Dynamic Alpha Factor from COD for Aeration
We have added an option to the Alpha Factor calculator on the SSI Technology Portal to derive alpha as a function of COD loading in a diffused aeration tank. It is an experimental method, suggested by Jiang, Garrido-Baserba, Nolasco, Al-Omari, de Clippeleir, Murthy and Rosso in their paper accepted by Water Research on July 15, 2017 entitled, “Modelling Oxygen Transfer Using Dynamic Alpha Factors.”
They showed a negative correlation of alpha as a function of COD with an r-squared correlation of 0.7. Their experiments showed COD varying significantly throughout the day at (3) municipal plants along with alpha. The COD was highest from 8am to 5pm, by a factor of 1.5 to 2.0 as compared to the rest of the day. One plant had coarse bubble diffusers, one had fine bubble disc diffusers and the other had panel diffusers.
To try it, visit the alpha factor calculator on the SSI Technology Portal here.