Lucy Pugh, P.E., BCEE – AECOM, Grand Rapids
2010 MWEA Biosolids ConferenceGrand Rapids, MichiganMarch 17, 2010
Sustainable Approaches for SidestreamNutrient Removal and Recovery
g Sidestream Characteristics
g Innovative Treatment Optionsg Biological processes
g Bioaugmentation g Nitritation / Denitritationg De-ammonification
g Physical-Chemical processes
Presentation OverviewNutrient Management at Plants with Anaerobic Digestion
Influent Primary Settling Tank
Final Settling
Tank
Effluent
Sidestream
Primary Sludge WAS
Dewatering
Thickening
RAS
AnaerobicDigestion
Biosolids
Activated Sludge
Plant Recycle Streams with High Ammonium Concentrations
• 1% of Total Plant Influent Flow
• Rich in Nitrogen & Phosphorus
• Ammonium conc. 800 to 2,500 mg-N/L
• 15 to 40% of the Total Plant TN load
• Often returned in slugs – not equalized
• Temperature 30 - 38°C
• Alkalinity insufficient for complete nitrification
• Low rbCOD (rbCOD :TKN = 0.4 :1)
Sidestream to Head of Plant
Primary Settling Tank
Influent Final Settling
Tank
Effluent
Sidestream Recycle
Primary Sludge WAS
Dewatering
RAS
AnaerobicDigestion
Biosolids
Blending with Influent Wastewater or Primary Effluent
Conventional Treatment Options
Activated Sludge
Thickening
Sidestream to Activated
Sludge Process
Primary Settling Tank
Influent Final Settling
Tank
Effluent
Sidestream Recycle
Primary Sludge WAS
Dewatering
Activated Sludge
RAS
AnaerobicDigestion
Biosolids
Blended with RAS in Activated Sludge Process
Conventional Treatment Options
Sidestream to RAS
Thickening
• Operationally Reliable • Removes 20-40% of nitrogen load even
during main plant process upsets• Protect the main plant from process
upsets due to variability in sidestream quality
• Sidestream can enhance main plant process nitrification with Bio-Augmentation
• Cost Effective• Optimize treatment based on the unique
characteristics of sidestream recycle• Small Footprint facilities
• Sustainable• Nutrient Recovery (Ammonia &
Phosphorus) rather than removal
Advantages of Separate Sidestream Treatment
View of Sidestream Treatment From Europe
Graphic from Markus Grömping, Atemis, 2009“Treatment of sludge return liquors: Experiences from the operation of full-scale plants,” Norbert, J et al., 2006, WETEC’06, WEF, Alexandria, VA.
Sidestream Treatment Options
Biological Physical-Chemical
Ion-Exchange• ARP
Struvite Precipitation• MAP Process
Nitrification / Denitrification& Bio-augmentation
• With RAS & SRT Control• With RAS• Without RAS
Nitritation / Denitritation • Chemostat • SBR• Post Aerobic Digestion
Deammonification• Suspended Growth SBR• Attached Growth MBBR• Upflow Granular Process
Novel Sidestream Treatment Options
Ammonia Stripping• Steam• Hot Air• Vacuum Distillation
In-Nitri®,BAR, AT#3 & BABE Bioaugmentation• Incubate a population of nitrifiers and then deploy them to the mainstream activated
sludge (AS) system • Mainstream AS volume / SRT can be reduced because of the elevated nitrifier population
from this seeding processAe
robi
c
Anoxic
½ mol Nitrogen Gas(N2 )1 mol Ammonia
(NH3 / NH4 +)
1 mol Nitrite(NO2
- )
1 mol Nitrate(NO3
- )
1 mol Nitrite(NO2
- )
Nitrification / Denitrification
Nitritation / Denitritation
75% O2
25% O2
40% Carbon
60% Carbon
Oxygen demand 2 mole / mole = 4.57 g / g NH+4-N oxidized
Alkalinity demand 2 mole / mole = 7.14 g / g NH+4-N oxidized
Carbon demand = 2.86 (3 - 4.5) g CODs / g NO-3-N reduced
AnaerobicDigestion
Dewatering
Aeration Alkalinity
Final Clarifiers
Primary
RAS
Nitrifier Rich NOx laden MLSS
Methanol
Influent Effluent
• Sidestream treated in a small separate tank (~4 day HRT)
• Portion of the mainstream RAS to sidestream tank Seeds nitrifiers, adds alkalinity & controls temperatureIntroduces Nitrite oxidizing bacteria
• Can add methanol for denitrification and methanol degrader seeding
AT#3• No dedicated clarifier
or RAS system• MLSS back to the
main AS process
BABE (Commercial)• SBR – built in clarifier• Control on SRT• WAS / Effluent back to the main
AS process• Clarifier effluent NOx to head of
plant for odor control (Phoenix)
• Several full scale installations - New York City (2), Hertogenbosch, NL. Extensive piloting and research.
