I want to use the sludge or granules from a UASB reactor to start few more new UASB reactors (both lab scale). Before using it I would like to measure the above mentioned parameters. Can anyone suggest me some standard procedures for the analysis of the same.
Thank you
Please follow the paper. This might be helpful for you!
Conference Paper ASSESSMENT OF EFFICIENCY OF AERATION TANK OPERATION IN THE E...
I also agree with the opinion of professor Looddrecht. The methods are same between aerobic systems and the anaeribic systems. And I think you'd better check the national standard methods in your country.
Best regards!
I AGRREE. Methods are exactly the same as for aerobic systems.
MLSS, MLVSS: St. Methods 2540 Α, Β, C, D (22nd Ed.2012)
SLUDGE: St. Methods 2710 C, D (22nd Ed.2012)
agree check with regular textbooks eg. metcalf and eddy wastewtaer engineering
Hi Dr Arun
you can use this relations:
1-The total weight of MLSS within an anaerobic tank can be calculated by multiplying the concentration of MLSS (mg/L) in the anaerobic tank by the tank volume (L).
2-Mixed liquor volatile suspended solids =
The portion of the MLSS that is actually eating the incoming food is referred to as the Mixed Liquor Volatile Suspended Solids (MLVSS). The volatile solids concentration in a sample of mixed liquor will consist mostly of microorganisms and organic matter. As a result, the volatile solids concentration of mixed liquor is approximately equal to the amount of microorganisms in the water and can be used to determine whether there are enough microorganisms present to digest the sludge.
3-Sludge Volume Index (SVI) is used to describe the settling characteristics of sludge in the aeration tank in Activated Sludge Process. It is a process control parameter to determine the recycle rate of sludge. It was introduced by Mohlman in 1934, and has become the standard measure of the physical characteristics of activated sludge processes. It is defined as 'the volume (in ml) occupied by 1 gram of activated sludge after settling the aerated liquor for 30 minutes'.
SVI (ml/gm) = settled sludge volume/sample volume (ml/l) * 1000 (mg/g)/ suspended solid concentration (m/l)
good luck
Randa Osman
you can find full data about SVI in link below
http://www.tpomag.com/editorial/2010/03/what-the-heck-is-svi
Dr Arun
your are welcome at any time, hope everything is going well with you.
Arun,
When you want to start a new UASB taking biomass from an old UASB, you should be concerned with the concentration of total solids and volatile solids. These values may not be termed as MLSS and MLVSS because the biomass is contained in UASB blanket and not completely mixed with the supernatant in UASB. However, the analytical methods remain the same. Best thing you can do is to take a required volume of biomass from parent UASB, mix it properly, and then determine so called MLSS and MLVSS. If you want to determine total solids and volatile solids in a UASB in working condition, you may need to draw equal volumes of sludge samples from various points along the height of the balnket, mix them, and then analyse.
Dear Mr. Arun,
MLSS i.e. Mixed liquor Suspended solids. Mixed Liquor means the Effluent plus the bio culture that we add. suspended solids is what ever is suspended into it. If we do any primary Treatment with the waste water before letting it to the biological treatment, the TSS will not be removed 100%. Thus, for understanding purpose, MLSS is bacically the left over TSS after comming to the biological treatment plus the bioculture that we add to the Effulent.
To determine MLSS, take a known quantity of sample and put it to hot air oven at a temperature of 110 dec C. The funda behind is very clear, Just evaporate the water content. what ever is left is the MLSS.
MLVSS is the volatile content in the waste water. Basically, the bio- culture that we add, the microbes are volatile. to determine MLVSS, follow the procedure for MLSS and put the left over MLSS to Muffel furnace at temp 550 deg C. The Biological species to the biological system will not survive and will get volatile. What ever evaporated here is MLVSS.
Thus For understanding purpose,
MLSS= Left over solids before Biological Treatment + MLVSS
MLVSS = Biological Species added for effluent Treatment.
I hope this helps you.
Same to the aerobic systems. See standard methods for the examination of water and wastewaters, APHA, 2012
Do MLSS of the sample by keeping the filtered sample (solid portion) in oven at 103-105'c till constant weight. . The MLSS sample is kept in furnace at 550'c for 30 minutes for determining MLVSS
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