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