Appendix D JWPCP Background and NDN

Transcription

1 Appendix D JWPCP Background and NDN

2 JWPCP Background

3 JWPCP Water Quality Primary Clarifiers HPO Reactors Final Clarifiers Unit Influent Primary Effluent Secondary Effluent BOD mg/l <5 COD mg/l TSS mg/l NH 4 -N mg N/L TKN mg N/L TP mg P/L

4 HPOAS Process 8 Treatment Units (Each Unit: Reactor + 26 Final Clarifiers) Currently Operating 6 Treatment Units Parameter Unit Design Current Operation Average Flow MGD Reactor Hydraulic Retention Time (HRT) Hours RAS Recycle Ratio % MLSS mg/l 4,000 3,300 Final Clarifiers Overflow Rate gpd/ft Solids Loading Rate lb/ft 2 -d Mean Cell Residence Time (MCRT) Days MCRT (Reactor Only) Days Aerobic MCRT (Reactor Only) Days

5 Operate HPOAS to Nitrify Only Minimum aerobic MCRT: o C, o C Operating aerobic MCRT: 5 8 days for reliable nitrification Need to increase MLSS by decreasing sludge wasting high MLSS could cause solids loading to exceed design criteria for clarifiers Operate one more treatment unit One unit operated at <50 MGD (35 MGD?) More oxygen required 270 tons/d O 2 used for COD stabilization Additional 250 tons/d O 2 required to fully nitrify Existing HPOAS plants rarely operated in single-sludge nitrification mode

6 Nitrification and Denitrification (NDN) Internal Mixed Liquor Recycle Anaerobic Aerobic Aerobic Aerobic Final Clarifiers RAS Recycle Modified Ludzack-Ettinger (MLE) Configuration Parameter Unit Water Reclamation Plants JWPCP HRT Hours MLSS mg/l 4,000 6,000 3,300 MCRT Days RAS Recycle % Internal ML Recycle % None Significant derating expected (50 MGD 25 MGD?)

7 NDN without Derating (MBR Treating Primary Effluent) Anoxic Recycle Anaerobic Aerobic Aerobic Aerobic Membranes in Existing Clarifiers MLSS: 8,000 10,000 mg/l MCRT: 15 days Aerobic Recycle Sludge Wasting Significant modifications of existing systems (pumping, membranes) Expensive

8 MBR Fully Nitrifies JWPCP Effluent UF RO JWPCP Secondary Effluent MBR RO UV AOP Effluent Hydrogen Peroxide

9 Water Quality - MBR vs. UF Parameter Units JWPCP Effluent MBR Permeate UF Permeate ph (Field) Ammonia mg N/L 37 < TKN mg N/L 40 < Nitrate mg N/L < <0.10 Nitrite mg N/L Phosphate mg P/L COD mg/l TOC mg/l Alkalinity, Total mg CaCO 3 /L

10 Summary of MBR Advantages Removes biodegradable organic matter and degrades some trace organics Better water quality feed to RO RO permeate TOC always < 0.5 mg/l Fully nitrifies secondary effluent less acid needed for ph adjustment upstream of RO Less fouling, less cleaning time vs. UF Membranes can be operated at 23 gfd (similar to UF membranes treating non-ndn secondary effluent)

11 Nitrify JWPCP Effluent Upstream of UF-RO with Biological Aerated Filter (BAF) BAF UF RO JWPCP Secondary Effluent MBR RO UV AOP Effluent Hydrogen Peroxide

12 Biological Aerated Filter o Up-flow reactor with proprietary media for biofilm attachment o Applications: nitrogen removal with simultaneous particle removal o Several manufacturers (Kruger, IDI, BKT)

13 BAF Operations o Up-flow filtration (operation) o Gravity based down-flow backwash o Particles are filtered by the floating media Influent Operation Effluent Backwash

14 BKT s BAF Pilot System One column for nitrification and one for denitrification (need external electron donor) Expanded polypropylene media Title 22 approved for tertiary filtration

15 Schematic Diagram Nitrification Denitrification Backwash Backwash Acetic Acid

16 Operating Conditions of Nitrifying BAF Parameters Units Flow (gpm) Empty Bed Contact Time min Hydraulic Loading Rate gpm/ft NH 4 -N Loading Rate lb N/1000 ft 3 -d Kg/m 3 -d DO mg/l 5.0~6.5 Temperature F 78~93

17 Nitrification Capacity of Nitrifying BAF

18 Nitrifying BAF Performance Parameters Units Influent Effluent Average Min Max Average Min Max NH 4 -N mg N/L < NO 3 -N mg N/L ND NO 2 -N mg N/L ND Alkalinity mg CaCO 3 /L COD mg/l BOD mg/l TSS mg/l Turbidity NTU

19 90 Nitrifying BAF COD Removal Influent COD Influent; Med. = 52 mg/l Intermediate Tank Effluent; Med. = 47 mg/l 60 COD (mg/l)

20 Nitrifying BAF TSS Removal Influent (Median = 10) Influent; Med. = 10 mg/l Effluent; Med. = 8.3 mg/l Intermediate Tank (Median = 8.3) 25 TSS (mg/l)

21 Summary JWPCP s HPOAS system is not designed for nitrification or biological nitrogen removal; upgrade would result in substantial derating or significant costs. JWPCP effluent can be nitrified separately; options include MBR or nitrifying BAF followed by UF. MBR-RO-AOP has been extensively tested and has a number of advantages.

22 Wastewater Treatment Facilities Map Lancaster Palmdale Valencia Saugus Sanitation Districts of Los City Angeles of County Los Angeles D.C. Tillman L.A. Glendale So. Bay Cities 4 Hyperion La Canada 5 JWPCP Whittier Narrows San Jose Creek 18 Los Coyotes 19 Long Beach 22 Pomona 21 Trunk Sewers 9 Terminal Island

23 JOINT WATER POLLUTION CONTROL PLANT - JWPCP Photo of Early Plant Operation

24 Aerial View of the JWPCP 285 MGD N

25 JWPCP Treatment Areas N Biosolids Handling Primary Secondary

26 JWPCP PROCESS FLOW

27

28 Primary Treatment Area CCPP Circular Digesters

29 Inlet Works

30 Aerated Grit Chambers & Inlet Pumps

31 PRIMARY SEDIMENTATION TANKS & SECONDARY INFLUENT PUMP STATION

32 Anaerobic Digesters

33 Power Generation

34 Two Stage Treatment of Air in Primary Treatment Biotrickling Filters + Activated Carbon Biotrickling Filters Activated Carbon

35 Secondary Treatment SEPS Chlorine Station Reactors Clarifiers

36 Secondary Treatment Reactors & Clarifiers

37 Reactor Influent Force Main Reactors A B C D E F G H Clarifiers Effluent Channel

38 JWPCP Secondary Oxygen and Liquid Process Flows Arrangement No. 1 Mixed Liquor To 2 o Clarifiers Liquid Stage Numbers First-Stage 1 SubSurface Mixers { Vent { { { Gas Out High-Purity Oxygen Gas In Primary Effluent and Return Activated Sludge

39 JWPCP Secondary Oxygen and Liquid Process Flows Arrangement No. 2 Air In Mixed Liquor To 2 o Clarifiers Air Out Vent Gas Out Liquid Stage Numbers First-Stage 1 SubSurface Mixers { { { { High-Purity Oxygen Gas In Primary Effluent and Return Activated Sludge

40 Activated Sludge Process

41 Cryogenic Oxygen Separation Plants

42 JWPCP Tunnel/Outfall 2 Tunnels 4 Outfalls 2 miles out Over 160 feet below surface

43 Solids Handling Facility Dewatering Building Truck Loading Stations Biosolids Silos Biofilters

44 Dewatering Building

45 Truck Loading Stations

46 Biosolids Handling Facility Biofilters

47 Questions?