Arapid-mixing basin is to be designed for a water coagulation plant, and the design flow for the basin is 15,140m3/d. the basin is to be square with a depth equal to 1.25 times the width. the velocity gradient is to be 900 s-1 (at 10 °c), and the detention time is 30s. determine: a) the basin dimensions. b) the input power required. c) the impeller speed if a vane-disc impeller with six flat blades is employed and the tank is baffled. the impeller is to be 50% of the basin width.