Kam Law, P.E. Beverley Stinson, Ph.D....•Mitigated storm washout impacts •Mitigated centrate...
Transcript of 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
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
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
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
- )
½ mol Nitrogen Gas(N2 )
25% O2
40% Carbon
60% Carbon
HeterotrophicAnoxic Environment
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
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
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
- )
½ mol Nitrogen Gas(N2 )
25% O2
40% Carbon
60% Carbon
HeterotrophicAnoxic Environment
• 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