A WWTP utilizing the complete-mix modification of the activa…

A WWTP utilizing the complete-mix modification of the activated sludge process is located at 1,000 FMSL. The oxygen demand for the facility is 9,625 lb O2/day during the summer months when the maximum wastewater temperature is 84.2 ° Four mechanical aeration devices are to be used and the aerator manufacturer has determined the oxygen transfer to be 2.3 lb O2/hp-hr. Determine the theoretical aerator power (hp) per aerator if the operating DO is 1.8 mg/L. Assume α and β values of 0.75 and 0.95, respectively.   (5 pts) Determine saturation dissolved oxygen concentration of the wastewater (Cw) (unit: mg/L) (5 pts) If Cw is 7.12 mg/L, determine rate of oxygen mass transferred (N) (unit: lb O2/hp-hr) (5 pts) If the rate of oxygen mass transferred is 1.196 lb O2/hp-hr, determine aerator horsepower required (each)? (unit: hp)

A local municipality has contracted with your firm to design…

A local municipality has contracted with your firm to design an induced-draft, counter-current, ammonia stripping tower at their water reclamation facility that has a permitted capacity of 5.0 MGD. Pertinent design data as follows: Average air and water temperature: 20 °C Wastewater pH: 11.0 Local atmospheric pressure: 725 mmHg Design hydraulic loading: 2.5 gpm/ft2 Design/theoretical air flow: 1.70 From the table, the partial pressure of ammonia at 20 °C is 0.03 mmHg and the ammonia concentration in the wastewater at 20 °C is 50×10-6 gNH3/gH2O.   (5 pts) Determine the equilibrium mass of ammonia in the air (Y2) (5 pts) Determine the air to water ratio (lb Air/lb H2O). (5 pts) If the G/L=2.0613 lb Air/lb H2O, determine the theoretical air required (Gtheor) (unit: lb Air/ft2·hr). Hint: determine the mass flow rate of water (L) first. (5 pts) If the theoretical air required (Gtheor) is 2,580 lb Air/ft2·hr, determine the “design” air required (lb Air/ft2·hr).  (5 pts) If the design air flow required is determined to be 750 cfm/ft2, what is the design air flow required (Air/Gallon)? (unit: ft3/gallon)