High sludge index and recirculation problem

Your sludge index is just above 200 mL/g, which indicates settling problems (and maybe a bulking issue). You are also seeing this poor settling in your recirculation rate.

I have a few questions:

- Has your SVI varied by more than 40 ml/g since your last analysis?

- What is the separation of sludge/water in your V30 test and sedimentation tank like?

- Do you see any gas bubbles in your sludge?

- Are you loosing SS?

To answer your questions:

- No, three days ago it was at 186

- For my test V30 test, settling is done adequately without degassing, but I see chocolate-coloured floating matter on the surface of the clarifier

- Also there are brown bubbles on the surface of my aeration tank but that’s all—when I collect my sludge samples, I don’t see any bubbles.

- SS losses? Not sure what you mean.