Recurring harmful algal blooms in Lake Erie and other water bodies keep nutrients at the forefront of water quality priorities in the Great Lakes, Upper Mississippi River and elsewhere in the Midwest. Recent regulatory strategies have focused on nonpoint source controls and more stringent point source limits. In response, more treatment utilities will likely consider biological nutrient removal (BNR) technologies along with other alternatives. Since the invention of the Phoredox and Bardenpho processes in South Africa in the early 1970s, understanding of underlying BNR mechanisms has grown significantly, especially for enhanced biological phosphorus removal (EBPR).
This webinar will look at recent developments that have further improved the reliability and cost-effectiveness of EBPR for cold and wet conditions encountered in the Midwest and Great Lakes. Case studies will be discussed demonstrating innovative design features that can turn unintended BNR consequences into positive results, including:
Side-stream EBPR (S2EBPR) – moves anaerobic zones out of the main liquid stream. This configuration is much more reliable and efficient than conventional mainstream anaerobic zones, making EBPR viable in more cases than previously thought possible.
Struvite recovery processes – minimizes nuisance scaling in digestion and dewatering, reduces nutrient return loads to the main liquid stream, improves biosolids dewaterability, and produces a high-quality, eco-friendly fertilizer product.
Step-feed anoxic zones – are a lower-energy denitrification alternative to the traditional Modified Ludzack-Ettinger (MLE) approach to offset nitrification oxygen and alkalinity demands and avoid clarifier sludge blanket flotation.
Wet-weather step-feed and biomass transfer – manage peak flows and protect biomass from washout. Auxiliary enhanced high-rate treatment (EHRT) facilities offer even greater resiliency and excellent phosphorus removal.
More Affordable, Reliable and Recoverable Nutrient Removal
1. Jim FitzpatrickSenior Process Engineer
More Affordable, Reliable and
Recoverable Nutrient Removal
James Barnard Global Practice & Technology Leader
October19,2016
2. • Drivers
• Optimize conventional treatment
• Avoid unintended consequences
• Wet-weather strategies
• Closing thoughts and open discussion
Agenda
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
2
4. Phosphorus freshwater harmful algal blooms (HAB)
Nitrogen Estuary and marine eutrophication and hypoxia
Near and far.
Large and small.
Point and non-point.
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
http://water.usgs.gov/nasqan/images/nasqan_ms_web.jpg
Lake Erie, 2011
FromMDEQ(2016)AlgalToxin
MonitoringinMichiganInland
Lakes:2015Results
5. Case-by-case watershed studies
• Prevent internal reservoir nutrient cycling
A. Keep reservoir mixed/aerated. Prevent stratification.
B. Supply nitrates, air, and/or oxygen to hypolimnion. Occoquan Reservoir etc.
Cubas et al., Water Environment Research, Feb 2014, 123-133.
Sometimes nitrates actually decrease HAB
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Source:http://wetlandinfo.ehp.qld.gov.au/wetlands/ecology/
6. “The phosphorus content of our land, following generations of cultivation, has greatly
diminished. It needs replenishing. I cannot over-emphasize the importance of
phosphorus not only to agriculture and soil conservation, but also the physical health
and economic security of the people of the nation. Many of our soil deposits are
deficient in phosphorus, thus causing low yield and poor quality of crops and
pastures…."
-President Franklin D. Roosevelt, 1938
Increasing population requires better
phosphorus management
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
7. Return to
agricultural
roots
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
From K. Ashley et al. A brief history of phosphorus:
From the philosopher’s stone to nutrient recovery
and reuse. Chemosphere (2011),
doi:10.1016/j.chemosphere.2011.03.001
7
8. 2012 Great Lakes Water Quality Agreement
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
From https://www.epa.gov/glwqa/recommended-binational-phosphorus-targets#what-targets
Reduce spring TP and
OP loads 40% to
control cyanobacteria
Reduce TP loads 40% to
control hypoxic “Dead Zone”
Additional research to
address excess Cladophora
10. • Increased monitoring, research, and planning
• Integrated and adaptive watershed management
1. Agricultural Best management practices (BMPs)
2. Urban stormwater CSO control, wet-weather flow treatment
3. POTWs Tiered point source limits (BNR, ENR, LOT, etc.). TP generally higher
priority than TN for GLUMR states.
4. Watershed trading
State regulatory strategies
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
11. Not a substitute for project-specific alternatives
evaluations and opinions of probable costs
• Low hanging fruits:
• TP removal POTW
• TN removal Agriculture (sometimes POTW)
Historical costs of different practices
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Source: WEF (2015) The Nutrient Roadmap, Figures 5.12 and 5.13
13. • Precipitation and floc adsorption
— Iron (ferrous, ferric)
— Aluminum (alum, PACl, aluminate)
— Calcium (lime)
— Magnesium
• Clarification / filtration
• Media adsorption / ion exchange
• Chemicals + UF membranes
• Reverse osmosis
• Air or steam stripping
• Ion exchange
• Break-point chlorination
• Activated carbon
Many alternatives for nutrient removal
13
BNR = Biological Nutrient Removal.
Phosphorus and nitrogen.
