kam law, p.e. beverley stinson, ph.d....•mitigated storm washout impacts •mitigated centrate...

Sidestream Treatment Overview

Kam Law, P.E.

Beverley Stinson, Ph.D.

March 20, 2012

Presentation Outline

• Concerns with sidestream

• Treatment options

• Treatment processes comparison

• Summary

Influent Primary

Settling Tank Final

Settling

Tank

Effluent

Centrate / Filtrate

Primary

Sludge WAS

Dewatering

Thickening

RAS

Anaerobic

Digestion

Biosolids

Activated

Sludge

• 1% of Total Plant Influent Flow

• Rich in Nitrogen & Phosphorus

• 15 to 40% of the Total Plant TN load

• 50% TP load

• Often returned in slug loads – not equalized

• Ammonium Conc. 800 to 2,500 mg-N/L

• Temperature 30 - 38C

• Alkalinity insufficient for complete

nitrification

• Poor in rbCOD (rbCOD :TKN = 0.4 :1)

Concerns with sidestream

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

Deammonification • Suspended Growth SBR • Attached Growth MBBR • Upflow Granular Process

Novel Sidestream Treatment Options

Ammonia Stripping • Steam • Hot Air • Vacuum Distillation

Nitrification / Denitrification & Bioaugmentation

½ mol Nitrogen Gas (N2 )

1 mol Ammonia

(NH3 / NH4 +)

1 mol Nitrite (NO2

- )

1 mol Nitrate (NO3

- )

1 mol Nitrite (NO2

- )

Nitrification / Denitrification

75% O2

25% O2

40% Carbon

60% Carbon

• 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 process

• AT#3 – with RAS

• BABE – BioAugmentation Batch Enhanced

Process

• In-Nitri® – without RAS

• BAR – BioAugmentation Reaeration/Regeneration

• RDN – Reaeration Nitrification Denitrification

• CaRRB – Centrate and RAS Reaeration Basin

Nitrification / Denitrification & Bioaugmentation

Anaerobic

Digestion

Dewatering

Aeration

Alkalinity

Final

Clarifiers

Primary

RAS

Methanol

Influent Effluent

• Centrate treated in a small separate tank (~4 day HRT)

• Portion of the mainstream RAS to centrate tank Seeds nitrifiers, adds alkalinity & controls temperature

Introduces Nitrite oxidizing bacteria

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)

• NOx denitrified in first anoxic zone of AS system

• Problematic in a Bio-P plant

• Can add methanol for denitrification and methanol degrader seeding

• Several full scale installations - New York City (2), Netherland.

Extensive piloting and research.

AT#3 & BABE (Chemostat) (SBR) (BioAugmentation Batch Enhancement)

Centrate

BABE SBR

Centrate

Clarified Effluent or

Nitrifier Rich MLSS

Nitrifier

Rich WAS

Sludge

Activated

Sludge

Anaerobic

Digestion

Dewatering

Nitrifier & denitrifier

Rich MLSS

AT #3 Chemostat

Primary Sludge

Thickening

Primary

Sedimentation

Tank

Raw

Wastewater Aeration

TankSecondary

Sedimentation

Tank

Treated

Effluent

WAS

Thickening

Digester

Sludge

Dewatering

Sludge for

Disposal

Dewatering

Return Stream

Supernatant

Thickened

Primary Sludge

Excess

Nitrification

SludgeNitrified

Dewatering

Liquid

Side-stream

Nitrification

Alkalinity

In-Nitri® BAR / RDN / CaRRB

• BioAugmentation Reaeration/Regeneration (BAR) • Reaeration Nitrification Denitrification (RDN) • Centrate and RAS Reaeration Basin (CaRRB)

• Centrate aerated in a separate side stream tank

with dedicated clarifier

• No main stream RAS

• Primary effluent can be added to enhance

settling & add alkalinity

• No full scale installations

• Bioaugmentation potential not verified

• Patented Process - Royalties

• Centrate aerated in first zone of AS tanks

• All main stream RAS added to centrate

reducing temperature & adding alkalinity

• PE directed to a downstream zone

• Many full scale installations

–Appleton, Czech Republic (20),

Inland Empire, Blue Lake, Denver

• Bioaugmentation potential observed

Dewatering

Final

Clarifiers

Primary

RAS

Influent Effluent

Centrate

Anaerobic

Digestion

Activated

Sludge

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 centrate inhibition impacts

