Industry Update on Nitrogen Removal
Programs Across the United States:
What Does it Mean for New England?
March 3rd, 2011
...
Outline
1

Water Industry Sustainability

2

National Perspective - Nitrogen and Hypoxia

3

Massachusetts Estuaries
Nitro...
Water Industry Sustainability

3
Sustainability is in Vogue

4
Focus of Sustainability has been on Energy
● Energy Audits
● Energy Optimization
● Renewable Energy
Sources

5
Sustainability Balancing Act

Nitrogen

Water Supply /
Wastewater Effluent

Green Energy
Carbon Footprint
6
National Perspective on
Nitrogen and Hypoxia

7
Nitrogen is an Emerging National Concern

8
Nitrogen’s Impact on the Ecosystem

Source: evworld.com
9
Chesapeake Bay Oxygen Depletion

Source: evworld.com
10
Long Island Sound Nitrogen Control Program
● In 1998, CT, NY, and EPA agreed to reduce
human sources of N by 58.5% by 2014...
Long Island Sound

12
Source: CTDEP and Long Island Sound Study
The Mississippi River Carries A lot of Nitrogen

13
And the Gulf of Mexico Pays the Price…

Source: evworld.com
14
Historical Development of Nitrogen Limits

10
9

Chesapeake Bay

Long Island Sound, NYC

8 mg/l

8
7

TMDL
(mg/l)

6

Long...
Massachusetts Estuaries

16
Mass Estuaries also have nitrogen concerns

17
Mass Nitrogen Reduction Program Goals
» Reduce ‘N’ to estuaries
» Consider centralized and decentralized
approaches
» High...
Western Cape Recharge Basins

Source: USGS
19
Mass. DEP: Groundwater Discharge Program
(314 CMR 5.00)
Requirements


Meet secondary treatment effluent limits:
» Nitrat...
Treatment Approaches?
● Decentralized Advanced Septic Systems
● Biological Treatment
● Centralized MF/RO, (AOP?) – Concent...
Regulations for Indirect Potable Reuse
Florida

Mass.

10 ppm*

10 ppm*

5 ppm

10 ppm

1 ppm

TOC

3 ppm

3 ppm
1 ppm

0....
Nitrogen Treatment

23
Nitrification / Denitrification Activated
Sludge Process - MLE
TKN = 30 mg/L
TP = 7 mg/L

Aeration Tanks

3Q
Pretreated
Wa...
BNR Step Feed Configuration
TWO-STEP FEED PROCESS

Step Feed
Secondary
Clarifiers

Pretreated
Wastewater

Anoxic

Aerobic ...
BNR Process Configurations – 5-stage
Typical 5-stage BNR Process – Lower TN limit
Carbon
Secondary
Clarifier
Wastewater
An...
3+ Stage with Denitrification Filters
TN < 3 mg/L
Acetate

Methanol

Secondary
Clarifier
Wastewater
Anaerobic Anoxic

Aero...
Denitrification Filters
● Nitrified secondary effluent sent to filtration
● Filter media used to grow an attached biomass ...
Membrane Bioreactor (MBR)
Typical MBR Process

29
Integrated Fixed Film Activated Sludge
(IFAS)
● Media held in Aeration Basins to provide
attached growth for Nitrifying bi...
IFAS in Nutrient Removal
ANA

ANOX AEROBIC

•Higher capacity in same
volume
•“Modular” phasing
•Improved wet weather
stabi...
TZ Osborne WRF – Pilot Layout
RAS

To Final
Clarifier No. 7

Primary
Effluent

IFAS
Cell 1

~ 35% fill (AK-K3)
3 distinct ...
IFAS Pilot Results / Lessons Learned
● Effective nitrification in
approximately half the
aerobic volume
● Dynamic microbia...
BioMag

From CWT Website http://cambridgewatertech.com/technology/biomag
34
Typical Process Treatment Train for Ultra-Low
UltraNutrient Standards

35
Cost vs. Nitrogen Removal

Cost ($)

Nitrogen Removal (mg/L)
36
Nitrogen Removal Option Summary*

2-Stage
BNR

4/54/5-Stage
BNR
+ Carbon
Feed

4/54/5-Stage
BNR
+ Denite
Filters

4/5-Stag...
Supplemental Carbon

38
Available Supplemental Carbon Sources
● Methanol
● Ethanol
● Acetic acid
● Corn syrup/sugar
● Glycerin
● MicroC™
● Primary...
Methanol Considerations
● Benefits
» Low cost (relative to alternatives)
» Low yield (low solids production)
» Proven tech...
41

www.methanex.com

Mar-09

Sep-08

Mar-08

Sep-07

Mar-07

Sep-06

Mar-06

Sep-05

Mar-05

Sep-04

Apr-04

Oct-03

Apr-...
Glycerin
● Typically byproduct of
biodiesel production
● Benefits
» Faster kinetics

● Drawbacks
» Potential for product
i...
Alternative Carbon Testing
Parameter

NRWWTP

HCWRF

Size (mgd)
Feed point
Basins fed
carbon
Control
(if
applicable)

75

...
Parkway WWTP
CHLORINE
CONTACT
BASINS

INFLUENT PUMP
STATION
RAS
PUMP
STATION

SECONDARY
CLARIFIERS

BNR BASIN #2
(RB2)
GRI...
Parkway Full-Scale Pilot Data
Full■ No Acclimation Period Required
Full Scale Pilot Data

1/26/2008

1/19/2008

1/12/2008
...
Cell
1

Cell 2

Cell 3

3848-047

Primary
Anoxic/
Aerobic Zone

Cell 4

Cell 5

Secondary
Anoxic/
Aerobic Zone

Aerobic Zo...
Henrico County WRF Plant Effluent Nitrogen
Profile vs. Substrate Feed Rate
● Sugar water and glycerin both effective.

47
North Carolina “Conventional”
Case Studies

48
Neuse River WWTP, Raleigh, NC
● 60 mgd Advanced WWTP
» Primary Clarifiers
» 4-stage BNR w/ methanol
addition
» Denitrifica...
Neuse River –
4-stage w/ denitrification filters
Typical Operating Parameters

50
Neuse River - Operation and Performance
● Most TN Removal in BNR Basins
● Filters “Trimming” ± 1 mg/L (~ 5 mg/L Methanol D...
High Point, NC – 26 mgd, 5-stage process
mgd, 5-

52
53
EFF TN

No alum or ferric
10/29/2008

7/31/2008

5/2/2008

2/2/2008

11/4/2007

8/6/2007

5/8/2007

2/7/2007

11/9/2006...
Major Recycle Impacts
● Solids handling recycle streams
» Filtrate, centrate, gravity thickener
overflow
● Frequency of re...
Florida “Advanced”
Case Studies

55
Florida vs. Mass Estuary Nitrogen Challenge
● FL - Existing Ocean Outfalls and Septic Tanks
● Cape – Mostly Septic Tanks
●...
Historically, South Florida’s sole source supply
(the Biscayne Aquifer), was fiercely protected
Effluent
Reuse

Class I
De...
Existing Supply Limited for Utilities

C.E.R.P
No New Water
for the Public
58
Recent Legislation – Ocean Outfall Ban
● Outfall shut down due to nitrogen – Coral Reefs
● Achieve significant TN & TP red...
Legislated Water Reuse Requirements
Lake
Okeechobee

7.7 MGD
6.2 MGD
22.4 MGD
24.1 MGD
48.6 MGD
68.9 MGD

Total = 178 MGD
...
Recharging Groundwater is Essentially a Surface
Water Discharge – nitrogen concerns

County / Local Issues

61
Miami Dade County

62
Miami South District
Water Reclamation Plant
● 1st indirect potable reuse project in Florida
● Recharge drinking water aqu...
Emerging Contaminants
Pharmaceuticals

Personal
Care Products

64

Endocrine
Disrupting Compounds
Advanced Oxidation Processes (AOPs)
High dosage UV w/ H2O2
UV ~ 500 mj/cm2
H2O2 ~ 1-3 ppm

UV – TiO2
Ozone
65
Hydroxyl Radical (OH°) is a very strong oxidant!

OXIDIZING SPECIES

RELATIVE OXIDATION
POTENTIAL (V)

Hydroxyl Radical

2...
Miami Dade South District WRP

Miami-Dade County
Miami-

67
Example of the complexities
Moat

Drainage Canal

Regional Canal

Proposed
Biscayne Wells

68

Note: Locations are concept...
Biscayne National Park is Environmentally
Sensitive

69
Groundwater Recharge Criteria

Miami Dade
County

Florida
State
Standard

TOC

--

3 mg/l

Total Suspended Solids (TSS)

-...
Precedent Setting Treatment Levels

71
Plantation, FL Pilot Study

72
WWTP Located Near Canal That Could
Recharge the Biscayne Aquifer

Plantation
WWTF

East Holloway
Canal

East
Wellfields
Ce...
Pilot Goals
● Demonstrate technology
can meet water quality
» TN
» TP
● Unregulated Parameters
» Microconstituents
» Toxic...
Things to consider

75
Nutrient Control
● What is the
technology
necessary to meet
the stringent TN &
TP limits?
● Biological vs
Chemical nutrien...
Aquatic Organism Impact
● Whole effluent
toxicity (WET)
tests
● Is the RO
permeate toxic?
● Will the effluent
cause any
ho...
Microconstituents
● Which
microconstituents are
in your wastewater?
● What technology will
most effectively
remove them?
●...
Recharge Modeling
● Does your
point of
discharge “offset” your
withdrawal
impacts?
● Can you get a
1/1 credit?
● What happ...
Sustainability
● Is this really
sustainable?
● Water Supply
vs Carbon
Footprint?

80
Public Outreach
● How do you
change the “Sewer
to Tap” mentality?
● How do you
involve the public
early in the
project?

8...
Costs
● Capital cost
● Energy costs

82
Plantation Pilot

83
Broward County
Canal Recharge Effluent Limits
Parameter

Effluent Limit

TN

< 1.5 mg/L

TP

< 0.02 mg/L

Nitrate

< 10 mg...
MBR Scheme

85
Conventional Treatment Scheme

86
MBR Scheme Data

87
Plantation AWT MBR Scheme
MBR Pilot

88

RO/UV
Pilot Trailer
Total nitrogen removal of
MBR and RO Pilot Units

89
Total phosphorus removal of
MBR and RO Pilot Units

90
Conventional Treatment Data

91
Plantation AWT Conventional
Treatment Scheme
Denitrification
Filter Pilot

92

UF/RO/UV
Pilot Trailer
Total nitrogen removal of
Deep Bed Filter and RO Pilot Units

93
Total phosphorus removal of
Deep Bed Filter and RO Pilot Units

94
Conclusions – Nutrient Removal

● Both pilots met stringent TN & TP limits
● RO membranes are necessary to meet TP limit
●...
Microconstituents

96
What are Microconstituents?
● Pharmaceutically Active Compounds (PhAC)
» Ethynyl Estradiol
» Sulfamethaxazole
● Personal C...
Concentration (ng/l)

Microconstituents –
RO Influent Concentrations

98
Concentration (ng/l)

Microconstituents – Most were
removed by RO membranes

99
Aquatic Organism Toxicity Testing

100
Is the RO permeate toxic?
● RO permeate is too clean
» RO re-stabilization/re-mineralization
» Added salts and minerals
● ...
Does RO Pre-treatment
Preaffect toxicity?
● RO Pre-treatment
» Antiscalant
» Chloramines
● Pilot Results
Fatheaded Minnow
...
Summary
● The pilot demonstrated to meet stringent nutrient
limits at different test conditions.
● RO membranes are necess...
University of Connecticut
Advanced Reuse Project

104
University of Connecticut Reuse Project

105
This is a Spotlight Project

106
Potential Uses of Reclaimed Wastewater
Reuse
Facility ►

▼ WWTP

◄ Power Plant

107

◄ Irrigation Sites ►
Process Flow Diagram

108
UCONN Reclaimed Water Facility
University of Connecticut
– Reclaimed Water Facility
Location

Storrs, CT

Capacity

1.0 mg...
MF System Design Criteria
Parameter
Type

Pressurized

System Rated Capacity

1 mgd

No. of MF Units

3

No. of Membrane M...
UV System Design Criteria
Parameter
Type

LPHO

System Rated Capacity

1 mgd

No. of UV Systems

2+1

UV Design Dose

80 m...
Sustainability Features
● Replaces as much as
40% of water supply at
times
● Reclaimed water
reservoir used as a
heating s...
Constructed New Facility?

113
Summary and Conclusions

114
Summary and Conclusions
● Nitrogen control programs are growing
● Very low nitrogen requires significant energy and $
● Ra...
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Industry update on nitrogen removal programs across the United States: What does it mean for New England?

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An industry update on nitrogen removal programs across the United States. Presented by Rick Cisterna, Senior Associate with Hazen and Sawyer during the Buzzards Bay Coalition's 2011 Decision Makers Workshop series. Learn more at www.savebuzzardsbay.org/DecisionMakers

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Industry update on nitrogen removal programs across the United States: What does it mean for New England?

