1. A municipal WW activated sludge facility has the following characteristics: Flow = 7.2 million liters per day Influent BOD5 = 200 mg/L Aeration basin volume = 3,000 m3 Two circular clarifiers (each with diameter = 20 m and depth = 4.0 m) Return activated sludge flow rate = 3.5 million L/day per clarifier MLVSS concentration = 3,500 mg/L Effluent VSS is negligible Sludge VSS concentration = 6,800 mg/L Determine the daily volume of sludge (liters per day) that must be removed to maintain a solids residence time of 5 days.