4aerobic digesters (water depth = 15 ft) received waste from an mbr treatment plant. given conditions: q = 0.5 m. g.d., bod = 180 mg/l , soluble bod = 100 mg/l, t. s.s. = 200 mg/l, v. s.s. = 160 mg/l, mlss = 7000 mg/l, srt= 28 days, y= 0.8 and kd=0.04 (d-1 ). the target effluent soluble bod is zero. calculate the aeration basin volume, waste sludge, and volume of each aerobic digester required to meet class b requirements.

Water at 70°f and streams enter the mixing chamber at the same mass flow rate, determine the temperature and the quality of the exiting stream. 0 psia is heated in a chamber by mixing it with saturated water vapor at 20 psia. if both streams enters the mixing chamber at the same mass flow rate, determine the temperature and the quality of the existing system.

Aquick transition of the operating speed of a shaft from its critical speed will whirl amplitude. (a) increase (b) limit (c) not affect (d) zero

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]