Activated-Sludge Oxygen and Blower Air Demand
The oxygen the aeration system must supply and the blower air to deliver it: O2 = factor x BOD_removed + 4.6 x NH3_nitrified, air_scfm = O2 / (0.075 x 0.232 x SOTE x 1440). Nitrification adds 4.6 lb O2 per lb ammonia-N (easy to forget); diffused-aeration SOTE is only ~10-35%, so the air demand dwarfs the oxygen pounds. The largest energy cost at a plant.
Formula and source
O2_demand = oxygen_factor x BOD_removed + 4.6 x NH3_nitrified; air_scfm = O2_demand / (0.075 x 0.232 x (SOTE/100) x 1440).
Activated-sludge oxygen and air demand (WEF aeration design), by name.
Audience
This tile is built for trades and the adjacent professions in the Water and Wastewater Operations group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
Related tools
Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.