Sedimentation tanks in a water treatment plant are required to be designed to achieve a minimum hydraulic detention time of 3.0 hours and a maximum overflow rate (surface loading rate) of 750. gal/d/ft2. For a water production rate of 500,000. gal/d, determine the dimensions of rectangular sedimentation tanks required (length, width, depth). Round dimensions to the nearest ft. There should be a minimum of 2 tanks in parallel for reliability.

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2