Volumetric loading compares the BOD load with basin volume. Conventional activated sludge is often 20 to 40 lb BOD/1,000 ft³/d; extended aeration 10 to 25.
Aeration Basin Organic Loading
Formula
Loading, lb BOD/d per 1,000 ft³ = (Q, MGD x BOD x 8.34) / (Volume, MG x 133,680.6 / 1,000)
Inputs used
- Flow to aeration (MGD)
- Aeration influent BOD (mg/L)
- Aeration volume (MG)
Worked example (White River WRRF, fictional)
- BOD load = 8.0 x 150 x 8.34 = 10,008 lb/d
- Volume = 3.6 x 133,680.6 / 1,000 = 481.3 thousand ft³
- Loading = 10,008 / 481.3 = 20.8
Tips
- Use aeration influent BOD.
- Compare with design and with F/M.
Results are estimates for operator use. Check units and inputs, and confirm decisions with plant data and procedures.