AT#3 & BABE(Chemostat) (SBR)
Sidestream
BABE SBR
Sidestream
Clarified Effluent or Nitrifier Rich MLSS
Nitrifier Rich WAS
Sludge
Activated Sludge
AnaerobicDigestion
Dewatering
Nitrifier & denitrifier Rich MLSS
AT #3 Chemostat
Plant without Bio-Aug Integration
• Winter TN Removal Varied from 43% - 80% • Avg. 60%
Stinson et al., “ Evaluation and Optimization of a Side Stream Centrate Treatment System Integrated with a Secondary Step-Feed Process”, WEF / IWA Specialty Nutrient Conference, Baltimore 2007
Plant with Bio-Aug Integration
• Winter TN Removal Varied from 60% - 90% • Avg. 75%
Stinson et al., “ Evaluation and Optimization of a Side Stream Centrate Treatment System Integrated with a Secondary Step-Feed Process”, WEF / IWA Specialty Nutrient Conference, Baltimore 2007
26th Ward WPCP – 85 mgd
Operational Benefits
• “Nitrifier Incubator” enhanced operational reliability
• Enhanced winter performance• Mitigated storm washout impacts • Mitigated sidestream inhibition
• Mitigated air limitations• Off-Loaded 30% TKN Load • Oxidized 70-95% sidestream TKN• Denitrified in main plant anoxic zone using wastewater COD• >70% TN Removal Plant-Wide
Sidestream Treatment Options
Biological Physical-Chemical
Ion-Exchange• ARP
Struvite Precipitation• MAP Process
Nitrification / Denitrification& Bio-augmentation
• With RAS & SRT Control• With RAS• Without RAS
Nitritation / Denitritation • Chemostat • SBR• Post Aerobic Digestion
Deammonification• Suspended Growth SBR• Attached Growth MBBR• Upflow Granular Process
Novel Sidestream Treatment Options
Ammonia Stripping• Steam• Hot Air• Vacuum Distillation
Nitritation / denitritation (simplified)
1 mol Ammonia(NH3/ NH4
+)
1 mol Nitrite(NO2
- )
1 mol Nitrate(NO3
- )
Amm
onia
Oxi
dize
rs
(e.g
. Nitr
osom
onas)
75% O2
Nitri
te O
xidize
rs
(e.g
. Nitr
obac
ter
1 mol Nitrite(NO2
- )
½ mol Nitrogen Gas(N2 )
25% O2
40% Carbon
60% Carbon
1 mol Ammonia(NH3/ NH4
+)
1 mol Nitrite(NO2
- )
1 mol Nitrate(NO3
- )
Amm
onia
Oxi
dize
rs
(e.g
. Nitr
osom
onas)
75% O2
)
AutotrophicAerobic Environment
1 mol Nitrite(NO2
- )
½ mol Nitrogen Gas(N2 )
25% O2
40% Carbon
60% Carbon
HeterotrophicAnoxic Environment
Advantages;• 25% Reduction in Oxygen Demand• 40% Reduction in Carbon (e- donor) Demand• 40% Reduced Biomass Production
Short Circuit Conventional Process
Short-Circuited Nitrification/Denitrification Pathway
25% Reduction in Oxygen Demand 40% Reduction in Carbon Demand 40% Reduced Biomass Production
NitriteAmmonia
75% Oxygen 25% Oxygen
Nitrate
40% Carbon
Nitrite Nitrogen Gas
60% Carbon
• Temperature (30-38°C) favors growth kinetics of Ammonia Oxidizers
• SRT = HRT Sludge Age
>Minimum for Ammonia Oxidizers, but < Minimum for Nitrite Oxidizers
Selects for Ammonia Oxidizers (AOBs) & De-selects for Nitrite oxidizers (NOBs)
• pH in 6.6 to 7.2 range– Optimal range for AOBs
– Methanol for denitrification & alkalinity recovery
• DO in the 0.3 to 2 mg/l range
Nitritation / Denitritation Process Control
35˚C
Min AOB SRTNitrite Route
Courtesy: Grontmij
• Small Footprint– 2.5 day SRT = HRT
• Oxic SRT = 1 - 1.5 days• Anoxic SRT = 0.5 - 0.75 days
– No clarifiers– No pre-treatment
• 90% NH3-N removal
• Cost Reductions – 25% Oxygen demand– 40% COD demand– 40% sludge– 20% CO2 emission
SHARON Process (Chemostat)Stable and High activity Ammonia Removal Over Nitrite
Courtesy: Grontmij
SHARON Experience
WWTP Capacity(pe)
SHARONkgN/day
Operational
Utrecht 400.000 900 1997
Rotterdam-Dokhaven 470.000 850 1999
Zwolle 200.000 410 2003
Beverwijk 320.000 1,200 2003
Groningen-Garmerwolde 300.000 2,400 2005
The Hague - Houtrust 430.000 1,300 2005
New York-Wards Island ∼2,000,000 5,770 2009
Whitlingham, UK 275.000 1,500 2009
MVPC Shell Green, UK - 1,600 2009
Geneva – Aïre 2 600.000 1,900 2010
Paris Seine Grésillons 3,500 2010
• 7 operational >10 years experience• 4 planned• NYC DEP Wards Island
