Different sludge growth



We have at our treatment three Uplift Anaerobic Slib Beds (UASB).

Currently we are experiencing problems with one of the reactors.

The sludge in this reactor does not form a granular structure as it normaly does. Insteed it forms loose flakes that are easily washed out, hence we are losing sludge at a fast rate.

It does however produce biogas at a comparable rate than the other reactors. The fatty acids are also under control, as well as pH and temperature.

The reactor was only startup about a year ago and received somewhat similar sludge than the second reactor. For a period this evolved in the same way but in the last couple of weeks this has changed dramaticaly.

Does anyone have any idea why the sludge can be so different if al the other parameters are the more or less the same?