Your firm has been asked to design the third-stage plug-flow…
Your firm has been asked to design the third-stage plug-flow, nitrification-denitrification reactor for one of your long-term municipal clients. Pertinent design data are as follows: Design flow: 6.25 MGD Temperature 20 °C MLVSS/MLSS: 0.75 2nd stage nitrate (NO3–N) concentration: 30 mg/L Effluent nitrate (NO3–N) concentration: 1.0 mg/L Effluent TSS concentration: 3 mg/L Denitrification cell yield coefficient (Y): 0.85 mg MLVSS/ mg NO3—N removed Endogenous decay constant (ke): 0.04 day-1 Peak nitrate removal rate (): 0.27 mg NO3–N removed/mg MLVSSday Half-saturation constant for denitrification (KD): 0.15 mg NO3–N/L MLSS concentration: 2,800 mg/L Methanol requirement: 3.0 lb methanol/lb nitrate removed Methanol specific weight: 6.60 lb/ft3 Determine the following: (5 pts) “Design” MCRT for denitrification (Days) (5 pts) If the design MCRT for denitrification is calculated to be 5.39 days, determine nitrate removal rate (q)(unit: mg NO3—N removed/ mg MLVSS