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Extended aeration detention sizing: <br /> NOTES <br /> Fxh <br /> Hl = C (7) <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 NH,expected:27.5 <br /> Desired: 275—26.5 = 94.5%removed <br /> so 26.5 x 4.2 OZ = 111.3 mg/1(lbs) of OZ is required for conversion. <br /> CLARIFIER SIZING <br /> Sedimentation is based upon detention capacity design. Since the <br /> entire volume of mixed liquor in aeration standby is physically trans- <br /> ferred into the clarifier, settling time may be adjusted to allow even <br /> the smallest particle to settle. <br /> Unlike a conventional flowthrough clarifier, where the surface area <br /> must be large enough to allow particles to settle downward in an up- <br /> flow stream, the batch clarifier provides particle settling under com- <br /> pletely static, quiescent conditions. This method is more efficient <br /> and economical than meeting the need in flowthrough systems for <br /> greater surface areas with increasing flow rates at larger capacities. <br /> With the batch process, the static clarifier does not require this <br /> larger surface area; therefore, in design, the batch clarifier volume <br /> capacity is equal to the mixed-liquor volume to be transferred. <br /> Surface settling rates (SSR) do apply, however, but only on a batch- <br /> by-batch basis.SSRs are based upon flow in static conditions and are <br /> thus accurate for the 24-hour period flow. <br /> The AquaClear batch process is unique in that longer retention <br /> times are not required to do the accurate sludge volume indexing <br /> obtained in the standard SSV-30 and SSV-60 tests. <br /> By staying within those basic design parameters of SSR per batch, <br /> the static condition of the batch clarification process is directly com- <br /> parable to settleometer readings. <br /> Complete control of the entire process can be based upon the SSV- <br /> 30 and-60 tests. If the sludge flocculates well and settles rapidly, it is <br /> possible to manually program the system controller (PC) to allow for <br /> automatic sequencing of the batch cycle based upon current biomass <br /> conditions within the treatment plant. This change can increase or <br /> decrease aeration detention and the subsequent clarifier cycle sur- <br /> face settling rate. <br /> 16 <br />