ISAM SBR with Blower Assisted Jet Aeration Design Calculations For Lyons, CO WWTP Upgrade

Transcription

1 ISAM SBR with Blower Assisted Jet Aeration Design Calculations For Lyons, CO WWTP Upgrade May. 28, 2013 A. Site Conditions 1. Site elevation = 5,322 ft MSL 2. Average barometric pressure = psia 3. Temperature Max Min B. Process Design Parameters a. Wastewater = 20 C 10 C b. Air = 100 F 0 F 1. Design Flow = MGD 2. Average Daily Flow = 0.25 MGD 3. Peak Hourly Flow = 0.95 MGD (Assumed) 4. Peak Instantaneous Flow = 661 GPM (Assumed) 5. Influent Loading a. BOD 5 = 222 mg/l = 705 lb/day 1) Removed in anaer. chamber = 30% 2) BOD to SBR = 494 lb/day b. TSS = 260 mg/l = 826 lb/day 1) Removed in anaer. chamber = 60% 2) TSS to SBR = 330 lb/day c. TKN = 35 mg/l (Assumed) = 111 lb/day d. NH 3 -N = 23 mg/l = 73 lb/day 6. Effluent Limits a. BOD 5 = 30 mg/l b. TSS = 30 mg/l c. NH 3 -N = 1 mg/l d. Total N = 10 mg/l (Estimated) C. Sludge production and Solids Reduction 1. Design Aerobic SRT = 22 days ISAM Blower Page 1 Version: 4.0 : 04/13

2 2. lb VSS/lb BOD 5 T DES = lb VSS/lb NH 3 -N T DES = lb VSS/lb NO 3 -N T DES = MLVSS/MLSS = 80% 6. Total SBR sludge T DES = 236 lb/day 7. Total SBR sludge T MIN = 266 lb/day 8. MASS required = 6,361 lb 9. Sludge concentration > 9,000 mg/l 10. SBR WAS T DES = 3,144 gal/day 11. SBR WAS T MIN = 3,542 gal/day 12. Solids reduction a. Wastewater temperature = 12 C 10 C b. Anaerobic volatile reduction > 50% 50% = 94 lb/day 106 lb/day c. Waste sludge concentration > 4.0% 4.0% d. Sludge to disposal = 142 lb/day 160 lb/day e. Inerts in anaerobic chamber = 149 lb/day 149 lb/day f. Sludge volume to disposal = 870 gpd 924 gpd g. Sludge storage = 73 days 69 days D. Nitrification/Denitrification Calculations 1. Average DO for BOD & nitrification = 1.0 mg/l 2. Alkalinity required for nitrification = 105 mg/l 3. Alkalinity recovered, denitrification = 14 mg/l 4. Net influent alkalinity required = 91 mg/l 5. Max. nitrifier growth rate = days^-1 6. Min. SRT required for nitrification = 8.0 days 7. Aerobic SRT at T MIN = 19.4 days 8. Kn, half velocity constant = mg/l 9. Des. growth rate for heterotrophs = Projected effluent soluble NH 3 -N = 0.16 mg/l 11. Specific utilization rate = MLVSS for BOD & NH 3 removal = 3,295 lb 13. Design MLSS = 3,000 mg/l 14. Design MLVSS = 2,400 mg/l 15. Aerobic reactor volume required = MG 17. Aerobic reactor F:M = Anoxic reactor volume = MG ISAM Blower Page 2 Version: 4.0 : 04/13

3 19. Specific denitrification rate at T MIN = g/g/day 20. Maximum NO 3 removed at T MIN = 38 lb/day 21. NO 3 removal required = 15 lb/day 22. Total tank volume required = MG 23. Actual tank volume provided = MG E. Reactor Basin Sizing 1. Aerobic reactor sizing 2 b. TWL = 18 ft 0 in c. BWL = 13 ft 0 in d. Length = 44 ft 0 in a. Width = 21 ft. 6 in a. Aerobic reactor volume = MG a. Aerobic HRT = 16.0 hr 2. Anoxic reactor sizing 2 b. TWL = 12 ft 0 in c. BWL = 2 ft 0 in c. Length = 15 ft 0 in d. Width = 30 ft 0 in e. Anoxic reactor volume = MG f. Anoxic HRT = 5.1 hr 3. Anaerobic reactor sizing 2 b. SWD = 9 ft 6 in c. Length = 30 ft 0 in d. Width = 30 ft 0 in e. Anaerobic reactor volume = 0.13 MG f. Anaerobic HRT = 8.1 hr 4. Effluent equalization 1 b. TWL = 11 ft 6 in c. BWL = 2 ft 0 in c. Length = 44 ft 0 in d. Width = 15 ft 0 in e. Equalization working volume = MG ISAM Blower Page 3 Version: 4.0 : 04/13

