活性污泥法设计.xls

Activated Sludge Process Design Example no nitrification 1 Design Information Flow rate Q 20 000m3 d average day Influent BOD5 S0 200mg L soluble Influent VSS X0 0mg L Effluent BOD5 Se 20mg L Effluent SS 20mg L Effluent VSS Xe 13mg L Effluent BOD5 S 7 4mg L soluble Growth yield Y 0 5g VSS g BOD5 Decay rate kd 0 06day 1 MLVSS MLSS 0 8 Wasted sludge concentration XW 8 000mg L Plant altitude 100m Design temperature T 25 oC 2 Aeration Basin Select MCRT qX 10days Select MLVSS X 2 000mg L MLSS 2 500mg L Observed yield Yobs Y 1 kdqX 0 313 Increase in VSS PX YobsQ S0 S 1 203kg d Increase in SS PXM 1 504kg d Mass balance of wasted sludge PXM Q QW SS QWXW QW PXM Q SS XW SS 138m3 d Solids in wasted sludge 1 107kg d Solids lost in effluent 397kg d Reguired basin volume V PXqX X 6 017m3 Select basin depth D 5 0m Reguired basin area A V D 1 203m3 Select basin length L 40m Reguired basin width W A L 30m3 Check F M ratio QS0 VX 0 33day 1 Check HRT Q V 7 2hour 3 Oxygen and Air Requirement Influent BODU SS1 294mg L Effluent BODU SS 11mg L ThOR Q SS1 SS 1 42 PX 3 954kg d SelectCsw 9 08mg L C sw 8 24mg L C 2 0mg L a 0 8 b 0 9 Fa 1 altitude 9450 0 99 SOR ThOR C swbFa C Csw 1 024 T 20 a 7 469kg d Air density r PM RT 1 184kg m3 Select OTE 25 SAR SOR r 0 232 OTE 108 740 m3 d 76m3 min Select SF 1 5 AR SAR x SF 113m3 min 4 Circular Secondary Clarifier Select overflow rate 22m3 m2 d Necessary area for sedimentation 909m2 Select clarifier diameter 20m Area of one clarifier 314m2 Min clarifier number 3 provide additionl 1 clarifier for standby Total clarifier area 942 Actual overflow rate 21m3 m2 d Select clarifier depth 4 0m Select RAS ration 0 3 Check HRT 3 5hour Check solid loading rate 2 9kg m2 h Activated Sludge Process Design Example with nitrification 1 Design Information Flow rate Q 20 000m3 d average day Influent BOD5 S0 200mg L soluble Influent VSS X0 0mg L Effluent BOD5 Se 20mg L Effluent SS 20mg L Effluent VSS Xe 13mg L Effluent BOD5 S 7 4mg L soluble Influent NH3 N SNH1 40mg L Effluent NH3 N SNH 0mg L Growth yield YH 0 5 YA 0 22 Decay rate kd 0 06day 1 MLVSS MLSS 0 8 Wasted sludge concentration XW 8 000mg L Plant altitude 100m Design temperature T 25 oC 1 1 Nitrification Evaluation Selectm A 0 75day 1 C 2 0mg L KOA 0 5mg L bA 0 10day 1 qX 10days m A m AC KOA C 0 60day 1 qmX 1 m A bA 2 0 fSA qX qmX 5 0Thus nitrification happens 2 Aeration Basin Select MCRT qX 10days Select MLVSS X 2 000mg L MLSS 2 500mg L Observed yield Yobs Y 1 kdqX 0 313 Increase in VSS PXH YobsQ S0 S 1 203kg d Reguired basin volume V PXHqX X 6 017m3 Select basin depth D 5 0m Reguired basin area A V D 1 203m3 Select basin length L 40m Reguired basin width W A L 30m3 SelectYA 0 22 Neglect N comsumed for cell synthesis PXA YA Q NOX 1 bAqX 88kg d PXT PXH PXA 1 291kg d Increase in MLSS PXMT 1 614kg d Mass balance of wasted sludge PXMT Q QW SS QWXW QW PXMT Q SS XW SS 152m3 d Solids in wasted sludge 1 217kg d Solids lost in effluent 397kg d 3 Oxygen and Air Requirement Influent BODU SS1 294mg L Effluent BODU SS 11mg L ThOR Q SS1 SS 4 57 Q SNH1 SNH 1 42 PXT 7 485kg d SelectCsw 9 08mg L C sw 8 24mg L C 2 0mg L a 0 8 b 0 9 Fa 1 altitude 9450 0 99 SOR ThOR C swbFa C Csw 1 024 T 20 a 14 138kg d Air density r PM RT 1 184kg m3 Select OTE 25 SAR SOR r 0 232 OTE 205 838 m3 d 143m3 min Select SF 1 5 AR SAR x SF 214m3 min 4 Circular Secondary Clarifier Select overflow rate 22m3 m2 d Necessary area for sedimentation 909m2 Select clarifier diameter 20m Area of one clarifier 314m2 Min clarifier number 3 provide additionl 1 clarifier for standby Total clarifier area 942 Actual overflow rate 21m3 m2 d Select clari