• Mitigated air limitations

• Off-Loaded 30% TKN Load

• Oxidized 70-95% Centrate TKN

• Denitrified in main plant anoxic zone using

wastewater COD

• >70% TN Removal Plant-Wide

• Nitrite Accumulation in Main Plant Suggested

Selection of AOB over NOB

Key Design Consideration

• Oxygen Uptake Rate

– OUR (>150 mg/ l hr) can define the size of

tank

– Select diffuser to operate at temperatures >

30C and with intermittent aeration in an

SBR (clogging)

• Control RAS addition

– Provides alkalinity

– Develops an integrated culture of nitrifiers

– Cools centrate – temp. difference important

• Too great nitrifers may not remain

active in AS

• Too cool – loose selection for AOBs

over NOBs

– Don’t want to recycle too many Nitrite

Oxidizing Bacteria (NOBs)

• May need to provide Alkalinity & OP addition

Colder side

stream process

More NO3-N

Courtesy B.Wett

1 mol Ammonia

(NH3/ NH4 +)

1 mol Nitrite(NO2

- )

1 mol Nitrate(NO3

- )

Am

monia

Oxi

diz

ers

(e.g

. N

itro

som

onas

)

75% O2

Nitrite

Oxi

diz

ers

(e.g

. Nitro

bac

ter)

Autotrophic

Aerobic 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

- )

Am

monia

Oxi

diz

ers

(e.g

. N

itro

som

onas

)

75% O2

Nitrite

Oxi

diz

ers

(e.g

. Nitro

bac

ter)

Autotrophic

Aerobic Environment

1 mol Nitrite(NO2

- )


25% O2

40% Carbon

60% Carbon


Nitritation / denitritation (simplified)

• 25% Reduction in Oxygen Demand

• 40% Reduction in Carbon (e- donor) Demand

• 40% Reduced Biomass Production

1 mol Ammonia

(NH3/ NH4 +)

1 mol Nitrite (NO2

- )

1 mol Nitrate (NO3

- )

75% O2

Autotrophic

Aerobic Environment

1 mol Nitrite (NO2

- )

½ mol Nitrogen Gas (N2 )

25% O2

40% Carbon

60% Carbon

Heterotrophic Anoxic Environment

Nitritation / Denitritation

• SHARON Process – Stable and High activity

Ammonia Removal Over Nitrite

• Strass Process – batch system

Nitritaton / Denitritation

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 centrate first

Pump

station Methanol

Heat exchangers

Phosphoric acid

Aerobic

Anoxic

Cooling water

(treated effluent)

Effluent

Pump

station

Methanol

10Q

Pump

station

ANAMMOX ½ Q

½ Q

Nitritation

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

Courtesy: Grontmij

Chemostat Tank Configurations - SHARON Process Stable and High activity Ammonia Removal Over Nitrite

SHARON Experience/Installations

WWTP Capacity

(pe)

SHARON

kgN/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

• 6 operational >10 years experience

• 5 planned

• NYC DEP Wards Island

– First in USA & largest in world

30 - 40% TKN-load

SBR Tank Configuration - STRASS Process

• Control SRT and HRT independently

– Single unit process with clarification step

• Easy adjustment to the aerobic vs. anoxic cycles

– “Invent type” mixer / aerator provides both aeration & mixing

– no diffusers – avoids clogging / cleaning concerns

• Beneficial to fill only during anoxic cycles to utilize available carbon for denitrification & alkalinity recovery

• Split WAS and effluent flow streams

– WAS to activated sludge for seeding

– Effluent to activated sludge for TN polishing

– Effluent to head of plant for odor control using NO2-N

STRASS SBR Process Control Bernhard Wett, Water Science & Technology Vol 56 No 7, 2007

WWTP Salzburg

WWTP Strass

SBR Tank Configuration - STRASS Process

• Temperature (30-38C) 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

1 mol Ammonia

(NH3/ NH4 +)

1 mol Nitrite(NO2

- )