PHOSPHORUS CONTROL NITROGEN CONTROL
Physical/
Chemical
Processes
Biological
Processes
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Struvite Precipitation
• Ammonification (hydrolysis)
• Nitrification
• Denitrification
• Deammonification (anammox)
Enhanced Biological Phosphorus
Removal
• “Luxury Uptake”
• “Bio-P Removal”
• Phoredox (AO)
14. Applying BNR lessons from Mother Nature
14“We’ve come a long way, baby” - Loretta Lynn, 1978
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Barnard
introduces
PhoRedox &
Bardenpho in
South Africa
U.S. patents
for A/O, A2O,
etc.
Primary sludge
fermentation
in northwest
U.S. and
Canada
Deammonification
Struvite Recovery
1970’s 1980’s 1990’s 2000’s
S2EBPR
2010’s
15. In hindsight…side-stream RAS anaerobic zone,
chemical P recovery, mainstream P uptake
• High-rate activated sludge
• No nitrification
• All influent to aeration basin
• RAS stripper tank
• 30-40 hr SRT
• P release from deep anaerobic conditions
• Supernatant treated with lime
• P removed as calcium hydroxy-apatite, Ca10(PO4)6(OH)2
• Fuhs & Chen find phosphate accumulating
organism (PAO) Acinetobacter
Early phosphorus removal
Aerated Settling
Effluent
Stripper
Wasted
Biomass
Return Biomass
Influent
Wastewater
Lime
P-enriched
Lime Sludge
Phostrip Process (1962)
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
15
16. Barnard’s original pilot had side-stream
anaerobic zone with mixed liquor fermentation
• Fermenter basin not deemed important at the time
• Excellent phosphorus removal resulted that could not be
replicated in laboratory
• Barnard suggested biomass (with PAO) should pass through
anaerobic phase with low ORP to trigger EBPR
• Suggested Phoredox process by adding anaerobic zone
Mixed liquor fermentation (MLF)
Waste
Activated
Sludge
100 m3/d Daspoort Pretoria WWTP Pilot (Barnard, 1972)
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
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17. Researchers found Accummulibacter predominant PAO
L e g e n d
(A) (B)
(C) (D)
Anaerobic Anoxic Aerobic
Reduced Nitrates to Anaerobic zone
Phoredox process flow sheets
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
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18. • Volatile fatty acids (VFAs) drive
EBPR mechanism of phosphate
accumulating organisms (PAO)
• Anaerobic zone required
• Mixture of VFAs required for PAO
to thrive
Conventional EBPR thinking
Acetic
47%
Propionic
40%
Butyric
8%Isobutyric
2%
2-Methylbutyric
1% Isovaleric
1% Valeric
1%
Fermentate Analysis
Wakarusa WRF (Lawrence, KS 2007)
PAO Luxury Uptake Mechanism
(Fuhs & Chen, 1975)
Oxic
(Aerobic)
Anaerobic
VFA
First Fermenter Kelowna BC, 1979
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
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19. 10-mgd WWTP saving
$80,000 per year with
EBPR instead of chemicals
• Collection system odor
control projects “robbed” VFA
• Different alternatives
over 11-yr period:
• Alum
• Molasses (boost rbCOD)
• Fermentation (boost VFA)
• Now ferment in primary
clarifiers, PS fermenter and
anaerobic zones
19
Case study of EBPR optimization
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
10-mgd Eagles Point WWTP
Cottage Grove, MN
20. Example of EBPR + filters:
McDowell Creek WWTP
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
From Schauer, P. and deBarbadillo, C. (2009) Pushing the Envelope with Low Phosphorus Limits, PNCWA
21. Example of chemical P removal + filters:
Northwest Cobb WRF
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
From Schauer, P. and deBarbadillo, C. (2009) Pushing the Envelope with Low Phosphorus Limits, PNCWA
22. Westbank with Fermenter
TN < 6 mg/L
BOD < 5 mg/L
TSS < 2 mg/L
TP < 0.15 mg/L
Westside Regional WWTP, aka “West
Bank WWTP” (West Kelowna, BC)
X
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
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Regional District of
Central Okanagan
23. Westside Regional WWTP
Primary Anaerob Anoxic 1 Anoxic 2 Anoxic 3 Aerobic 1 Aerobic 2 Aerobic 3
5.36 20.56 2.20 1.84 1.60 0.50 0.20 0.03
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
Primary
Anaerob
Anoxic1
Anoxic2
Anoxic3
Aerobic1
Aerobic2
Aerobic3
Phosphorus
mg/L
P uptake in Anoxic and Aerobic Zones
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
23
Tetrasphaera ferment and denitrify. Non-
filamentous variety also PAO.
Non-filamentous
Tetrasphaera
24. • Mixed Liquor Fermenters
• Sacramento, CA
• Olathe, KS
• Pinery AWWTP, CO
• Henderson, NV
• Blue Lake & Seneca WWTP, MN
• Joppatowne, MD
• South Cary, NC
• St. Cloud, MN
Other U.S. examples of
side-stream EBPR (S2EBPR)
Off-line MLF Basin with 5-stage Bardenpho
5.3-mgd Cedar Creek WWTP
(Olathe, Kansas)
S2EBPR Design for 181-mgd BNR
EchoWater Project
(Sacramento, California)
Anaerobic Anaerobic Anoxic
OFFONInfluent
RAS MLR
In-line MLF (Pinery, Henderson, St. Cloud, etc.)
