WEF Discussions — Now on LinkedIn!

WEF is pleased to announce the creation of free LinkedIn groups associated with its technical discussion forum topics. Through these LinkedIn groups, members will be able to view and participate in discussions, as well as communicate with one another via direct messages. Share your experiences and knowledge, ask questions and respond to other discussions as frequently as you like!

You must have a LinkedIn profile to join a LinkedIn group; you can create your profile here. If you already have a LinkedIn profile, all you need to do is submit a request to join one or all of the following groups:

Water Environment Federation (Main) | Biosolids | Collection Systems | Nutrients | Stormwater 
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floating sludge problem
Posted: Thursday, April 22, 2010 10:19 PM
Joined: 4/22/2010
Posts: 2



We have air extended plant, suddenly begin to appear a floating sludge at aeration and settlement tanks. The appearance of this sludge look like a clod of earth with a gelatinous consistency, and appear in a regular hour.

The oxygen in aeration tanks is ok.


Any clue about what could cause this.



Posted: Saturday, April 24, 2010 6:42 PM

Best guess based on limited info is denitrified sludge. Check your air levels with another probe. If you can (depending on effluent requirements), increase the recirculation from your clarifiers. Another thing I found helpful was to reduce/stop the mixed liqour recirc flow to the anoxic selector. You may want to check your current flows vs. design flows too see if low flows are causing a long retention time in your basins. Good luck!