A wastewater treatment plant discharges 2.0 m^3/s of effluent having an ultimate BOD of 40.0 mg/L into a stream flowing at 15.0 m^3/s. Just upstream from the discharge point, the stream has an ultimate BOD of 3.5 mg/L. The deoxygenation constant kd is estimated at 0.22/day. a. Assuming complete and instantaneous mixing, find the ultimate BOD of the mixture of wastewater and river just downstream from the outfall.
b. Assuming a constant cross sectional area for the stream equal to 55 m^2 , what ultimate BOD would you expect to find at a point 10,000 m downstream?

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Atmospheric air has a temperature (dry bulb) of 80° f and a wet bulb temperature of 60° f when the barometric pressure is 14.696 psia. determine the specific humidity, grains/lb dry air. a. 11.4 c. 55.8 d. 22.5 b. 44.1

Have a greater impact on maintenance productivity than any other support group. (clo5) a)-the top management b)-inventory and purchasing c)-sub-contracting d)-cmms