Sludge retention time = lbs of SS in the system/lbs of SS leaving systemoraeration tank MLSS x volume of aeration tank and secondary clarifier (as million gallons) x 8.34 / WAS TSS conc x WAS flow x...
retention time = volume of object/flow rate through object
so, in our example:
retention time = 500 (gpm) / 2000 (gpm / hour flow rate) = 0.25 hours (which is 15 minutes).
so a given sample of water...