Domestic Wastewater Treatment Mobilization Construction - AskTOP

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EM 1110-3-17211 May 84by means of a turbine mixer . Table 11-3 lists power requirementsassociated with various types of aerators .Table 11-3 .Power Requirementsfor DifferentTypes of AeratorsType of Aeration SystemOxygenDeliveredpounds 02/hp/hourPowerRequiredkW-hour/pounds2Diffused Air, Fine-Bubble 2 .1 0 .35Diffused Air, Coarse-Bubble 1 .4 0 .55Mechanical'Aerator, Vertical 3 .7 0 .20Shaft (Surface Aerator)Agitator Sparger System 2 .1 0 .3511-5 . Aeration tank design .a . Number and arrangement of aeration tanks . If the total aerationtank volume exceeds 5,000 cubic feet, except for the extended aerationprocess, the total capacity will be divided into two or more unitscapable of independent operation . Diffused-air aeration tanks,rectangular in shape, will be divided into one or more channels in sucha manner that the length of travel exceeds four times the width of thechannels . Inlets and outlets for each aeration tank will be suitablyequipped with valves, gates, stop plates, weirs, or other devices tofacilitate control of the flow and liquid levels in the tank . Channelsand pipes carrying liquids with solids in suspension will be designedto maintain self-cleaning velocities (i .e ., not less than 2 'fps) .Devices for-indicating flow rates of raw sewage or-primary effluent,return sludge, and air to each aeration tank 'will 'be provided .b . Aeration tank volume . Aeration tank'"volumg must satisfy thefol1'owing criteria (if more than one of these-A .is y applicable in a givensituation, the most stringent must be . satisfied) :(1) A 'minimum detention time (aeration time),'is``stated'inparagraph 11-3 .'' (2) The limitation of volumetric loading (pounds "BdDh ,b00 cubicfeet/day) .' (3`)' The' limitation of organic' loading expressed in . poundsBOD/day/pound MLVSS .~(4) A desirable ratio .of pound B06/poiifid MUSS is to bemaihiained"in° the' veration tank .:- Thi# ratio` will range from 0 .25- to0 .5 in conventional plants and from 0 .2 to 6 .5 in Step Aeration and
EM 1110-3-17211 May 84Contact Stabilization . For extended aeration, this ratio variesbetween 0 .03 and 0 .2 .(5) An optimum BOD-to-nutrient ratio of 100 :5 :1 of BODNitrogen : Phosphorus is to be maintained for proper microbiologicalgrowth . <strong>Domestic</strong> wastewater does not need any supplemental nutrients,but if some industrial wastes encumber the system, some nutrientaddition may be required .c . Aeration tank dimensions .(1) Conventional activated sludge . Minimum tank depth,side-water depth, (SWD), will be 7 to 10 feet for small plants (0 .1mgd) and from 10 to 14 feet for larger plants ; minimum free board willbe 2 feet . The tank bottom will slope along the longitudinal axis to asump . Aeration tank width will be 1 .65 to 2 .0 times the SWD ; thelarger ratio is the width used for deeper tanks . For'example, a tankwith a SWD of 10 feet will be 16 .5 feet wide, while a tank with a SWDof 15 feet will be 30 feet wide . However, these limitations do notapply to a completely mixed system .(2) Completely mixed activated sludge . Aeration tanks will bedesigned in a manner to insure proper turbulent flow of wastewater .For diffused-air systems, the air diffusers will be installed along oneside of the channel and near its bottom . The opposite bottom cornerwill have a fillet of concrete, and deflector baffles (at an angle ofapproximately 45 degrees) placed at the water surface so as to assistin maintaining the desired circulation of liquid in the tank . Thetraverse velocity across the bottom of these tanks should be at least 1fps and preferably 1 .5 fps in order to prevent deposition of solids inthe tank bottom . For mechanical aerator systems, the installedhorsepower should not exceed 2 .5 hp/1,000 cubic feet of the tank'sliquid volume . The minimum liquid depth will be 10 feet and themaximum depth 12 feet . Draft-tube aerators must be used for depthsgreater than 12 feet, and the largest horizontal distance of the unitfrom wall to wall will be 24 feet . If circular tanks are used formechanical aeration systems, internal wall baffles will be provided inorder to prevent potential vortexing problems . If more than oneaerator is required for an aeration basin, the minimum center-to-centerspacing of the units, in feet, will be 0 .8 times the unit aeratorhorsepower .11-6 . Final settling tank . It will be the function of the finalsedimentation tank to remove solids from the aeration tank effluent .The final sedimentation tank will be designed to handle a flow equal tothe projected design raw wastewater flow . The design will provide forthe sludge return to the aeration tank . The design parametersindicated in paragraphs 8-3 .b . and 8-4 . should be observed .