  1. 1. Industry Update on Nitrogen Removal Programs Across the United States: What Does it Mean for New England? March 3rd, 2011 Richard H. Cisterna, P.E. Cisterna, P.E. 1
  2. 2. Outline 1 Water Industry Sustainability 2 National Perspective - Nitrogen and Hypoxia 3 Massachusetts Estuaries Nitrogen Treatment Technology Overview 4 5 Conventional and Advanced Case Studies 6 2 Summary and Conclusions
  3. 3. Water Industry Sustainability 3
  4. 4. Sustainability is in Vogue 4
  5. 5. Focus of Sustainability has been on Energy ● Energy Audits ● Energy Optimization ● Renewable Energy Sources 5
  6. 6. Sustainability Balancing Act Nitrogen Water Supply / Wastewater Effluent Green Energy Carbon Footprint 6
  7. 7. National Perspective on Nitrogen and Hypoxia 7
  8. 8. Nitrogen is an Emerging National Concern 8
  9. 9. Nitrogen’s Impact on the Ecosystem Source: evworld.com 9
  10. 10. Chesapeake Bay Oxygen Depletion Source: evworld.com 10
  11. 11. Long Island Sound Nitrogen Control Program ● In 1998, CT, NY, and EPA agreed to reduce human sources of N by 58.5% by 2014. A TMDL was developed and approved by EPA in 2001. 11
  12. 12. Long Island Sound 12 Source: CTDEP and Long Island Sound Study
  13. 13. The Mississippi River Carries A lot of Nitrogen 13
  14. 14. And the Gulf of Mexico Pays the Price… Source: evworld.com 14
  15. 15. Historical Development of Nitrogen Limits 10 9 Chesapeake Bay Long Island Sound, NYC 8 mg/l 8 7 TMDL (mg/l) 6 Long Island Sound, CT North Carolina 5 mg/l 5 4 3 mg/l 3 2 1.5 mg/l 1 Florida 0 1990 15 2000 2010 2020
  16. 16. Massachusetts Estuaries 16
  17. 17. Mass Estuaries also have nitrogen concerns 17
  18. 18. Mass Nitrogen Reduction Program Goals » Reduce ‘N’ to estuaries » Consider centralized and decentralized approaches » Highly treat wastewater to new Massachusetts DEP Standards » Strategically recharge reclaimed water 18
  19. 19. Western Cape Recharge Basins Source: USGS 19
  20. 20. Mass. DEP: Groundwater Discharge Program (314 CMR 5.00) Requirements  Meet secondary treatment effluent limits: » Nitrate as Nitrogen < 10 mg/L » Total Nitrogen < 10 mg/L » Fecal Coliform < 200 colonies per 100 mL All Discharges  Discharges within Zone II or IWPA Effluent shall be filtered to meet: » TSS » Turbidity » TOC  Discharges within Zone II or IWPA and 2 year Travel Time < 10 mg/L < 5 NTU < 3 mg/L Effluent shall be oxidized, filtered, disinfected and coagulated to meet: » TSS » Turbidity » BOD < 5 mg/L < 2 NTU < 10 mg/L » TOC < 1 mg/L » Fecal Coliform = avg. of zero colonies per 100 mL over a continuous 7 day sampling period; no single sample shall exceed 14 colonies per 100 mL = 5 Log Inactivation and/or Removal or 20 Direct Injection (into saturated zone) » Virus  Disinfection shall not be waived.  Coagulation may be waived if meet turbidity requirement with filtration alone.
  21. 21. Treatment Approaches? ● Decentralized Advanced Septic Systems ● Biological Treatment ● Centralized MF/RO, (AOP?) – Concentrate Issue ● MF, GAC, (AOP?) 21
  22. 22. Regulations for Indirect Potable Reuse Florida Mass. 10 ppm* 10 ppm* 5 ppm 10 ppm 1 ppm TOC 3 ppm 3 ppm 1 ppm 0.5 ppm --- 1 ppm Emerging Contaminants No/Yes No? Yes No/Yes Yes Nitrogen California Arizona * Local requirements can be more stringent 22 Australia
  23. 23. Nitrogen Treatment 23
  24. 24. Nitrification / Denitrification Activated Sludge Process - MLE TKN = 30 mg/L TP = 7 mg/L Aeration Tanks 3Q Pretreated Wastewater Primary Clarifiers NH3-N < 2 mg/L NO3-N < 5 mg/L TN = 8 mg/L TP = 5 mg/L Secondary Clarifiers Anoxic Air Blowers Secondary Effluent Aerobic Return Sludge Primary Sludge Waste Activated Sludge N&P Removal ● Solids in primary sludge (5 - 10 %) ● Biosynthesis in WAS (10 - 20 %) ● Denitrification (40 - 60 %) 24 TN ~ 8 to 10 mg/L
  25. 25. BNR Step Feed Configuration TWO-STEP FEED PROCESS Step Feed Secondary Clarifiers Pretreated Wastewater Anoxic Aerobic Anoxic Secondary Effluent Aerobic RAS TN ~ 6 to 9 mg/L Waste Activated Sludge FOUR - STEP FEED PROCESS Secondary Clarifiers Pretreated Wastewater Secondary Effluent Anoxic Aerobic Anoxic Aerobic Anoxic Aerobic Anoxic Aerobic RAS 25 TN ~ 4 to 6 mg/L Waste Activated Sludge
