Laserfiche WebLink
Technical Description ' <br /> E=mple: Calculate the F:M. <br /> Assumptions: <br /> Q =0.075 MGD <br /> Aeration tank volume, V= 0.050 MGD <br /> BODS = 125 mg/L <br /> MLVSS = 1600 mg/L <br /> F = Influent BODS <br /> = (BODS) (Q, MGD) (8.34 lb/gal) <br /> = (125) (0.075) (8.34) <br /> = 78,18 lbs/day <br /> M = Solids inventory in aeration tank <br /> = (MLVDD mg/L) (V, MGD) (8.34 lbs/gal) <br /> (1600) (0.50) (8.34) <br /> = 6672 lbs <br /> F:M = _78.18 BODS/day <br /> 6672 Ibs MLVSS <br /> 0.01 lb BOD./day/lb MLVSS <br /> Extended aeration detention sizing: <br /> Fxh = C <br /> H1 <br /> where <br /> F = 'Flow in gpd } <br /> h = Hours of detention <br /> H1 = Hours per day (24) <br /> C = Capacity of aeration chamber (to level of weir) <br /> Nitrification addition: <br /> Given: Maximum NH4 expected: 27.5 <br /> Desired: 27.5 to 26.5 = 94.5% removed <br /> so 26.5 x 4.2 Oz = 111.3 mg/L (lbs) of O2 is required for conversion. <br /> CLARIFIER SIZING <br /> Sedimentation is based upon detention capacity design. Since.the entire volume of mixed liquor in <br /> aeration standby (batch) is physically transferred:into the clarifier, settling time may be adjusted to <br /> allow even the smallest particle to settle. <br /> =f <br /> I4 <br />