Foaming in activated sludge ...
Published by Huie Meili
Foaming in activated sludge process is a common operational problem in many wastewater treatment plants. The foam can occur in aeration tank, secondary clarifier, as well as in anaerobic digester. Foam in WWTP is normally sticky, viscous and brown in color. It floats and accumulates on top of the tanks, and can take up a large fraction of solids inventory and reactor volume, thus decreasing the effluent quality and control of sludge retention time (SRT).
In your case, Low possibility of anoxic conditions, because the Imhoff is more anaerobic then anoxic reactor and also this kind of foam i observed at the effluent from covered circular classifiers, same with H2S smell ->probably in these settler the sludge take out occurred in rare occasions and turned into a quasi A.D.
In your case, Low possibility of anoxic conditions, because the Imhoff is more anaerobic then anoxic reactor and also this kind of foam i observed at the effluent from covered circular classifiers, same with H2S smell ->probably in these settler the sludge take out occurred in rare occasions and turned into a quasi A.D.