-based sensor and a decision-making model to conduct the self-perception, decision-making, execution, and dosage optimization in sludge conditioning through a feedback-driven exploratory trial process, conceptually inspired by structured exploration behavior observed in primates. Using the optimal dosage obtained by the traditional manual jar test as the reference, the accuracy and repeatability of the IIS PMC were investigated. The robustness under different perturbed conditions, reliability, and generalizability of the IIS PMC were further assessed. Moreover, the long-term operational capability and the feasibility of the application in the scaled-up conditioning were also discussed. The results showed that the intelligent system achieved statistical median accuracy and repeatability of approximately 5%, good reliability with a 5 g/kg resolution (R 2 > 0.94 in validation tests) in determining the optimal coagulant dosage, and strong robustness under sludge conductivity and concentration perturbed conditions. In addition, the performance of the IIS PMC was validated across different sludge sources, including activated sludge, dredged sediment, and algal sludge, as well as different coagulants, exhibiting solid generalizability. The system also demonstrated stable continuous operation over 40 batches, which is equivalent to the number of continuous operation batches of a small-sized treatment plant over approximately half a month. Furthermore, even after scaling up the conditioning tank, the IIS PMC maintained stable performance. These findings highlight the potential of the IIS PMC for practical applications in sludge conditioning.