Process Design: Activated Sludge with Turbine Aeration

Flow, Q MLD (Given)Influent BOD5, mg/L (Given)Hydraulic Detention Time, hrs (Choose)Aeration Tank Volume, m3 (Calculate)No. of Tanks ProvidedVolume/ Tank, m3Surface Area/Tank, m2Length/Tank, mWidth/Tank, mDepth, mEffluent BOD5, mg/L Ks (mg/L)qm(/d)q (/d)YT Kd (/d) mu (/d)BSRT, daysX, mg/L (Calculate)Del X, kg/d (Calculate)Influent Inert solids concentration, Co mg/L Inert solids conc. in aeration tank, C mg/l Solids conc. to settling tank, (C+X), mg/L Solids conc. in thickened sludge,(Xr+Cr), mg/LInert solids conc. In thickened sludge, Cr, mg/LBiomass conc. In thickened sludge, Xr, mg/LQw, MLDRDel (C+X), kg/dSolids Input to the Clarifier, (1+R)Q.(C+X), Kg/hr(RQ+Qw) (MLD)Solids output from the Clarifier, (RQ+Qw).(Cr+Xr), Kg/hrunderflow velocity, u m/hrSurface Area Provided A1, m2Limiting Solid Flux (kg/m2/hr)Minimum Surface Area Required A2, m2Actual Solid Flux in the clarifier, Q(1+R).(C+X)/A1 = (RQ+Qw).(Cr+Xr)/A1, kg/m2/hrNo. of Settling Tanks ProvidedArea per settling tank, m2 Diameter (Circular Tank Provided), mDepth, m (Given)Detention Time, Hours

Process Design: Provision of Turbine Aerators

a

Oxygen Requirement per tank, Kg O2/d

SOT, Kg O2/ KW/hr

b

qC, mg/L

Power requirement per tank for aeration, KW

Power requirement/tank for mixing, KWPower provided per tank, KWNumber of aerators per tankPower per aerator, KWElectricity Tariff, Rs/KW-hrTotal aeration Cost, Rs./d

Sewage Temperature, oC

Cs (20 oC), mg/L

Cs (30 oC), mg/L

AOT, Kg O2/KW/hr

Power Input for mixing, W/m3

Aeration Cost per unit volume of wastewater, Rs./m3

Process Design: Activated Sludge with Turbine AerationSolids V Gravity Flux u, m/hr Underflow Flux

mg/L m/hr kg/m2/hr Kg/m2/hr2000 3.60 7.196 0.100 0.200

50.00 2500 1.86 4.655 0.100 0.250350.00 3000 1.09 3.261 0.100 0.300

6.00 3500 0.69 2.414 0.100 0.35012500.00 4500 0.33 1.478 0.100 0.450

5.00 5000 0.24 1.203 0.100 0.5002500.00 6000 0.14 0.843 0.100 0.600833.33 6500 0.11 0.721 0.100 0.65055.00 8000 0.06 0.481 0.100 0.80015.15 10000 0.03 0.311 0.100 1.0003.00 12000 0.02 0.218 0.100 1.2004.0025.004.000.550.500.05

0.2264.43

2508.507082.1950.00

885.503394.0012806

334194650.7480.340

9582.19947717.769477

0.10074001.2873981.28

51480.03

43.412.005.30

Process Design: Provision of Turbine Aerators

31791.5000.800

0 2000 4000 6000 8000 10000 12000 140000.000.501.001.502.002.503.003.504.00

f(x) = 20000000000 x^-2.9521

Interfacial Settling Velocity

Solids Conc. (C+X) mg/L

Inte

rfa

cia

l V

elo

cit

y (

v),

m/h

0 2000 4000 6000 8000 10000 12000 140000.000

0.500

1.000

1.500

2.000

2.500

3.000

Limiting Solid Flux

Solids Concentration (C + X), mg/L

To

tal

So

lid

s F

lux

, k

g/m

2/h

r

Limiting Flux

0.900

30.00

9.10

7.50

1.021.00

0.924143.29

2050.00165335

6.50128700

2.57

Total Flux

kg/m2/hr7.3964.9053.5612.7641.9281.7031.4431.3711.2811.3111.418

0 2000 4000 6000 8000 10000 12000 140000.000.501.001.502.002.503.003.504.00

f(x) = 20000000000 x^-2.9521

Interfacial Settling Velocity

Solids Conc. (C+X) mg/L

Inte

rfa

cia

l V

elo

cit

y (

v),

m/h

0 2000 4000 6000 8000 10000 12000 140000.000

0.500

1.000

1.500

2.000

2.500

3.000

Limiting Solid Flux

Solids Concentration (C + X), mg/L

To

tal

So

lid

s F

lux

, k

g/m

2/h

r