An extended aeration system, receiving de-gritted effluent is being designed for biological nitrogen removal at a minimal temperature of 15C. The system is to be designed on max day peak conditions, with a pre anoxic tank and internal recirculation of 4. For the following wastewater characteristics and design parameters, determine the following: 1. The aeration zone volume 2. The anoxic zone volume 3. The sludge production in kgTSS/d 4. The oxygen requirements 5. The recycle ratio, R, taking into consideration that the concentration of the RAS (MLSS) is 5000 mg/L 6. The HRT in the aeration tank at average flow conditions 7. The F/M ratio in gBOD/MLVSS.d at average flow conditions 8. The organic loading rate in gBOD/md at average flow conditions population Per capita average wastewater generation rate per capita TCOD load total COD load max day COD load per capita BOD load bCOD max day BOD load max day bCOD load SRT Design temp MLSS Degritted TSS per capita load Degritted TVSS per capita load nbVSS concentration Biokinetic coefficients at 20 C Coefficient units Ha K, Ko Y b f Ka 0 value Has b K, Ko gVSS/gVSS.d mg/L gV55/gd gVss/gVs5.d mg/L 6 8 0.45 0.12 0.15 0.2 1.07 1.04 L/cap.d g/cap.d Heterotrophic AOB 1 kg/d kg/d g/cap.d g/cap.d kg/d kg/d days "C g/m g/cap.d g/cap.d B/m 0.9 0.5 0.15 0,17 0.15 0.5 1.072 1.029 1 75000 113 8475 16441.5 60 98.4 8730 14317.2 20 15 3000 31.02 25.16 25