Hi Arun, As people have ...
Published by Daniel Adeoye, Application Development Manager at Hach
Hi Arun,
As people have already stated in the comments, the foaming is normally caused by filamentous bacteria. There are conditions which create an ideal environment for the proliferation of these bacteria. Think of it like survival of the fittest, the filamentous bacteria are bigger than the other bacteria and will dominate in situations such as:
Low F/M ratios.
Low DO
Insufficient nutrients.
The black MLSS is normally a sign of septicity, once again low F/M, you will need to reduce sludge age and WAS more frequently.