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Technical Description <br />(BOD5) (Q, MGD) (8.34 lbs/gal) <br />(125) (0.075) (8.34) <br />78.18 lbs/day <br />Solids inventory in aeration tank <br />MLVDD mg/L) (V, MGD) (8.34 lbs/gal) <br />(1600) (0.50) (8.34) <br />6,672 lbs <br />F:M = 78.18 BOD,/day <br />6672 lbs MLVSS <br />= 0.01 lbs BOD5 /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 />HI = 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 02 = 111.3 mg/L (lbs) of 02 is required for conversion. <br />CLARIFIER SIZING <br />Sedimentation is based upon detention capacity design. Since the entire volume of mixed liquor <br />in aeration standby (batch) is physically transferred into the clarifier, settling time may be adjusted <br />to allow even the smallest particle to settle. <br />Unlike a conventional flowthrough clarifier, where the surface area must be large enough to allow <br />particles to settle downward in a constantly moving stream, the batch clarifier provides particle <br />settling under completely static, quiescent conditions. This method is more efficient and economi- <br />cal than meeting the need in flowthrough systems for greater surface areas with increasing flow <br />rates at larger capacities. <br />With the batch process, the static clarifier does not require this larger surface area; therefore, in <br />design, the batch clarifier volume capacity is equal to the mixed-liquor volume, or batch, to be <br />transferred. <br />Surface Settling Rate (SSR) does apply, however, but only on a batch-by-batch basis. SSR are <br />based upon flow in static conditions and are thus accurate for the 24-hour period flow. The Bio- <br />Pure batch process is unique in that longer retention times are not required to do the accurate <br />sludge volume results obtained in the standard SSV-30 and SSV-60 tests. By staying within those <br />basic design parameters of SSR per batch, the static condition of the batch clarification process is <br />directly comparable to settleometer readings.