PROCESS CONTROL WITH A FLOWMETER PART 4

In this last part we will look at how to account for sludge blankets that or 2 feet deep and more.

In this example wwe will use the old Lynn Marshall average between MLSS and RAS

But Jim! We don't have any MLSS or RAS data!

Fear not, nimrod, I'll show you how

Lets use the 70' diameter clarifier from above

The blanket depth is 2 ft

The blanket volume is 35 x 35 x 3.14 x 2 x 7.48 = 57,500 gallons

to get the MLSS equivalent volume we take the average of the RAS solids and the MLSS solids

From the above lessons, the RAS equivalent is 3 and the MLSS equivalent is 1.  So

MLSS equivalent = 3+1/2 or 4/2=2

MLSS equiivalent gallons = 57,500 x 2 = 115,000 gallons

Total MLSS = 1,000,000 + 115,000 = 1, 115,000

for an 8 day MCRT  1,115,000/8 139,375 gallons as MLSS or 46,500 gallons as RAS

Pretty neat, huh?