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
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25. S2EBPR retrofits easier than conventional EBPR
S2EBPR in 75+ facilities in 10+ configurations
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
26. Dunlap et al., 2016; Stokholm-Bjerregaard et al., 2015
• Side-stream promotes PAO species
Tetrasphaera, which also ferments higher
carbon to VFA
• Accumulibacter PAO use VFA produced by
Tetrasphaera, which also denitrify under
anoxic conditions
Latest research: S2EBPR performs better
than conventional EBPR
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
• Side-stream protected from wet weather flows
• Why did we miss this until now?
• Tetrasphaera need ORP -300 mV; most anaerobic zones struggle to get -150 mV
• Impossible to achieve with NO3 or DO present
• Turbulence, air entrainment, or coarse bubble
air mixing prevent low ORP
• Mixing energy too high (>0.08 hp/kcf)
• Weak primary effluent dilutes VFA
27. • Static mixing chimney
• Low-speed impellers
Energy efficient mixing is one key
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
RAS
MLR
Primary Effluent
Anaerobic or
Anoxic Zone
Mixing
Chimney
28. IFwe need even lower TP…
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Exceptions to above breakpoints. Case-specific
studies recommended.
WE&T, Oct 2011, pp 52-55
0.01
0.1
1
A-Chemical
ReliableAl,FeorCa
B-Biochemically
ReliableVFA
Aand/orB
+Filtration
TertiarySystem
AnnualAverageEffluentTP(mg/L)
Tertiary Alternatives
• Chemically enhanced settling
/ filtration / DAF
• Media adsorption / IX
• Algal-based activated sludge
• RO membrane
29. Significant sustainability questions about overly
stringent TN limits for POTWs.
• Post anoxic/oxic
• 4 or 5-stage Bardenpho
• Denitrifying filter
• Deammonification vs.
imported carbon
• Point vs. non-point load
reductions. Watershed
nutrient trading?
• Stratified reservoirs
may benefit from
nitrates in hypolimnion for
HAB control (Cubas et al.,
2014).
IF we need even lower TN….
29
AX OX AX
OX
NH3-N: 0.1 to 2 mg/L
TN: 3 to 5 mg/L
TP: 0.5 to 1.5 mg/L
AN
MeOH (usually)
AX OX
NH3-N: 0.1 to 2 mg/L
TN: 3 to 5 mg/L
TP: 0.2 to 0.5 mg/L
MeOH (or equal)
AN
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
30. • Increased process stability
• Biological selector helps prevent sludge bulking,
decrease sludge volume index (SVI).
• Side benefits from denitrification
• Recover some alkalinity. Better nitrification and
effluent buffering.
• Offset some O2 demand. Potentially lower aeration
costs.
• More stable sludge blanket in secondary clarifier.
• Potential nutrient recovery
Other reasons to consider BNR besides
effluent quality
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
32. Important for reaching energy, carbon footprint
and nutrient goals…sustainably.
Causes
• PAOs in WAS
anaerobically release
(PO4)3-, Mg2+ and K+.
• NH4
+ released later
during digestion.
Consequences
• Nutrient recycle
• Struvite scaling
• Vivianite scaling if
Fe2+ present
• Decreased biosolids
dewaterability
Making BNR work with anaerobic digestion
32
From Shimp, G.F.; Barnard, J.L.; Bott, C.B.
It’s always something. Water Environment & Technology,
June 2014, 26(6), 42-47.
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
33. Project-specific evaluation and selection
Struvite Sequestration Struvite Recovery
• Reduce nuisance scaling and deposits
• Reduce P & N recycle loads
• Improve biosolids dewaterability
• Optional fertilizer recovery add-on
• Reduce nuisance scaling and deposits
• Reduce P & N recycle loads
• Decrease P in biosolids
• Recovered fertilizer product
Turn struvite problem into the solution
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
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34. Choices include Ostara Pearl®, MHI Multiform™, CNP AirPrex®,
Schwing Bioset/NuReSys®, KEMA Phred™, and DHV Crystalactor®
Main Goals
• Minimize nuisance
scaling and deposits
• Improve biosolids
dewaterability
• Reduce P & N
recycle loads
• Decrease P content
of biosolids
• Recover fertilizer
product
Struvite recovery/sequestration gaining
traction
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
36. • Minimizes ammonia return
• Digester liquors ideal for anammox
• Advantages to conventional
nitrification/denitrification:
• Much less energy
• No carbon required
• Lower alkalinity demand
Also consider side-stream
deammonification for TN
36
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Leading edge technology for digester return streams
Blue Plains AWTPBlue Plains AWTP
World’s Largest Facility
(DEMON®, Under Construction)
Pilot
■ Henrico, VA
■ Brooklyn, NY
■ Egan WRP, MWRDGC, IL
■ Robert W. Hite WRF, Denver, CO
■ Joint WPCP, Los Angeles County, CA
■ Mill Creek WWTP, Cincinnati, OH
■ St. Joseph, MO
■ Tomahawk WWTF, Johnson County, KS
Full-Scale
■ HRSD, VA
■ Alexandria, VA
■ Greeley, CO
■ Guelph, Ontario, CAN
■ Durham, NC
■ Washington, DC
■ Pierce County, WA
■ Egan WRP, MWRDGC, IL
Since 2012
38. Maximizing biological treatment of wet-weather flows
• Temporary change to contact
stabilization mode for wet-
weather flows
• “Biological contact” or
“biocontact”
• Good fit for plug-flow basins
Deep step-feed helps “weather the storm”
38
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
MJHB with Wet-Weather Step-Feed
AX OX
AN
AX
2Qavg < Q < 3Qavg
Blue River Main WWTP
Johnson County, Kansas
3-stage Modified Johannesburg
39. Another way to reduce SLR to clarifiers… temporarily.
• Transfer some RAS or MLSS to offline storage.
