1.An operator at a wastewater treatment plant decided to increase the SRT from 5 days to 10 days. How will this change affect: a) the oxygen requirement b) MLVSS in the aeration tank. c) the effluent BOD or COD. d) the sludge generation (please explain your answer using the kinetic equations for activated sludge process)
2.An airplane with a Clark Y airfoil cross-section weighs 3500 lbs. The chord length is 6ft and the wingspan is 36 ft. Determine the:
a) Minimum speed and power to take off, if the angle of attack is 12.4 degrees.
b) Power to cruise at 150 mph at an altitude of 15,000 ft.
c) % increase in power if the plane is cruising 150 mph at 10,000 ft. d) Stall speed at landing