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EM 1110-3-17211 May 84ParagraphPage
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Vadophil - Auction No. : 18Lot No.
Page 14 and 15:
Table 3-1 . Evaluation of Wastewate
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Table 3-1 . Evaluation of Wastewate
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Table 3-2 . Approximate Performance
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EM 1110-3-17211 May 844-3 . Estimat
Page 23 and 24: EM 1110-3-17211 May 84c . Industria
Page 25 and 26: EM 1110-3-17211 May 84d . Treatment
Page 27 and 28: EM 1110-3-17211 May 84CHAPTER 5SELE
Page 29 and 30: EM 1110-3-17211 May 84zWJWWWU . S .
Page 31 and 32: EM 1110-3-17211 May 84CHAPTER 6FLOW
Page 33 and 34: EM 1110-3-17211 May 84WATER SURFACE
Page 35 and 36: EM 1110-3-17211 May 847-1 . General
Page 37 and 38: EM 1110-3-17211 May 84channel shoul
Page 39 and 40: EM 1110-3-17211 May 84_cfs = net ar
Page 41 and 42: EM 1110-3-17211 May 848-3 . Design
Page 43 and 44: EM 1110-3-17211 May 8410080QWQW60NO
Page 45 and 46: EM 1110-3-17211 May 84(2) Weir rate
Page 47 and 48: EM 1110-3-17211 May 84Table 8-3 .Ty
Page 49 and 50: No Discharge DischargeSeries-parall
Page 51 and 52: EM 1110-3-17211 May 84dispersed oxy
Page 53 and 54: EM 1110-3-17211 May 84a . Inlet . I
Page 55 and 56: EM 1110-3-17211 May 84CHAPTER 10TRI
Page 57 and 58: SINGLE-STAGEREM 1110-3-1721 1 May 8
Page 59 and 60: EM 1110-3-17211 May 84(5) Periphera
Page 61 and 62: EM 1110-3-17211 May 84K20 = Treatab
Page 63 and 64: EM 1110-3-172'll May 84Table 10-3 .
Page 65 and 66: EM 1110-3-17211 May 84CHAPTER 11ACT
Page 67 and 68: EM 1110-3-17211 May 84RAW14ASTEWATE
Page 69 and 70: EM 1110-3-17211 May 84being wasted
Page 71 and 72: EM 1110-3-17211 May 84a . Air requi
Page 73: EM 1110-3-17211 May 84with unique,
Page 77 and 78: EM 1110-3-17211 May 8412-3 . Sludge
Page 79 and 80: EM 1110-3-17211 May 84Table 12-1 .A
Page 81 and 82: EM 1110-3-17211 May 84Table 12-3 .H
Page 83 and 84: EM 1110-3-17211 May 84requirements
Page 85 and 86: EM 1110-3-1721 1 May 84b . Landfill
Page 87 and 88: EM 1110-3-1721 1 May 84Table 13-1 .
Page 89 and 90: EM 1110-3-17211 May 84(2) Inspectio
Page 91 and 92: EM 1110-3-17211 May 84CHAPTER 14SMA
Page 93 and 94: EM 1110-3-17211 May 84CHAPTER 15SAF
Page 95 and 96: EM 1110-3-17211 May 84g . A portabl
Page 97 and 98: EM 1110- 3-17211 May 84Weight Remov
Page 99 and 100: EM 1110-3-17211 May 84requirements
Page 101 and 102: EM 1110-3-17211 May 84With a filter
Page 103 and 104: E14 1110-3-17211 May 84Overall effi
Page 105 and 106: EM 1110-3-17211 May 84therefore,0 .
Page 107 and 108: EM 1110-3-17211 May 84Aeration requ
Page 109 and 110: EM 1110- 3-17211 May 84Gas yield =
Page 111 and 112: 1110-3-172' .1'i1 May 8-4Pressure a
Page 113 and 114: SM '11,10-1-472may 84be needed unde
Page 115 and 116: EM 1110-3-17211 May 84APPENDIX BOXY
Page 117: Ek'1110-i;, 3-;47211 May 84Chlorine
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Domestic Wastewater Treatment Mobilization Construction - AskTOP

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