• Return biomass after storm flows pass.
• Good fit for complete-mix baxins, oxidation ditches, etc.
Biomass transfer accomplishes same thing
39
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
MLSS = 1,000 mg/L
(Off-loading MLSS)
MLSS = 2,300 mg/L
MLSS = 2,300 mg/L
BioWin Process Model
of RAS Transfer OperationsOffline Biomass Storage
Rogers, Arkansas
5-stage Bardenpho with Oxidation Ditch
40. Blending or auxiliary treatment for higher
peaking factors
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Backgrounddiagram from: U.S.EPA, Sanitary SewerOverflowsand Peak FlowsListeningSession,June 30, 2010
Backgrounddiagram from: U.S.EPA, Sanitary SewerOverflowsand Peak FlowsListeningSession,June 30, 2010
Auxiliary
41. Great Lakes HRT example
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Toledo, Ohio
Bay View Water Reclamation Plant
232-mgd DensaDeg HRC Facility
• Nitrifying activated sludge
with parallel HRC train
• 45 mgd average dry weather
• 70 mgd annual average
• 400 mgd peak hour
Parameter
Average Effluent
(mg/L, 2007-2009)
TSS 21
CBOD5 22
TP 0.3
42. Consider dual-use for both dry and wet
weather benefits
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Examples include Fox Metro, IL; Johnson County, KS;
Little Rock, AR
COMPRESSIBLEMEDIAFILTRATION
Sludge/Backwash
Primary
Clarifiers
Aeration
Secondary
Clarifiers
HRC or HRF
Degritting
Screening
Disinfection
Primary
Clarifiers
Aeration
Secondary
Clarifiers
HRC or HRF
Degritting
Screening
Disinfection
Aeration
Secondary
Clarifiers
HRC or HRF
Degritting
Screening
Disinfection
Headworks Headworks Headworks
44. BNR at lower cost, lower energy and smaller footprint
Granular activated sludge expands to U.S.
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
• Aqua-Aerobic Systems, Inc.
• Exclusive U.S. supplier
• Full-scale demonstration at Rock River WRD (Rockford, IL)
• Black & Veatch
• Teaming agreement with RHDHV
Granular
Activated
Sludge
Conventional
Activated
Sludge
45. Stay tuned!
• http://www.barleyprize.com/
• #barleyprize
• B&V on judging panel
Seeking radically cheaper
technology for <0.01 mg-P/L
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
46. Site-specific optimization. No one-size-fits-all.
Side-stream EBPR (S2EBPR)
• Increase reliability of chemical-free phosphorus removal
• Increase EBPR feasibility and performance for more process flow sheets
• Lower cost than conventional EBPR
• If anaerobic digestion evaluate struvite recovery and deammonification
Wet-Weather Flows
• Optimize existing facilities with step-feed or biomass transfer
• Consider auxiliary treatment for peaking factors 3
Regulatory Strategy
• Sustainable goals must recognize site-specific water body response, influent
carbon limitations, energy/carbon footprint and nonpoint sources.
• Annual average limits. Daily, weekly, or monthly not practical for
eutrophication concern.
• TP=0 not feasible due to soluble non-reactive phosphorus (sNRP).
• TN=0 not feasible due to recalcitrant dissolved organic nitrogen (rDON).
Total inorganic nitrogen (TIN) limits vs TN. Colorado & Ohio precedence.
Summary
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
46
49. How will we meet growing phosphorus
demand?
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
From S. Van Kauwenbergh. (2010), World Phosphate
Rock Reserves and Resources. Presented at Center for
Strategic and International Studies
Recovery is
part of long-
term solution
49
50. …different fates and ecosystem responses
Different nutrients … different forms …
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Total
Kjeldahl
Nitrogen
(TKN)
NH3-N
ORG-N
rDON
NO2-N
NO3-N
Total
Nitrogen
(TN)
Total
Inorganic
Nitrogen
(TIN)
OP or
PO4-P
ORG-P
Total
Phosphorus
(TP)
Reactive
Phosphorus
sNRP
51. Potentially lower life-cycle costs
Why consider enhanced biological phosphorus
removal (EBPR)?
2.0 1.5 1.0 0.5
RelativeLifeCycleCost
Effluent TP in mg/L
Chemical Addition
Conversion
to EBPR
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
52. Each POTW is different.
• Not just BOD, TSS, NH3-
N and TP
• Influent fractions of
C, N and P species
• VFAs for EBPR
• Readily biodegradable
COD (rbCOD) for
denitrification
• Daily and seasonal
variations
• Bad odors usually
good sign for BNR
Special sampling study for BNR planning and
optimized design
52
0
5
10
15
20
25
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
VFA/rbCOD ratio
rbCOD/OPratio
Reedy Creek (South Carolina)
McDowell Creek (North Carolina)
Reliable EBPR
above the
curve
EBPR model
curveNo
Fermentation
HRSD VIP (Virginia)
Eagles Point WWTP (Minnesota)
With
Fermentation
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
53. • Measure influent TKN
and Ammonia
• RDON can only be
measured from full-scale
or pilot activated sludge
BNR plant to remove all
forms of biodegradable
nitrogen.
