A compound control method for coagulant dosing in Waterworks

Changes of raw water quality and water flow has obvious influence on the coagulation process of waterworks. However, most waterworks still adopt manual control method based on fixed proportion of water flow. The coagulant dosage can not be adjusted in time according to the change of raw water quality and water flow, so that the coagulant dosage can not be adjusted in time. It is easy to cause large fluctuation of turbidity of effluent from sedimentation tank with large lag. In order to improve the self-adaptive ability of coagulation process and stabilize the turbidity of effluent from sedimentation tank, a composite control method of coagulant automatic dosing based on RBF neural network (RBFNN) and PI control is studied in this paper. RBFNN provides timely feed-forward control information for coagulant automatic dosing according to raw water quality. PI control is used for feedback control of coagulant automatic dosing. The results show that, compared with manual control, the proposed compound control has better adaptability to the changes of raw water quality and water flow, and the turbidity of the effluent of sedimentation tank is more stable.