Given that a wastewater treatment plant (wwtp) discharges 110 mgd treated effluent containing 20 mg/l bod and 2 mg/l dissolved oxygen (do) into a river with flow rate of 15 m3 /s, 5 ppm do, 6 ppm bod and 50 mg/l as caco3, determine the bod and do (both in ppm) just downstream from the sewage outfall.

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater