(15 points) A flocculator is designed to have three sequential basins, with decreasing mixing intensity in each basin. The first basin should have a mixing intensity of 60 s-',the second

should be 40 s', and the third should be 20 s'. The flocculator should be designed for a flowrate of 10 m³/min and a hydraulic retention time in each of the three basins of 20 minutes and an operating temperature of 15°C. Calculate the power that must be applied to each of the three impellers (in Watts) to achieve this design.

Fig: 1