• TIN better indicator of
activated sludge
performance than TN.
Nitrogen fractions
Total
Kjeldahl
Nitrogen
(TKN)
NH3-N
ORG-N
rDON
NO2-N
NO3-N
Total
Nitrogen
(TN)
Total
Inorganic
Nitrogen
(TIN)
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
54. • Measure influent OP after
acid digestion to determine
total reactive phosphorus
• sNRP can only be measured
from full-scale or pilot
activated sludge plant.
Phosphorus fractions
OP or
PO4-P
ORG-P
sNRP
Total
Phosphorus
(TP)
Reactive
Phosphorus
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
55. Example of conventional EBPR
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
However…EBPR observed in full-scale facilities
without mainstream anaerobic zone.
OxicCell 1
AnaerobicCell3
effluent
Mixers
24-mgd Clean Water Plant
Wyoming, Michigan
56. Adsorption without metal salt dosing
• Polymeric metal oxide media
developed by Asahi
• In-situ regeneration with NaOH
• Long-term pilots in U.S. and
Japan
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Cross sectionExterior Surface Internal Structure
Fibril
Cavities
Cross sectionExterior Surface Internal Structure
Fibril
Cavities
ExteriorSurface Cross Section Internal Structure
• 0.13-mgd demonstration at Kasumigaura Lake WWTP
(near Tokyo) averaged TP < 0.03 mg/L during first year
• 10-mgd facility on hold, pending ultralow permit limits 56
57. Another S2EBPR example
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
MLE process exhibited EBPR performance
Iowa Hill WWTF (Breckenridge, CO)
0
0.05
0.1
0.15
0.2
0.25
0.3
EffluentOrthoPmg/L
9/8/2011 9/9/2011 9/10/2011
Courtesy: Chris Maher, Upper Blue Sanitation District
58. • Step-Feed Denitrification – No ML recycle pumping, but limits
denite capacity.
• Oxidation Ditch – Bio-denitro™, Oxystream™, Carousel®, and
others. Can use ditch velocity instead of separate pumps to
recycle mixed liquor in some cases.
• Cycled Aeration – alternate anoxic/oxic
• Small Footprint Options
Lots of variations on MLE and BNR themes
October 19, 2016
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Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Suspended Growth Fixed-Film Hybrid
Sequencing Batch Reactor
(SBR)
Biologically Active Filter
(BAF)
Integrated Fixed-Film
Activated Sludge (IFAS)
•Static media
•Moving media
Membrane Bioreactor
(MBR)
Moving Bed Biofilm Reactor
(MBBR)
Magnetite Ballasted
Biomass (BioMag™)
Granular Activated Sludge
59. 3-stage usually offers most bang for buck.
Many different configurations and variations.
Anaerobic Zone
• No DO and no NOX
• Fermentation
• P release
• Biomass selector
MLE process can be added for TN control
59
Anoxic Zone
• DO < 0.5 mg/L
• NOX from ML recycle
• Heterotrophic
denitrification
Oxic Zone
• DO: 2-3 mg/L
• P uptake and removal with WAS
• Autotrophic nitrification
• Heterotrophic BOD removal
OXAnoxic Typical Range (not TBEL)
TP: 0.5 to 1.5 mg/L
NH3-N: 0.1 to 2 mg/L
TN: 6 to 10 mg/L
AN
AX
Mixed Liquor Recycle
Modified Ludzack-Ettinger (MLE)
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60. Site-specific process modeling and cost evaluations
Step-Feed Alternative
• No mixed liquor recycle
pumping lower energy
• Modest denitrification
• O2 & ALK benefits
• Process stability
• Evaluate ammonia bleed-
through
Consider step-feed anoxic zones vs. MLE
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60
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AnoxicAnoxic/Oxic
Swing Zone
Mixers
ML Recycle
Pump
PrimaryEffluent
130-mgd Mill Creek WWTP, Cincinnati, OH
BNR Alternatives Study
0
2
4
6
8
10
12
14
1Q 2Q 3Q 4Q 5Q 6Q 7Q 8Q
EffluentNO3,mg/L
Mixed Liquor Recycle Ratio
Inf TKN = 30 mg/L
61. Tertiary P removal strategies
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61
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Also dissolved air flotation (DAF), algal-based
systems, low-pressure membrane filters (MBR
or tertiary) and reverse osmosis alternatives
A
Chemically
Enhanced
Clarification
and Polishing
Filters
B
Chemically
Enhanced
Two-Stage
Filters
C
Filtration and
Adsorption
Media with P
Recovery
A
Chemically
Enhanced
Clarification
(CEC) and
Polishing
Filters
62. 62
CEC generally involves 4 steps
1. Coagulant Addition. Rapid mix. Add metal salt and/or cationic
polymer to “break” colloids (de-emulsify)
3. Flocculation. Medium to low turbulence.
Build floc and “sweep” small particles into
floc. Enhance floc settling.
4. Clarification. Non-turbulent.
Separate solids from liquids.
2. Flocculant Addition. Rapid mix. Add anionic or nonionic
polymer. Optional if steps 1 and 3 are ideal.