  26. 26. BNR Process Configurations – 5-stage Typical 5-stage BNR Process – Lower TN limit Carbon Secondary Clarifier Wastewater Anaerobic Primary Anoxic Aerobic Secondary Anoxic BNR Aeration Tank Secondary Effluent Reaeration WAS TN ~ 3 to 4 mg/L 26
  27. 27. 3+ Stage with Denitrification Filters TN < 3 mg/L Acetate Methanol Secondary Clarifier Wastewater Anaerobic Anoxic Aerobic BNR Aeration Tank WAS 27 Granular Media Filter Secondary Effluent
  28. 28. Denitrification Filters ● Nitrified secondary effluent sent to filtration ● Filter media used to grow an attached biomass that will denitrify the secondary effluent ● Supplemental carbon addition ● Good solids removal + denite – 2 gpm/ft2 28
  29. 29. Membrane Bioreactor (MBR) Typical MBR Process 29
  30. 30. Integrated Fixed Film Activated Sludge (IFAS) ● Media held in Aeration Basins to provide attached growth for Nitrifying biomass ● Typical Floating and Fixed IFAS Media » Kaldnes (plastic) » Linpor (sponge) » Ringlace (cord) 30 30
  31. 31. IFAS in Nutrient Removal ANA ANOX AEROBIC •Higher capacity in same volume •“Modular” phasing •Improved wet weather stability 31 ANOX
  32. 32. TZ Osborne WRF – Pilot Layout RAS To Final Clarifier No. 7 Primary Effluent IFAS Cell 1 ~ 35% fill (AK-K3) 3 distinct zones 32 IFAS Cell 2 IFAS Cell 3 Screens for each cell Isolation / throttle air valve for each cell
  33. 33. IFAS Pilot Results / Lessons Learned ● Effective nitrification in approximately half the aerobic volume ● Dynamic microbial population ● Higher air usage ● Screen headloss higher than expected ● Foam handling a must ● Influent screening must be sized correctly (i.e. opening size) 33 Biomass on Media (gTSS/m2 of media surface) 30 25 20 15 10 5 0 04/01/08 06/13/08 08/25/08 11/06/08 01/18/09 04/01/09 Date Cell D Biomass Cell E Biomass Cell F Biomass
  34. 34. BioMag From CWT Website http://cambridgewatertech.com/technology/biomag 34
  35. 35. Typical Process Treatment Train for Ultra-Low UltraNutrient Standards 35
  36. 36. Cost vs. Nitrogen Removal Cost ($) Nitrogen Removal (mg/L) 36
  37. 37. Nitrogen Removal Option Summary* 2-Stage BNR 4/54/5-Stage BNR + Carbon Feed 4/54/5-Stage BNR + Denite Filters 4/5-Stage 4/5BNR + MBR w/ Carbon Feed 4/5-Stage 4/5BNR + UF + NF or RO TN effluent Achievable 8 - 12 mg/L 3 - 6 mg/L 3 - 4 mg/L 2 - 3 mg/L < 1.5 mg/L Capital Cost per GPD $0.25 - $1.25 $0.50 - $2.00 $1.25 - $2.50 $2.50 - $3.00 $3.00 - $4.00 40 kW 50 kW 55 kW 100 kW 125 kW $21k - $28k $30k - $40k $35k - $47k Criteria Energy Usage per MGD Annual O&M Cost per MGD $121k - $161k $261k - $348k *Relative cost for additional treatment only. Total cost will depend on the available plant infrastructure. 37
  38. 38. Supplemental Carbon 38
  39. 39. Available Supplemental Carbon Sources ● Methanol ● Ethanol ● Acetic acid ● Corn syrup/sugar ● Glycerin ● MicroC™ ● Primary fermentate 39
  40. 40. Methanol Considerations ● Benefits » Low cost (relative to alternatives) » Low yield (low solids production) » Proven technology ● Drawbacks » Requires specialist population ■ Slow growing » Volatile price » Slower kinetics » Flammable 40 Recent Methanol Accident Site at Bethune Point WWTP
  41. 41. 41 www.methanex.com Mar-09 Sep-08 Mar-08 Sep-07 Mar-07 Sep-06 Mar-06 Sep-05 Mar-05 Sep-04 Apr-04 Oct-03 Apr-03 Oct-02 Apr-02 Oct-01 Apr-01 Methanol Price ($/Gallon) Methanol Costs – 2001 to 2009 (Expect Price Fluctuations) $3.00 $2.50 $2.00 $1.50 $1.00 $0.50 $0.00
  42. 42. Glycerin ● Typically byproduct of biodiesel production ● Benefits » Faster kinetics ● Drawbacks » Potential for product inconsistencies with waste products » Viscous in cold weather » Specialist population not required ● Products » Brenntag » Unicarb-DN » BioCarb DN (Denite-1) » MicroC-Glycerin » Waste products 42
