LOWER SLUDGE VOLUME INDEX

[appy1]

I am treating industrial effluent by conventional treatment system Anaerobic-anoxic-oxic-clarifier. In the final aeration stage, SVI (a measure of sludge settleabiliy) remians very low about 30-40 ml/gm. can anyone explaine why it is so low. before implementing anoxic stage in anerobic -aerobic process there was floating sludge problem, but anoxic stage helped get ride of that!

 

[bimr]

There are a number of things that can cause poor settling.

1. Organic overload.
2. Low DO.
3. Overmixing

1. YOu need to microscopic examination the sludge to determine the type of microorganisms present.

2. Check the DO.

3. Check the F/M ratio.

Floating sludge indicates denitrification that is typicaly caused by holding sludge in the clarifier for too long a period.

 

[appy1]

bmir, udid not get the problem

my concern is lower SVI not poor settling ?

 

[bimr]

Lets try again.

The SVI value that is characteristic of a good settling sludge varies with the characteristics and concentration of the mixed liquor solids, so that observed values are not comparable to other reported activated sludge systems.

If the MCRT is kept within the range of 3 to 15 days, the SVI is usually optimal. Longer MCRT's may act to decrease the compactibility of the sludge, but long MCRT's are often required, particularly in industrial wastewater treatment applications. In such applications, it is important to properly size the clarifier for the settling characteristics of the sludge.