Given an aerated lagoon with a depth of 9.4 meters receives wastes containing 15 mg/L of biologically degradable material (Q = 8640 m3/d). At steady state conditions, the first order reaction rate constant is 0.08 day-1 and the effluent concentration cannot exceed 11 mg/L. If you assume the lagoon is completely mixed and evaporation/seepage are negligible, what is the surface areas of the lagoon in acres?

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.