– First in USA & largest in world≈ 30 - 40% TKN-load
Chemostat Tank Configurations - SHARON Process Stable and High activity Ammonia Removal Over Nitrite
• Completely mixed tank with cyclical aeration – pH controlled
• Plug flow with internal recycle– Accommodates modifications for ANAMMOX process in the future
• Concentric circles – feed the anoxic zone to utilize all CODs in sidestream firstPump station Methanol
Heat exchangers
Phosphoric acid
Aerobic
Anoxic
Cooling water(treated effluent)
Effluent
Pump station
Methanol
10Q
Pump station
ANAMMOX½ Q
½ Q
Nitritation
WWTP Salzburg
Nitritation / Denitritation SBR ExperienceSTRASS Process
WWTP Strass
Sidestream Treatment Options
Biological Physical-Chemical
Ion-Exchange• ARP
Struvite Precipitation• MAP Process
Nitrification / Denitrification& Bio-augmentation
• With RAS & SRT Control• With RAS• Without RAS
Nitritation / Denitritation • Chemostat • SBR• Post Aerobic Digestion
Deammonification• Suspended Growth SBR• Attached Growth MBBR• Upflow Granular Process
Novel Sidestream Treatment Options
Ammonia Stripping• Steam• Hot Air• Vacuum Distillation
1 mol Ammonia(NH3/ NH4
+)
1 mol Nitrite(NO2
- )
1 mol Nitrate(NO3
- )
Amm
onia
Oxi
dize
rs
(e.g
. Nitr
osom
onas
)
75% O2
Nitri
te O
xidize
rs
(e.g
. Nitr
obac
ter)
AutotrophicAerobic Environment
1 mol Nitrite(NO2
- )
½ mol Nitrogen Gas(N2 )
25% O2
40% Carbon
60% Carbon
HeterotrophicAnoxic Environment
1 mol Ammonia(NH3/ NH4
+)
1 mol Nitrite(NO2
- )
1 mol Nitrate(NO3
- )
Amm
onia
Oxi
dize
rs
(e.g
. Nitr
osom
onas
)
75% O2
Nitri
te O
xidize
rs
(e.g
. Nitr
obac
ter)
AutotrophicAerobic Environment
1 mol Nitrite(NO2
- )
½ mol Nitrogen Gas(N2 )
25% O2
40% Carbon
60% Carbon
HeterotrophicAnoxic Environment
Deammonification (simplified)
AutotrophicAnaerobic
Environment
Benefits:• 63% reduction in oxygen demand• Almost 100% reduction in carbon demand• Significantly reduced biomass production• Reduced CO2 emissions (4.7 - 0.7 ton CO2/ton N)
Deammonification
• Low Growth Rate – 10 day doubling time at 20°C– SRT (30 - 50 days)
• Sensitive to:– Nitrite
• causes irreversible loss of activity • toxicity based on concentration &
exposure time • NH4
+ : NO2- ratio 1 : 1.32
1 Gallon 80 Gallons 635 Gallons 132,000 Gallons
– DO - reversible inhibition– Free ammonia (<10 mg/l)– Temperature >30°C preferred– pH (neutral range)
Bernhard Wett, 2005
Deammonification Configurations
Tank Configurations
• SBR-Type Process - DEMON®– 6 operational facilities
• Attached growth MBBR process– Hattingen, Germany– Stockholm, Sweden
• Upflow Granulation Process – 2 WWTPs
• Rotterdam • Niederglatt
– 5 industrial facilitiesUpflow Granulation
Process
DEMON® SBR
MBBR
• 84% TN Removal• 0.7 kg ammonia N per m3
• Reduced energy demand to 1.3 kW hr / kg N removed
DEMON® Sequencing Batch Reactor
Bernhard Wett, March 2009
• Plant undertook many energy efficiency activities • With the introduction of DEMON it became a net energy producer
DEMON® Sequencing Batch Reactor
Bernhard Wett, March 2007
Bernhard Wett, Water Science & Technology Vol 56 No 7, 2007
Nitritation / Denitritation• pH range 7.3 to 7.7• DO range 0.5 to 2.0 mg/l
Deammonification• pH range 7.06 to 7.07• DO range 0 to 0.3 mg/l
Comparison of Process Control requirements for Nitritation / Denitritation vs. Deammonification
MBBR Attached Growth Deammonification
Hattingen, Germany & Stockholm, Sweden
• Fully Autotrophic ANAMMOX-like Reaction
• Biomass Exists on Media for Stability– 40% K1 media fill– Less sensitive to nitrite concentration– Completely mixed tanks with
Intermittent aeration low DO
• >70% ammonium removal
• Energy consumption ~ 4.5 kW-hr/kg-N vs. 1.16 kW-hr/kg-N in STRASS SBR
TN load In
TN load Removed
Norbert, J et al., 2006, “Treatment of sludge return liquors: Experiences from the operation of full-scale plants,”WETEC’06, WEF, Alexandria, VA., p 5237-5255.