4 F. Oxygen Calculations 1. Actual Oxygen Demand a. lbs. O 2 / lb. BOD 5 removed = 1.25 b. lbs. O 2 / lb. NH 3 -N oxidized = 4.60 c. lbs. O 2 recovered/ lb. NO 3 denitrified = 2.86 d. Actual Oxygen Requirement = 670 lb/day 2 AOR to SOR Conversion Formula C SMID a. SOR = AOR (T -20) b C SMID - C L aq 0.5 (S) C S b. Where: a = 0.85 b = 0.95 T = 20 C q = C S = 9.09 mg/l C L = 1.00 mg/l = Oxygen saturation concentration at 50 % submergence at site elevation and temperature. C SMID = 9.61 mg/l 3. Standard Oxygen Required (Average) = 1,090 lb/day a. Peaking factor = Standard Oxygen Required (Peak) = 1,471 lb/day G. Equipment Design 1. Calculate Cycles Average Load Peak Load 2. Aeration Design a. Cycle time at design flow = 4.46 hr 4.46 hr b. Fill time (anoxic) = 0.59 hr 0.59 hr c. Aerated interact = 2.04 hr 2.41 hr d. Anoxic interact = 0.49 hr 0.11 hr e. Settle time = 0.75 hr 0.75 hr f. Decant time = 0.59 hr 0.59 hr g. Total cycle time = 4.46 hr 4.46 hr a. Submergence = 16.0 ft 16.0 ft b. Total aeration time = 2.04 hr/cycle 2.41 hr/cycle = hr/day hr/day c. SOR for aeration design = 50 lb/hr 57 lb/hr d. Design gassing rate = 41 SCFM/jet 50 SCFM/jet ISAM Blower Page 4 Version: 4.0 : 04/13

5 e. Site gassing rate = 50 ICFM/jet 61 ICFM/jet f. Absorption efficiency = 23.4% 22.0% g. Design air flow = 205 SCFM 249 SCFM h. Jets required per basin = 5 5 i. Aerators per basin = 1 1 j. Jets per aerator = 5 5 H. Blower Calculations 1. Operating blowers = Air flow per blower = 205 SCFM 250 SCFM 3. Inlet losses = 0.50 psig 0.50 psig 4. Net inlet pressure = psia psia 5. Discharge piping losses = 0.50 psig 0.50 psig 6. Aerator losses = 7.03 psig 7.03 psig 7. Total discharge pressure = 7.53 psig 7.53 psig 8. Design ambient temperature = 100 F 100 F = 560 R 560 R 9. Site air flow required = 280 ICFM 340 ICFM 10. Equivalent sea level pressure = psig psig 11. Assumed blower efficiency = 57% 57% 12. BHp/blower = Total blower BHp = Blower Motor Hp = J. Pump Calculations 1. Motive Liquid Pumps a. Pumps per basin = 1 1 b. Flow per pump = 1,000 GPM 1,000 GPM c. Total pump head = 27 ft 27 ft d. Assumed pump efficiency = 70% 70% e. BHp per pump = f. Total pump BHp = g. Pump motor Hp = K. Decanter Sizing 1. Cycles per day = Batch volume = 35,380 35, Decant flow = 1,000 GPM 1,000 GPM ISAM Blower Page 5 Version: 4.0 : 04/13

6 L. Summary 1. Standard Oxygen Required = 1,090 lb/day 1,471 lb/day 2. Total BHp = Power usage = 376 kwh/day 500 kwh/day ISAM Blower Page 6 Version: 4.0 : 04/13