An impeller-powered flocculation basin is to be designed for a tertiary treatment plant having a flow of 25 MGD. The plant is to employ alum coagulation. and pertient data for the folcculation basin are as follows: detention time = 20 min, G = 35 /sec at 50F, GT = 10000 to 100000, width = 1.25 depth, length = 2width, no baffling, number of impellers = 2, blades per impeller = 6 pitched at 45 degreen angle, impeller diameter = 30% of width, KL = 70 and KT = 1.65
Determine the speed of the impellers in rpm