The problem is that the ...
Published by Colin Greenhalgh
The problem is that the settleability test shows the settlement of:
- 180 mg/l for aerator 1,
- 220 mg/l for aerator 2,
- but the settlement for aerator 3 is increased and is 350 mg/l after 30 mins of the settleability test.
How to reduce the settlement in aerator 3?
For a start I had to look up the Mohlman Index (Cheers Gerd) and found out Molman was the chap who devised the Sludge Volume Index. Who knew? Well not me until now. (Is this another Centigrade vs Celcius thing?)
I suspect the figures you are quoting - 180/220/350 are the Sludge Volume Index (SVI) or hopefully Stirred Sludge Volume Index (SSVI) and better still SSVI at 3.5g/l which allows for comparison of sludges at differing MLSS. The SVI and SSVI use the unit ml/g to show how much volume the sludge occupies after settlement. The higher the number, the poorer the sludge settles.
If we take the SSVI in reactor 3 it just doesn't sound good at 350, but the important part is are you losing solids from your clarifiers? You do have clarifiers?
If you are not losing solids then what is your real concern.
A cheap USB linked microscope (£50) linked to a PC - from Aldi or many other sources - would just about have sufficient magniofication to allow you to post some pictures of the flocc. Now that would bring you some responses.
I understand recent develoments using the NERADA process obviate such settlement base concerns. But hey, like we say oop North, we'll manage with what we've got.
Presumably your plant worked fine at some point.
CG