1 mol Nitrate(NO3

- )

Am

monia

Oxi

diz

ers

(e.g

. N

itro

som

onas

)

75% O2

Nitrite

Oxi

diz

ers

(e.g

. Nitro

bac

ter)

Autotrophic

Aerobic Environment

1 mol Nitrite(NO2

- )


25% O2

40% Carbon

60% Carbon


1 mol Ammonia

(NH3/ NH4 +)

1 mol Nitrite(NO2

- )

1 mol Nitrate(NO3

- )

Am

monia

Oxi

diz

ers

(e.g

. N

itro

som

onas

)

75% O2

Nitrite

Oxi

diz

ers

(e.g

. Nitro

bac

ter)

Autotrophic

Aerobic Environment

1 mol Nitrite(NO2

- )


25% O2

40% Carbon

60% Carbon


• 60% reduction in Oxygen demand • Almost 100% reduction in Carbon demand • Much reduced in Biomass production • Reduced CO2 emissions

Autotrophic

Anaerobic

Environment

Deammonification (simplified)

0.57

Partial Nitrification

40% O2

ANAMMOX

Anaerobic Ammonium Oxidation

Autotrophic Nitrite Reduction

(New Planctomycete, Strous et. al. 1999)

ANAMMOX Organisms

• Low Growth Rate – approx. 10 day doubling time at 30C

– <10 day has been reported (Park et. al - 5.3 - 8.9 days)

– SRT (>30 days)

• Sensitive to; – Nitrite

• Toxic- irreversible loss of activity based on concentration & exposure time

• NH4+ : NO2

- ratio 1 : 1.32

– DO - reversible inhibition

– Free ammonia (<10 -15 mg/l)

– Temperature >30C preferred

– pH (neutral range)

Keys to success

The Ability to Manage Competing Demands:

Manage SRT -

• Aerobic SRT - long enough to support AOB growth but short enough to washout NOBs (2<SRT<3) and

• Anaerobic SRT - long enough to support ANAMMOX growth (>30)

Manage DO –

• high enough to support partial nitritation

• But low enough to suppress NOB growth (Ks AOBs< Ks NOB)

• And also low enough so that it does not inhibit ANAMMOX (reversible)

Manage Nitrite Concentration –

• Sufficient nitrite to support ANAMMOX growth (electron acceptor)

• But low enough to avoid ANAMMOX inhibition (irreversible)

Manage Ammonium Concentration -

• Sufficient ammonium to serve as energy source for ANAMMOX

• But avoid free ammonia inhibition of AOBs (<15 mg/l)

Deammonification Process Configurations

• DEMON® Suspended Growth SBR process

– 12 operational facilities mainly in Europe (2011)

– Several under design in NA

• Attached growth MBBR process

– Hattingen, Germany (2000)

– Himmerfjärden, Sweden (2007)

– Sjölunda, Malmö, Sweden (ANITATM Mox pilot)

– Sundet WWTP Sweden (Dec 2011)

• Upflow granulation process

– ANAMMOX® by Paques

– 11 operational facilities (2011)

– More industrial than municipal ANAMMOX® Upflow

Granulation Process

DEMON® SBR

ANITATM Mox MBBR

DEMON® Suspended Growth SBR

• 84% TN Removal

• 0.7 kg ammonia N per m3

• Reduced energy demand to 1.3 kW hr / kg N removed

DEMON® SBR Process Control

DEMON® depends on 3 main controls

– pH (narrow range e.g. 7.01 – 7.02)

– DO (0 – 0.5 mg/L)

– Time

Provides accurate adjustment of all three key aspects

– free ammonia inhibition <10 mg/L)

– nitrite toxicity (<5 -10 mg/L)

– inorganic carbon limitation

Measure NH3-N, NO2-N, NO3-N and make process control decisions, primarily wasting, based on measurements

Attached Growth MBBR Concept

• Simultaneous aerobic and anaerobic conditions in biofilm layers

– NH3-N, alkalinity & DO in the bulk liquid

– AOBs on the outer aerobic layer

– ANAMMOX on the inner anaerobic layer

• ANAMMOX organisms in attached growth are

less sensitive to inhibitory compounds

– DO: 3 mg/L vs. 0.3 mg/L suspended

– NO2-N: 50 mg/L vs. 5 mg/L suspended

Courtesy Veolia

Upflow Granulation Process: ANAMMOX®

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-

• Most notable WWTPs:

– Rotterdam (NL), Niederglatt (CH)

• Numerous industrial facilities

• Rotterdam ANAMMOX startup 2002

• Initially designed as a two-step process

– SHARON – 1,800 m3

– ANAMMOX – 72 m3 (compact!)