  43. 43. Alternative Carbon Testing Parameter NRWWTP HCWRF Size (mgd) Feed point Basins fed carbon Control (if applicable) 75 75 One All Substrate 43 PWWTP SDWRF NDWRF 7.5 Second anoxic zone All 20 20 One 4 out of 5 One parallel Full-scale Full-scale One parallel One parallel basin that evaluation, evaluation, basin that basin that was fed therefore no therefore no was not fed was not fed methanol control control carbon carbon Glycerin Sugar water Glycerin Glycerin Glycerin and glycerin
  44. 44. Parkway WWTP CHLORINE CONTACT BASINS INFLUENT PUMP STATION RAS PUMP STATION SECONDARY CLARIFIERS BNR BASIN #2 (RB2) GRIT REMOVAL PRIMARY CLARIFIERS BNR BASIN #1 (RB1) SOLIDS HANDLING 44 MLR PUMP STATION
  45. 45. Parkway Full-Scale Pilot Data Full■ No Acclimation Period Required Full Scale Pilot Data 1/26/2008 1/19/2008 1/12/2008 45 Effluent NOx Effluent TN Brenntag Glycerin 7 per. Mov. Avg. (Effluent NOx) 7 per. Mov. Avg. (Effluent TN) Carbon dose, gal/day 0 1/5/2008 0 12/29/2007 20 12/22/2007 1 12/15/2007 40 12/8/2007 2 12/1/2007 60 11/24/2007 3 11/17/2007 80 11/10/2007 4 11/3/2007 100 10/27/2007 120 5 Concentration (mg/L) 6
  46. 46. Cell 1 Cell 2 Cell 3 3848-047 Primary Anoxic/ Aerobic Zone Cell 4 Cell 5 Secondary Anoxic/ Aerobic Zone Aerobic Zone Cell 6 Cell 7 Cell 8 R eAeration Zone Prim ary A noxic/ Anaerobic Zone Anaerobic Zone RA S Ferm entation Henrico VA Cell 9 Cell 10 Cell 11 Cell 12 Cell 13 NRCY RAS M istributionC LD hannel PED istributionChannel RA SPipeline BNR Tank 8 NRCY RAS BNR Tank 7 NRCY RAS BNR Tank 6 NRCY RAS To Secondary Clarifier No. 8 BNR Tank 5 ML Distribution Channel RAS/WAS Pump Station RAS 46 To Secondary Clarifier No. 7
  47. 47. Henrico County WRF Plant Effluent Nitrogen Profile vs. Substrate Feed Rate ● Sugar water and glycerin both effective. 47
  48. 48. North Carolina “Conventional” Case Studies 48
  49. 49. Neuse River WWTP, Raleigh, NC ● 60 mgd Advanced WWTP » Primary Clarifiers » 4-stage BNR w/ methanol addition » Denitrification Filters w/ methanol addition ● Largest Plant in Eastern U.S. Achieving LOT for TN Utilizing Conventional Suspended Growth BNR Process ● Upcoming Expansion to 75 mgd » TN = 2.7 mg/L, TP = 1 mg/L ● Calibrated BioWin Model Used to Evaluate/ Optimize Expansion 49
  50. 50. Neuse River – 4-stage w/ denitrification filters Typical Operating Parameters 50
  51. 51. Neuse River - Operation and Performance ● Most TN Removal in BNR Basins ● Filters “Trimming” ± 1 mg/L (~ 5 mg/L Methanol Dose) ● Annual Average Effluent TN = 2.4 mg/L (2004 - 2008) S E a n d F in a l E fflu e n t N itr o g e n C o n c e n tr a tio n s 6 ● 2007 Annual Average Effluent TN = 1.96 mg/L Concentration (mg/L) 5 4 3 2 1 EFF TN SE TN 3 0 p e r. M o v . A v g . (E F F T N ) 3 0 p e r. M o v . A v g . (S E T N ) Sep-07 Jul-07 May-07 Mar-07 Jan-07 Nov-06 Sep-06 Jul-06 May-06 Mar-06 Jan-06 Nov-05 Sep-05 Jul-05 May-05 Mar-05 Jan-05 Nov-04 Sep-04 Jul-04 May-04 Mar-04 51 Jan-04 0
  52. 52. High Point, NC – 26 mgd, 5-stage process mgd, 5- 52
  53. 53. 53 EFF TN No alum or ferric 10/29/2008 7/31/2008 5/2/2008 2/2/2008 11/4/2007 8/6/2007 5/8/2007 2/7/2007 11/9/2006 8/11/2006 5/13/2006 2/12/2006 11/14/2005 20 8/16/2005 5/18/2005 2/17/2005 11/19/2004 8/21/2004 5/23/2004 2/23/2004 11/25/2003 8/27/2003 5/29/2003 2/28/2003 11/30/2002 9/1/2002 EFF Total Nitrogen (mg/L) High Point Performance 22 Average Eff TN 1/07 to 12/08 = 3.3 mg/L 18 16 14 12 No supplemental carbon 10 8 6 4 2 0 30 per. Mov. Avg. (EFF TN) Avg TP = 0.18 mg/L Biologically
  54. 54. Major Recycle Impacts ● Solids handling recycle streams » Filtrate, centrate, gravity thickener overflow ● Frequency of return Parameters Plant Recycle Loads (lbs/day) Contribution From Plant Recycles (%) BOD 43,600 2,830 6.5 TSS 39,300 6,590 17 TKN 54 Plant Influent Loads (lbs/day) 5,700 1,620 29 TP 1,280 680 53
  55. 55. Florida “Advanced” Case Studies 55
  56. 56. Florida vs. Mass Estuary Nitrogen Challenge ● FL - Existing Ocean Outfalls and Septic Tanks ● Cape – Mostly Septic Tanks ● Both – High Level Nitrogen Treatment / Recharge 56