Turbulence
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63. Jar tests to evaluate and guide full-scale optimization
• Coagulation
• Al3+/Fe3+/Ca2+ dose
• Alkalinity/pH
• Rapid mixing criteria
• Flocculation
• Polymer type and dose
• Rapid mixing criteria
• Slow mixing criteria
• Sludge recirculation
Steps 1-3 determine success
63
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• Coagulant dose higher than PO4 precipitation alone
• Metal hydroxyl floc formation
• pH/alkalinity
• Deflocculation from monovalent cations
64. 64
Clarification mechanisms
Gravimetric
Filtration*
* Generally requires particle conditioning, depends upon waste and filter type.
Flotation
Settling
Surface Charge
Neutralization
Coagulation
Co-precipitation
Flocculation
Adsorption
Particle Conditioning
Sieving (Surface) Adsorption (Depth)
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65. CEC example - Durham AWTF (Tigard, OR)
October 19, 2016
65
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Conventional drinking water technologies
Tertiary clarifier with paddle
flocculator Dual media granular filters
66. Other full-scale examples
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66
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Facility
Capacity
(mgd)
Technology
Average
Effluent TP
(mg/L)
Farmers Korner WWTF
(Breckenridge, CO)
3
EBPR, alum, tube settlers,
mixed media filters
0.002 - 0.04
Snake River WWTP
(Summit County, CO)
2.6
Alum, plate settlers, mixed
media filters
<0.01 – 0.04
Rock Creek AWTF
(Hillsboro, OR)
39
EBPR, alum, tertiary clarifiers,
granular media filters
0.04 – 0.09
Durham AWTF (Tigard, OR) 24
EBPR, alum, tertiary clarifiers,
granular media filters
0.05 – 0.1
F. Wayne Hill WRC
(Gwinnett County, GA)
60
EBPR, lime, tertiary clarifiers,
filters, membranes
<0.08
Alexandria AWWTP
(Alexandria, VA)
54
EBPR, ferric, alum, plate
settlers, dual media filters
0.04 – 0.1
Upper Occoquan WRP
(Centreville, VA)
42
High lime clarification,
multimedia granular filters
0.02 – 0.1
Noman Cole WPCP
(Fairfax County, VA)
67
EBPR, ferric, tertiary clarifiers,
dual/mono media filters
0.02 – 0.13
From USEPA (2007) Advanced Wastewater Treatment to Achieve Low Concentration of Phosphorus, EPA 910-R-07-
002 and Schauer, P. and deBarbadillo, C. (2009) Pushing the Envelope with Low Phosphorus Limits, PNCWA
68. Full-scale examples with high-rate CEC
About another 27 DensaDegs, 171 ACTIFLOs, 12
BioMags and 8 CoMags treating wastewater since 1989
Facility
Capacity
(mgd)
Technology
Average
Effluent TP
(mg/L)
Iowa Hill WWTF
(Breckenridge, CO)
1.5
Alum, DensaDeg,
DynaSand filter
0.017 - 0.13
Flat Creek WRF
(Gainesville, GA)
20 EBPR, alum, DensaDeg <0.13
South Lyon CWP (South
Lyon, MI)
4 Alum, Actiflo <0.07
Metro Syracuse WWTP
(Onandaga County, NY)
126 PACl / ferric, Actiflo 0.05 – 0.09
Sturbridge WPCF
(Sturbridge, MA)
1.6
BioMag BNR, alum,
CoMag
0.039
Billerica WWTP
(Billerica, MA)
5.5 Alum, CoMag 0.036
68
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
From USEPA (2007) Advanced Wastewater Treatment to Achieve Low Concentration of Phosphorus, EPA 910-
R-07-002 and case study material from Degremont (2008), Kruger (2012), and Evoqua (2015).
