Using the assumptions given in Example 8-4 (page 495), the rule-of-thumb values for growth constants, and the further assumption that the influent BOD_5was reduced by 32.0 percent in the primary tank, estimate the liquid volume of a completely mixed activated sludge aeration tank required to treat the wastewater in Problem 8-1 (above). Assume an MLVSS of 2,000 mg/L.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.