A stabilization pond is to be designed for a community with…
A stabilization pond is to be designed for a community with a population of 3,000 people, to provide secondary treatment. Primary treatment of the wastewater is to be provided. Pertinent design data for the facility are as follows. Solve each problem to determine the design parameters. Raw wastewater flow rate: 90 gpcd Influent BOD5: 200 mg/L Primary clarifier BOD5 removal: 30% BOD5/Ultimate BOD: 70% of stabilization ponds in parallel: 2 Pond length to width ratio = 3:1 Pond depth: 5 feet Winter operating temperature: 45 °F (=5.56 °C) Algal toxicity factor (f) = 1 Sulfate concentration is less that 500 mg/L; so f´=1 Temperature coefficient (θ)= 1.07 (4 pts) Determine raw wastewater flow rate (Qww, unit: gpd). (Hint: unit is gpd, not MGD) (4 pts) Calculate primary clarifier effluent BOD5 (mg/L). (4 pts) Ultimate BOD (L0, unit: mg/L). (4 pts) Determine the total stabilization pond volume required (V, unit: ft3) (Hint: C=0.0047, show the total volume, not a single pond) (4 pts) Determine the total stabilization pond surface area (A) required (acres). (Hint: 1 acre = 43,560 ft2, show the total surface, not a single pond) (4 pts) Determine width (ft) of each pond in 5 ft increments. (Hint: each pond has identical width) (4 pts) If stabilization pond width:depth (W:D) ratio is suggested to be 48:1, determine the design depth (ft).