69. Tertiary P removal strategies
October 19, 2016
69
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Also dissolved air flotation (DAF), algal-based
systems, low-pressure membrane filters (MBR
or tertiary) and reverse osmosis alternatives
A
Chemically
Enhanced
Clarification
and Polishing
Filters
B
Chemically
Enhanced
Two-Stage
Filters
C
Filtration and
Adsorption
Media with P
Recovery
B
Chemically
Enhanced
Two-Stage
Filters
70. Blue PRO®: ferric oxide coated sand filter
70
Potential PROS
• Continuous backwash and sand
regeneration
• 30% less chemical than other
technologies
• Hydrous ferric oxide return
• Small footprint
Potential CONS
• Higher headloss than
settling alternatives
Fe3+
final
effluent
secondary
effluent
mixer Continuous
backwash
sand filter
reject
Fe3+
mixer
reject
Continuous
backwash
sand filter
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
adapted from Benish et al. (2007)
71. DynaSand® D2: co-precipitation + sand filter
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71
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Similar pros and cons as Blue PRO®
Al3+
final
effluent
secondary
effluent
mixer
DynaSand
Deep Bed
DynaSand
Standard
Bed
reject
AL3+
mixer
adapted from Benish et al. (2007)
72. Full-scale examples with chemically
enhanced two-stage filters
Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Facility
Capacity
(mgd)
Technology
Average
Effluent TP
(mg/L)
Hayden Regional WWTP
(Hayden, ID)
0.25 Ferric, Blue PRO 0.009 – 0.036
Stamford WWTP
(Stamford, NY)
0.5
Poly-aluminum-silicate-
sulfate (PASS), DynaSand D2
0.005 – 0.06
Walton WWTP
(Walton, NY)
1.55 PACl, DynaSand D2 0.005 – 0.06
Manotick WWTP
(Ontario, Canada)
0.04 DynaSand D2 <0.03
October 19, 2016
72
From USEPA (2007) Advanced Wastewater Treatment to Achieve Low Concentration of Phosphorus, EPA
910-R-07-002 and Schauer, P. and deBarbadillo, C. (2009) Pushing the Envelope with Low Phosphorus
Limits, PNCWA
73. DynaSand® D2 dual sand filtrationActiflo® + sand filters
ZeeweedTM tertiary ultrafiltration
membranes
Side-by-side piloting at Lakeshore WPCP
(Innisfil, Ontario)
Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Blue PRO® dual reactive sand
filtration
October 19, 2016
73
74. Ultra low P effluent from all technologies
during steady-state and diurnal phases
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74
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Similar results from comparative piloting including
Westborough, MA (Hart et al., 2009); Coeur d’Alene, ID
(Benisch et al. ,2007); Spokane, WA (Esvelt et al., 2010)
From deBarbadillo et al. (2009) Lakeshore Water Pollution Control Plant
Phosphorus Removal Pilot Testing
75. Tertiary P removal strategies
October 19, 2016
75
Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Also dissolved air flotation (DAF), algal-based
systems, low-pressure membrane filters (MBR
or tertiary) and reverse osmosis alternatives
A
Chemically
Enhanced
Clarification
and Polishing
Filters
B
Chemically
Enhanced
Two-Stage
Filters
C
Filtration and
Adsorption
Media with P
Recovery
C
Filtration and
Adsorption
Media with P
Recovery
76. • Granulated ferric oxides
• Activated aluminum oxides
• New polymeric metal oxide
• High selectivity for phosphate over competing anions
PO4
3- >> F- > SO4
2- > Br- , Cl-, NO2
- , NO3
-
• High breakthrough capacity even at high flow rate
• Repeatable adsorption/desorption cycle
Adsorption media alternatives
October 19, 2016
76
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Average diameter 0.55 mm
True density of raw material 28 lbs/gal
Bulk density of beads 2.9 lbs/gal
Porosity 85%
Adsorption capacity 15 g-P/L-R
Resistance to acid & alkali pH 2 to 14
77. Removal and recovery process
In situ media regeneration. Phosphorus recovery.
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Secondary
Effluent Filter Treated
Water
Solid/liquid
separation
pH
Control
Tank
A C
Precipitation
Reactor
Desorption
Tank
Lime
Tank
B
Acid
Tank
Caustic
Tank
Adsorption
Towers
Adsorption
Desorption
Recovery
Neutralization
Carrousel Operation
Two columns in series
Third columnstand-by
Waste
Phosphorus-Laden
Solids
77
78. U.S. pilot confirmed long-term piloting in
Japan
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percentage of measurements at or below value
(Phase 1A, 1B, 2, & 3)
FinalEffluentPSpecies(mg/L)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
FinalEffluentTSS(mg/L)and
Turbidity(NTU)
OP (Hourly Online Data)
OP (Daily Composite Lab Data)
TP (Daily Composite Lab Data)
Dissolved TP (Grab)
Soluble Non-reactive P (Grab)
Turbidity (Daily Composite)
TSS (Daily Composite)
78
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
From Fitzpatrick et al. (2010) First U.S. Pilot of a New Media for Phosphorus
Removal and Recovery, WEFTEC
79. Status of adsorption technology
• Polymeric metal oxide media
developed by Asahi
• In-situ regeneration with NaOH
• Long-term pilots successful in
U.S. and Japan
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Cross sectionExterior Surface Internal Structure
Fibril
Cavities
Cross sectionExterior Surface Internal Structure
Fibril
Cavities
ExteriorSurface Cross Section Internal Structure
• 0.13-mgd demonstration at Kasumigaura Lake WWTP
(near Tokyo) averaged TP < 0.03 mg/L during first year
• 10-mgd facility designed, pending ultralow permit limits 79
80. Concept for ultra-low P and recovery
without Fe, Al or Ca salts
October 19, 2016Fitzpatrick & Barnard | More Affordable, Reliable and Recoverable Nutrient Removal |
Slud
ge
Anaerobic
Digestion
Dewatering
Centrifuge
