WEF Discussion Forums : Operation and Maintenance : Why effluent clears-up after interruption of aeration?


- release of extracellular polymers by stressed bugs,

- die-off of free swimmers.


Any other suggestions?

Does anybody else have a similar experience?


Fri, 23 Sep 2011 20:35:08 GMT





In addition to the SVI, microscopic examination of the activated sludge under phase contrast @ 200 X (or with a regular microscope with the condensor lowered to enhance contrast) the floc was dense and clotty.  You could tell that, because as you focus up and down...the floc was dense...no wastes or oxygen get's to the center of the floc.


If these are consistent with your experience, you might want to consider slowly lowering the sludge age/MLSS to promote growth of the better activated sludge.  Since you have to nitrify...be careful.  I'd confirm that the F:M was very low...SVI is low...pounds BOD loading to the aeration basin is low.


Please let us know whatever you find!!!!!





Sun, 09 Oct 2011 00:34:51 GMT