  57. 57. Historically, South Florida’s sole source supply (the Biscayne Aquifer), was fiercely protected Effluent Reuse Class I Deep Injection Wells 57 Two Key issues for FDEP: ● Alternate Water Supply Resource ● Environmental enhancement (Nitrogen)
  58. 58. Existing Supply Limited for Utilities C.E.R.P No New Water for the Public 58
  59. 59. Recent Legislation – Ocean Outfall Ban ● Outfall shut down due to nitrogen – Coral Reefs ● Achieve significant TN & TP reductions by 2018 ● “Reuse” 60% of outfall flow by 2025 ● After 2025, outfall for wet weather back-up, w/ nutrient reductions 59
  60. 60. Legislated Water Reuse Requirements Lake Okeechobee 7.7 MGD 6.2 MGD 22.4 MGD 24.1 MGD 48.6 MGD 68.9 MGD Total = 178 MGD 60 South Central Regional Boca Raton Broward Co. North Hollywood Miami-Dade North Miami-Dade Central District
  61. 61. Recharging Groundwater is Essentially a Surface Water Discharge – nitrogen concerns County / Local Issues 61
  62. 62. Miami Dade County 62
  63. 63. Miami South District Water Reclamation Plant ● 1st indirect potable reuse project in Florida ● Recharge drinking water aquifer with 23 mgd of highly treated wastewater ● Addressing pharmaceuticals and pathogens with regulators and public ● MF, RO, UV-AOP ● Ultra-pure drinking water quality 63
  64. 64. Emerging Contaminants Pharmaceuticals Personal Care Products 64 Endocrine Disrupting Compounds
  65. 65. Advanced Oxidation Processes (AOPs) High dosage UV w/ H2O2 UV ~ 500 mj/cm2 H2O2 ~ 1-3 ppm UV – TiO2 Ozone 65
  66. 66. Hydroxyl Radical (OH°) is a very strong oxidant! OXIDIZING SPECIES RELATIVE OXIDATION POTENTIAL (V) Hydroxyl Radical 2.05 Ozone 1.52 Hydrogen Peroxide 1.31 Permanganate 1.24 Chlorine Dioxide 1.15 Chlorine 1.00 Data from Metcalf & Eddy, 2003 66 Increasing ability to degrade pollutants
  67. 67. Miami Dade South District WRP Miami-Dade County Miami- 67
  68. 68. Example of the complexities Moat Drainage Canal Regional Canal Proposed Biscayne Wells 68 Note: Locations are conceptual. Intended for discussion purposes only
  69. 69. Biscayne National Park is Environmentally Sensitive 69
  70. 70. Groundwater Recharge Criteria Miami Dade County Florida State Standard TOC -- 3 mg/l Total Suspended Solids (TSS) -- 5 mg/l Total Nitrogen (TN) -- 10 mg/L Ammonia 2.8 mg/l 0.5 mg/l -- Total Phosphorus (TP) .003 mg/l -- Yes No Parameter Emerging Contaminants 70
  71. 71. Precedent Setting Treatment Levels 71
  72. 72. Plantation, FL Pilot Study 72
  73. 73. WWTP Located Near Canal That Could Recharge the Biscayne Aquifer Plantation WWTF East Holloway Canal East Wellfields Central Wellfields 73
  74. 74. Pilot Goals ● Demonstrate technology can meet water quality » TN » TP ● Unregulated Parameters » Microconstituents » Toxicity » Algal growth potential » Hormonal impacts 74
  75. 75. Things to consider 75
  76. 76. Nutrient Control ● What is the technology necessary to meet the stringent TN & TP limits? ● Biological vs Chemical nutrient removal ● Are RO membranes necessary? 76
  77. 77. Aquatic Organism Impact ● Whole effluent toxicity (WET) tests ● Is the RO permeate toxic? ● Will the effluent cause any hormonal impacts? 77
  78. 78. Microconstituents ● Which microconstituents are in your wastewater? ● What technology will most effectively remove them? ● Are microconstituents really a concern at these concentrations (ng/L)? 78
  79. 79. Recharge Modeling ● Does your point of discharge “offset” your withdrawal impacts? ● Can you get a 1/1 credit? ● What happens during the wet season? 79
  80. 80. Sustainability ● Is this really sustainable? ● Water Supply vs Carbon Footprint? 80
  81. 81. Public Outreach ● How do you change the “Sewer to Tap” mentality? ● How do you involve the public early in the project? 81
  82. 82. Costs ● Capital cost ● Energy costs 82
  83. 83. Plantation Pilot 83
  84. 84. Broward County Canal Recharge Effluent Limits Parameter Effluent Limit TN < 1.5 mg/L TP < 0.02 mg/L Nitrate < 10 mg/L Ammonia TSS < 5.0 mg/L CBOD5 < 10.0 mg/L BOD 84 < 0.02 mg/L < 5.0 mg/L