Biosolids
Primary Clarifiers Activated Sludge EBPR
Thickening
Centrifuge
Fermenter
& Thickener
Struvite Fertilizer
VFA Effluent Filter
Anaerobic
Release
Tank
Struvite
Reactor
Mg2+
(PO4)3-
Mg2+
K+
NH4
+
Phosphorus
Adsorption
Media
Desorption
Fluid
(PO4)3-, OH-
OH-
WASSTRIP®
and Struvite
Recovery
ASAHI
H+
MgNH4(PO4)·6H2O 80
K+
10% (PO4)3-
80% (NH4)+
81. BNR design must account for nutrients from
biosolids dewatering
October 19, 2016
81
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Anaerobic
Digestion
Dewatering
Biosolids
Primary Clarifiers Anaerobic | Oxic
Thickening
Particulate P
Chemical Precipitation
WAS
with
PAOs
(PO4)3-, Mg2+, K+, NH4
+
Particulate N & P
N & P in cells
NH4
+
(PO4)3-, Mg2+, K+
Secondary Clarifiers
Typical Range (not TBEL)
NH3-N = 0.1 to 2 mg/L
TP = 0.5 to 1.5 mg/L
82. Wet-weather flows = entirely different
environmental conditions
Opposite ends of the permitting spectrum
82
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0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
22,000
20 30 40 50 60 70 80 90 100
MaumeeRiverFlowRate(cfs)
WPCP Daily Average Flow Rate (mgd)
8/2/2007 - 7/31/2013 Flow Data
Maumee @ Coliseum Blvd Maumee @ Anthony Blvd 36 cfs
Existing permit used
36 cfs as Q7,10 for
low-flow WQBELs
Existingpermitaverage
design=60mgd
Existingpermitpeak
design=70mgd
Future Permit Conditions
Design Average = 74 mgd
Design Peak = 85 to 100 mgd
Fort Wayne, Indiana (8/2/2007 - 7/31/2013)
83. Clarification alternatives
October 19, 2016
83
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Settling-Based Filtration-Based Flotation-Based
1. Conventional Settling
-Rectangular, Circular, Square, RTB, Shaft
1. Shallow Granular Media 1. Conventional
Floatables Removal
-Skimmers, Scum baffles2. Vortex (Swirl Concentrator) 2. Deep Granular Media
3. Lamella Settler 3. Microscreens, Woven Media
-Salsnes Filter, Eco MAT™ Filter
2. Dissolved Air Flotation
(DAF)
4. Chemically Enhanced Settling
4. Floating Media
-MetaWater HRFS, BKT BBF-F
a. Conventional Basin
b. Sequencing Batch
- e.g. ClearCove Harvester™
c. Lamella Settler 5. Pile Cloth Media
-Aqua-Aerobic Systems 3. Polymer-aided DAF
-Various suppliersd. Solids Contact / Recirculation
- e.g. DensaDeg®, CONTRAFAST®
6. Compressible Media
-Fuzzy Filter™, WWETCO FlexFilter™
e. Ballasted Flocculation
- Microsand (e.g. ACTIFLO®, RapiSand™)
- Magnetite (e.g CoMag™)
7. Fixed-Film Contact
-Biological Aerated Filter (BAF),
BioFlexFilter™
4. Biocontact + DAF
-Captivator®
5. Suspended Growth Contact
-BIOACTIFLO™, BioMag™, Bio-CES
Enhanced RemovalSmall Footprint (High-Rate Treatment)Primary Removal Equivalent *
* If coagulation/flocculation provided, HRT EHRT (in some cases)
84. • Generally not. Stick closely to 40 CFR 133 definition:
• Monthly average. Across entire POTW.
• 001, A01, B01 approach is reasonable for blending or auxiliary treatment.
• 85% metric not appropriate for separate peak flow discharge.
Is 85% removal reasonable
during peak flows?
October 19, 2016
84
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0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Event 1 Event 2 Event 3
RemovalthroughActivated
SludgeProcess
Bay View WRP - Toledo, Ohio
Peak Flow Pathogen Removal Study (2011-Present)
Total Suspended Solids (TSS) Bichemical Oxygen Demand, 5-day (BOD5)
Nelson WWTP - Johnson County, Kansas
Wet Weather Flow Study (2003-2008)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 20 40 60 80 100 120 140
NelsonWWTPBODRemoval,%
Nelson WWTPCollection System Flow Rate, mgd
NormalConditions
PeakWet WeatherFlows
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0100200300400500600700800900
NelsonWWTPBODRemoval,%
Nelson WWTPInfluent BOD, mg/L
NormalConditions
PeakWet WeatherFlows
85. Are we focused on the right problem?
CDC 2009-2010 report ~50% of outbreaks in
U.S. surface waters were associated with
cyanobacteria toxins…not pathogens
October 19, 2016
85
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http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6301a2.htm#fig1
Only 22% (296 of
1326 cases) were
untreated venues
86. Longer term average limits and flow-tiered WQBEL
offer compliance remedies.
Expect short-term higher effluent levels
during peak wet-weather flows
86
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GPS-X Model Predictions for Wet-Weather Evaluation
P.L. Brunner WPCP (Fort Wayne, Indiana)
MonthlyNH3–N Limit
1.8 mg/l
DailyNH3–N Limit
4.2 mg/l
Overly
Stringent?
87. • Flow-tiered WLA and WQBEL.
• Determine receiving stream flow rate and mixing zone
above which there is no reasonable potential to exceed
facility’s wasteload allocation (WLA).
• Average weekly limits. Different statistics than
MDL. Ohio, Missouri and others.
• WLA based on dynamic water quality model instead
of steady-state.
• More accurately reflects actual environmental fate and
transport.
• More widely available and accepted now than when
recommended by USEPA guidance (1991).
Potentially better alternatives to overly
stringent maximum daily limits
October 19, 2016
87
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88. Standard approach may lead to
overly stringent MDL based on
chronic instead of acute
Scrutinize WQBEL
derivation procedures
October 19, 2016
88
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Source: Technical Support Document for Water Quality-
based Toxics Control, EPA/505/2-90-001, March 1991
89. State-of-the-art guidance includes:
October 19, 2016
89
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Sustainable solutions require site-specific plans,
design and management