Dear researcher

I do not know these equatios are useful or not.

Total suspended solid=(2 to 2.4)*NTU   for secondary sedimentation effluent

Total suspended solid=(1.3 to 1.5)*NTU   for filter effluent

floculation dosage= 3.5  * radical of turbudity

Regards

I have used turbidity (NTU) or optical density (transmittance at 600 nm) as proxy parameters for flocculation efficiency in removing particles. I also use the UV absorbance at 254 nm/220 nm as proxy for DOC removal.

There are no general formulas that applies in converting these parameters to SS or DOC so one has to make a calibration in for each water type.

Higher the flocculation efficiency, higher will be the turbidity, lower be the transmittance.

Check the following paper, hope it will work.

Adrij, flocculation removes suspended particles thus turbidity decrease with efficient flocculation.

Henrik, I am talking before the sedimentation occurs, correct me if any.

I hope as the flocculation starts, it might require a minimum time so that the suspended particles get removed by gravity settling. Correct me if any.

I am thinking about after the settling that is caused by the particles coagulating to larger flocs. Just as you add the flocculant turbidity likely measures higher. We agree then. 

In my industrial experience, fine particles agglomerating into larger clumps of particles will, on average, scatter less light because they are larger, in a stirred system.  Light has more chance to directly pass through the clear areas that have arisen between the flocculated clumps.

Thanks a lot everyone for your inputs

@Adrij thanx for adding your answer

But just to correct Higher the flocculation efficiency lower will be the turbidity and thus Transmittance would be higher

I had done the experiments regarding the same and have found that Higher FE= Higher Transmittance and Lower Absorbance

Your question specifies "bacterial flocculants", not chemical based or plant based.  Is the bacterial flocculant is somewhat similar to the first 4 links below? Also your flocculation efficiency is based on what? Settling time, % removal, TSS, ??:

http://www.sciencedirect.com/science/article/pii/004313547590127X

http://www.sciencedirect.com/science/article/pii/S0043135402001732

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2140537/

http://www.bioline.org.br/pdf?st11077

http://ia800200.us.archive.org/30/items/proceedingsoflin25linn/proceedingsoflin25linn.pdf

You should be able to experiment and find a correlation between transmittance  as has been done in some of the links below and come up with a formula:

http://www.columbia.edu/~ps24/PDFs/Charge%20Effects%20in%20the%20Adsorption%20.%20.%20.%20Its%20Flocculation.pdf

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwjqsbjLh7TVAhXGNSYKHfYwDYYQFgguMAM&url=http%3A%2F%2Fwww.pjsir.org%2Feditorial-process%2Freviews%2F288_169_288_345_RP-Acryl-Text-Column-PJSIR.doc&usg=AFQjCNEb4mEfFnjRYYnPAWYPOCTO8xY1uA

https://www.hindawi.com/journals/jchem/2014/969720/

http://studylib.net/doc/8496473/of-polyacrylamide-as-a-flocculant

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66321998000400005

In the experiments flocculation efficiency is based on the % removal of the suspended particles measured through the reduction in the absorbance from high initial absorbance

In brief Bacterial flocculants are the extracellular polysaccharides secreted by bacteria in the production medium during their growth and metabolism

Thanks for the literature!

Hello Varsha, what you said is exactly correct. But if flocculation efficiency is characterised with settling time, then higher FE means lower settling time. Coming to my point, higher FE means there will be more agglomeration of suspended particles in the solution in 3D , mention you not 2D. If you consider a plane which divides  the beaker/ cubet into two equal halves, there will be movement of particles from both up & down the plane. Result will be a higher movement of particles in the solution. which will lead to temporal turbidity increase. If you measure immediately after adding flocculants, it will have lower transmittance. So, if time for settling is taken into consideration, then you are correct as you observed. 

Hope I didn't confuse you. Best of luck.