If 50% of BOD is degraded in 3 days how much time (in days) is need to degrade 55% ?

Poorly treated municipal wastewater is continuously discharged directly into a lake. The discharge from the wastewater plant into the lake occurs at a flow of Qd = 1 m3/hr. The concentration of phosphate (PO43, M = 95 g/mol) in the discharge flow (Cxd) that is decaying with first-order kinetics is 100 mg/L. The lake is a well-mixed water body of 100 m3. (Phosphate is naturally uptaken by algae with a first- order decay rate constant equal to 0.20/day.) The concentration of phosphate in the incoming river (Cx,r) is 10 mg P/L. The incoming river flow rate is Q, = 10 m3/hr. %3D a) Which of the following equations represent the correct mass balance equation? O va = CxQr - CxdQd -QoutCxvout" kCx,outV %3D O 0 = Cx,Qr + CxdQd -QoutCxvout" kCx,outV X,r O 0 = CxQr + CxdQd -QoutCxvout- kV O 0 = Cx,dQr + Cx,,Qd -QoutCxout- kCxoutV

It is the decrease in value of physical properties with the passage of time and use. depletion deletion decapitation depreciation

One of the steps in the commercial production of candy is the mixing of sugar and water to form a slurry with a density of 1200 kg/m³ and a viscosity of 5 x 10-3 kg/m-s at 20 degrees Celsius. The slurry then overflows from the mixer to a trough that is connected to a 6-inch smooth pipe leading to a receiving vessel that is 4 m lower than the trough. This 15-m long pipe contains two short 90-degree bends (Kw = 1.2) and an open gate valve (Kw = 0.05). How fast is the slurry flowing through the pipe (in m/s) and at what capacity (in m³/h)? Illustrate the system and indicate the reference points on which the balances are based.