• Blog
  • Wastewater Testing
  • Bioaugmentation Applications
  • Useful Information
  • About Us
BIOLOGICAL WASTE TREATMENT EXPERT
Contact Us

Diluted SV30 test - for systems with very high MLSS

2/18/2020

 
Picture
Photo of SV30 test from http://web.deu.edu.tr/
When you have MLSS above 5,000 mg/L, SV30 tests often have solids with a very narrow band of supernatant. This can make it difficult to diagnose problems with pin floc, settling velocity, and compaction. If you see the water phase of less than 20% of the settleometer, the diluted SV30 test may prove useful. Here is how to run a diluted SV30:
  • Fill your settleometer with 25 - 50% MLSS taken from the aeration basin. Make sure you mix the sample first to ensure you have solids all suspended.
  • Use effluent or tap water to fill the settleometer. Again mix the MLSS/Water blend to suspend the solids.
  • Start 30 minute timer. Note sludge level at time 5, 10, 15, 20, 25, & 30. Adjust dilution to have SV30 settled solids reading between 150 - 300 ml on the settleometer. After settling, note floating solids and pin-floc in the supernatant. You should also let the solids continue to compact for 2 - 4 hours. Evaluating the compacting solids gives information about how concentrated the RAS solids will become in the secondary clarifier.
  • For reporting purposes and SVI calculations, remember to multiply by your dilution factor.

Frederik Wynants
2/21/2020 12:04:52 am

When i run al diluted SV30 i get straggler flocs in the supernatant. The more i dillute the more stragglers. What does that mean ? Initial MLSS concentration is around 3700 mg/L. By straggler flocs i mean relative big but fluffy, light macroflocs.

Grace Wright
5/10/2021 10:44:34 am

The short answer is, It depends.

What is your MLSS?
What is your SV30 without dilution?

If you are not over 5000 mg/L and 750-800 on your MLSS / SV30
it probably does not mean much.

Have you run a side by side?
One not diluted and the other diluted?
If they were not pretty close after adjusting for the dilution factor there isn't much point in doing them.

Generally young sludge settles pretty quick leaving straggler flock behind. Sludge should be tan to brown. Increase augmentation (waste less).

Generally old sludge settles very fast, leaves a lot of particles behind, is very dark to black in color and the supernatant is dark and ashy. Decrease augmentation (waste more).

Are you using a real settlometer or a cylinder?
We have seen higher numbers on the same sample when using the tall form over a using a true settlometer.

Frederik Wynants
5/13/2021 10:23:22 am

Thank You for you answer Grace. I use a 1 liter glass cylinder. I am aware of the fact that the type of recipient can influence the SV30 value. But what fascinates me are the effluent suspended solids in the supernatant. Obviously the initial concentration of the MLSS has to do with it. Probably some kind of flocculation phenonemon i think.


Comments are closed.

    Author

    Erik Rumbaugh has been involved in biological waste treatment for over 20 years. He has worked with industrial and municipal wastewater  facilities to ensure optimal performance of their treatment systems. He is a founder of Aster Bio (www.asterbio.com) specializing in biological waste treatment.

    View my profile on LinkedIn

    RSS Feed

    Click to set custom HTML

    Archives

    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    June 2022
    May 2022
    March 2022
    February 2022
    January 2022
    November 2021
    October 2021
    September 2021
    August 2021
    June 2021
    April 2021
    March 2021
    February 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014

Proudly powered by Weebly
Photos used under Creative Commons from Picturepest, marcoverch, perzonseowebbyra, Picturepest, Picturepest, dsearls, dungodung, Massachusetts Office of Travel & Tourism, aqua.mech, vastateparksstaff, hile, Aaron Volkening, amishsteve, Neil DeMaster, mklwong88, KOMUnews, Picturepest, kaibara87