  85. 85. MBR Scheme 85
  86. 86. Conventional Treatment Scheme 86
  87. 87. MBR Scheme Data 87
  88. 88. Plantation AWT MBR Scheme MBR Pilot 88 RO/UV Pilot Trailer
  89. 89. Total nitrogen removal of MBR and RO Pilot Units 89
  90. 90. Total phosphorus removal of MBR and RO Pilot Units 90
  91. 91. Conventional Treatment Data 91
  92. 92. Plantation AWT Conventional Treatment Scheme Denitrification Filter Pilot 92 UF/RO/UV Pilot Trailer
  93. 93. Total nitrogen removal of Deep Bed Filter and RO Pilot Units 93
  94. 94. Total phosphorus removal of Deep Bed Filter and RO Pilot Units 94
  95. 95. Conclusions – Nutrient Removal ● Both pilots met stringent TN & TP limits ● RO membranes are necessary to meet TP limit ● Membranes alone (UF/RO) with no chemical addition met TN & TP limits 95
  96. 96. Microconstituents 96
  97. 97. What are Microconstituents? ● Pharmaceutically Active Compounds (PhAC) » Ethynyl Estradiol » Sulfamethaxazole ● Personal Care Products (PCP) Ethynyl Estradiol » Triclosan » Toiletries, cosmetics, fragrances ● Endocrine Disrupting Compounds (EDC) » Bisphenol-a » Atrazine » DEET 97 DEET Triclosan
  98. 98. Concentration (ng/l) Microconstituents – RO Influent Concentrations 98
  99. 99. Concentration (ng/l) Microconstituents – Most were removed by RO membranes 99
  100. 100. Aquatic Organism Toxicity Testing 100
  101. 101. Is the RO permeate toxic? ● RO permeate is too clean » RO re-stabilization/re-mineralization » Added salts and minerals ● How would this work full scale? » Dilution » Mixing zone 101
  102. 102. Does RO Pre-treatment Preaffect toxicity? ● RO Pre-treatment » Antiscalant » Chloramines ● Pilot Results Fatheaded Minnow 102 Water Flea
  103. 103. Summary ● The pilot demonstrated to meet stringent nutrient limits at different test conditions. ● RO membranes are necessary for surface water discharge due to stringent TP limits. ● Almost all microconstituents were removed by RO system. ● RO permeate could be toxic re-stabilization/remineralization is necessary. ● The observed toxicity to aquatic organisms was likely caused by chloramines. Other forms of RO pretreatment should be evaluated. 103
  104. 104. University of Connecticut Advanced Reuse Project 104
  105. 105. University of Connecticut Reuse Project 105
  106. 106. This is a Spotlight Project 106
  107. 107. Potential Uses of Reclaimed Wastewater Reuse Facility ► ▼ WWTP ◄ Power Plant 107 ◄ Irrigation Sites ►
  108. 108. Process Flow Diagram 108
  109. 109. UCONN Reclaimed Water Facility University of Connecticut – Reclaimed Water Facility Location Storrs, CT Capacity 1.0 mgd Technology Microfiltration + UV Disinfection + Chloramination Application • Cooling Tower Make-Up Water • Boiler Feed Water (post RO treatment) • Irrigation Unique Challenges 109 • Corrosion & Scaling Control for Cooling Towers
  110. 110. MF System Design Criteria Parameter Type Pressurized System Rated Capacity 1 mgd No. of MF Units 3 No. of Membrane Modules per Unit 32 Membrane Type 0.1 micron PVDF Specific Design Flux 39 gfd Minimum Recovery Percent 110 Value 91%
  111. 111. UV System Design Criteria Parameter Type LPHO System Rated Capacity 1 mgd No. of UV Systems 2+1 UV Design Dose 80 mJ/cm2 UV Transmittance ≥ 65% at 254 nm Effluent Turbidity ≤ 0.2 NTU (95% of the time) Effluent Total Coliform Max. 2.2/100 mL (7 day geometric mean) Suspended Solids Max. 111 Value 5 mg/L
  112. 112. Sustainability Features ● Replaces as much as 40% of water supply at times ● Reclaimed water reservoir used as a heating source ● Stormwater capture and blending with wastewater ● Solar electricity 112
  113. 113. Constructed New Facility? 113
  114. 114. Summary and Conclusions 114
  115. 115. Summary and Conclusions ● Nitrogen control programs are growing ● Very low nitrogen requires significant energy and $ ● Range of treatment options ● Good experiences and resources in other states to draw upon 115
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