Upflow Granulation Process: ANAMMOX
• 2 WWTPs - Rotterdam, Niederglatt
• 5 Industrial Facilities
• Rotterdam ANAMMOX startup 2002
• Initially designed as a two-step process– SHARON - 1800 m3
– ANAMMOX – 72 m3
• TN removal > 90%
• Effluent NO2-N < 10 mg/l
Van der Star, W. R. L. et al., 2007, “Startup of Reactors for Anoxic Ammonium Oxidation: Experiences from the First Full-scale Anammox Reactor in Rotterdam.” Water Research, (41), 4149-4163.
NH4+
NO2-
• Granular biomass beneficial– low sensitivity to inhibition e.g. nitrite > 30
mg/l– Concentrated & compact - 17 times reduction
in volume vs. conventional– Granulation strongly dependent on upflow
velocity
• Next generation design: Single Stage Attached Growth Process – Olburgen, NL, Potato Processing Facility
3 years operation (startup 2006)
“Upgrading of sewage treatment plant by sustainable & cost effective separate treatment of industrial wastewater” IWA Krakow 2009, W.R. Abma, W. Driessen, R. Haarhuis, M.C.M van Loosdrecht
Inf NH4
Eff NH4 Eff NO3Eff NO2
Upflow Granulation Process: ANAMMOX
Sidestream Treatment Options
Biological Physical-Chemical
Ion-Exchange• ARP
Struvite Precipitation• MAP Process
Nitrification / Denitrification& Bio-augmentation
• With RAS & SRT Control• With RAS• Without RAS
Nitritation / Denitritation • Chemostat • SBR• Post Aerobic Digestion
Deammonification• Suspended Growth SBR• Attached Growth MBBR• Upflow Granular Process
Novel Sidestream Treatment Options
Ammonia Stripping• Steam• Hot Air• Vacuum Distillation
Enhanced Nutrient Recovery
• Recover and beneficially reuse both nitrogen & phosphorus– Finite amount of quality phosphorus resources available
• Several emerging technologies – Air or steam stripping– CAST vacuum distillation – Struvite precipitation
• Sell nutrient rich products as fertilizers
Ostara – Controlled Struvite Precipitation
Recovers P & N as Crystal Green®
Mg2+ + NH4+ + PO4
3- MgNH4PO4.6H2O
• slow release fertilizer
• produced without GHG emissions
Typical performance;
• 75% P recovery & 15% N recovery
• Reduced VFA demand in Bio-P plants
• Reduced aeration & alkalinity for NH4-N removal
• Edmonton (Goldbar plant) - 85 MGD Bio-P
• Durham, Oregon – 20 mgd effluent TP < 0.07 mg/l
• York PA & Hampton Roads Sanitation Authority, VA
Physical-Chemical Ammonia Recovery
Air Stripper Ammonia Recovery • 8 air strippers & 1 steam stripper operational in
Europe • VEAS 75 MGD plant • Operational >10 yrs• In operation 99% of time.
– Stop to wash tower, max 7 hours, 6 times a year• Ammonium Nitrate Fertilizer Product
CAST Vacuum Ammonia Recovery • First full-scale installation in NYC 26th Ward
WWTP 2010 – 1 mgd• Vacuum reduces NH3-N to < 200 mg/l• Ion exchange can recover the remaining NH3-N
CAST Concept
VEAS Air Stripper, Norway
Questions
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