• >2 yrs before ANAMMOX activity was detected

• >3.5 yrs to reach full capacity

• Removal rate 7.1 - 9.5 kg/m3/day

– Refers to second stage

• TN removal ~90%

• Effluent NO2-N < 10 mg/l

GHG emissions (as % of N removed)

DEMON® (Weissenbacher et al. 2010)

2-Stage

SHARON®-

ANAMMOX® (Kampschreur et. al. (2008)

1-Stage

ANAMMOX® (Kampshurer et al. 2009)

ANITATM Mox (Christensson et al. 2011)

NO2-N: <5 mg/L

DO: <0.3 mg/L

SHARON stage:

NO2-N: 500 mg/L

DO: 2.5 mg/L

ANAMMOX stage:

NO2-N: 3 mg/L

DO: unaerated

NO2-N: 6-8 mg/L

DO: 5 mg/L

NO2-N: < 5 mg/L

DO: 0.6 -1.6 mg/L

N2O: 1.5%

NOx: <0.1%

NO2 >10 mg/L resulted in

increase of N2O, stressing the

importance of managing

nitrite accumulation

N2O: 2.3%

(85% in Stage 1)

NO: 0.24%

(99% in Stage 1)

N2O: 1.7%

NO: 0.007%

N2O: 0.2 – 0.9%

NO: n/r

A study of 25 full scale WWTP show large variation, average N2O emission of 0.6% and

maximum emission of 14.6% (Wicht and Beier, 1995)

Comparative Summary of Deammonification

Processes

Suspended

SBR

(DEMON®)

Attached

MBBR

(ANITATM Mox)

Granular

Single-Stage

(AMAMMOX®)

Volumetric

Loading Rates kg N/m3/day 0.7 – 1.2 0.7 – 1.2 1.7 – 2.0

Performance

TN Removal %

~90% NH3-N

~85% TN

~90% NH3-N

~80% TN

~90% NH3-N

~75% TN

Energy Demand kW hrs/ kg

NH3-N

removed

1.0 – 1.3 1.45 – 1.75 N.R.

literature data suggests

higher*

Operator

Attention Highest Lowest Middle

Sensitivity /

Flexibility

pH & DO control;

NO2 < 5 mg/l

Pre-settling

DO control;

Tolerates

elevated NO2

DO control;

Tolerates

elevated NO2

GHG Emissions Low Lowest Low

*Kampshurer et al. 2009 report normal operations of 5 mg/L DO and 22% of NH3-N removed to NO3-N

In summary…

General guidelines for alternative biological

sidestream treatment options

Side stream

treatment option

Loading

rate

(kg NH3-N/m3)

SRT

(days)

HRT

(days)

Energy

demand (kWh/kg N)

Carbon

demand

(kg COD/kg

N)

Nitrification /

denitrification

Bioaugmentation

0.3 to 0.4 5 – 10 1.5 (Nit)

3 (Denit) 4 – 6.5 3 - 4

Nitritation /

denitritation 0.6 2 – 10 2 ¼ - 3 1.8 – 2.9 1.8 – 2.5

Deammonification 0.7 20-30 1 - 3 0.8 – 1.3

(4.5 Hattingen

MBBR)

0.1

Centrate / Filtrate Management Options

Nitrification / Denitrification & Bio-augmentation

Nitritation / Denitritation

Deammonification / ANAMMOX

Biological

Nitrogen

Removal

Focus

• Reduction in energy & chemical demands – more sustainable

• Perceived increase in operational complexity

Novel Sustainable Centrate/Filtrate Management

Options

Energy

Demand

Thank you.

Contact:

[email protected]

kam law, p.e. beverley stinson, ph.d....•mitigated storm washout impacts •mitigated centrate...

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