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MAINSTREAM DEAMMONIFICATIONMark W. Miller
2015 VWEA Education Seminar
April 30th, 2015
Charles Bott HRSD, Sudhir Murthy DC Water, Bernhard Wett ARA Consult GmbH
Outline
• Conventional BNR to Mainstream Deammonification
• Mainstream Deammonification Strategies– Anammox Retention– Maximize AOB Growth Rates– NOB Out-selection– AVN (Ammonia versus NOx-N) Control
• AIZ Demonstration Study• DC Water Pilot Study• HRSD Pilot Study• Ongoing Research
CONVENTIONAL BNR TO MAINSTREAM
DEAMMONIFICATION
1 mole Ammonia
(NH3 / NH4 +)
½ mole Nitrogen Gas
(N2 )
75% O2 (energy)
100% Alkalinity (caustic)
1 mole Nitrite
(NO2-)
Autotrophic Aerobic
Environment
Heterotrophic Anoxic
Environment
Ammonia Oxidizing Bacteria (AOB)
1 mole Nitrite
(NO2-)
60% Org C
25% O2 (energy)
1 mole Nitrate
(NO3-)
Nitrite Oxidizing Bacteria (NOB)
40% Org C
Nitrification/Denitrification (1.0)
Nitrite Shunt/SND (2.0)
1 mole Ammonia
(NH3 / NH4 +)
½ mole Nitrogen Gas
(N2 )
75% O2 (energy)
100% Alkalinity (caustic)
1 mole Nitrite
(NO2-)
Autotrophic Aerobic
Environment
Heterotrophic Anoxic
Environment
Ammonia Oxidizing Bacteria (AOB)
Potential Advantages:
• 25% reduction in oxygen demand (energy)
• 40% reduction in carbon demand
• 40% reduction in biomass production
1 mole Nitrite
(NO2-)
60% Org C
1 mole Ammonia
(NH3 / NH4 +)
½ mole Nitrogen Gas (N2 )
+ a little bit of nitrate
(NO3-)
0.5 mole Nitrite
(NO2-)
Autotrophic Aerobic
Environment
Autotrophic Anoxic
Environment
37% O2 (energy)
~50% AlkalinityAOB
Potential Advantages:
• 63% reduction in oxygen demand (energy)
• Nearly 100% reduction in carbon demand
• 80% reduction in biomass production
Deammonification (3.0)
Anaerobic Ammonia Oxidizing Bacteria = Anammox
Anammox Bacteria
Limitation of Mainstream Deammonification
100% NOB out-selection, which convert NO2-N to NO3-N, may not be possible under mainstream conditions
11% NO3-N production by anammox bacteria, therefore, theoretically only 89% N removal is possible
Heterotrophs can reduce NO3-N but if C/N is too high they will out-compete anammox for NO2-N
MAINSTREAM DEAMMONIFICATION
STRATEGIES
Managing Populations• Anammox Bacteria
– Selective retention in mainstream– Bioaugmentation from sidestream deammonification
• Maximize AOB Growth Rates– Maximize substrate (ammonia), electron acceptor (DO), and
inorganic carbon (alkalinity) availability– AOB bioaugmentation from sidestream deammonification– Minimize inhibition– Minimize OHO competition for DO and space
• NOB Out-Selection– Aggressive aerobic SRT management– Intermittent aeration with rapid transitions to anoxia– Maximize inhibition– Maximize substrate competition from OHO and anammox
bacteria
C/N Ratio is an Important Factor for N Removal Pathway
Conventional Nitrification/Denitrification
Nitrite Shunt Deammonification
High C/N
6-10/1 range ?
Heterotrophs Dominate
Medium C/N
3-5/1 range ?
Low C/N
1-3/1 range ?
Mostly Anammox
Carbon Removal Alternatives
• Primary Sedimentation– >10 C/N dependent on influent C/N
– 20-30% COD removal (no sCOD removal)
• A-stage (HRAS)– 3-10 C/N (SRT 0.5-0.1 days)
– 40-70% COD removal
• Chemically enhanced primary treatment (CEPT)– 3-6 C/N with coagulation/flocculant addition
– 50-80% COD removal (some sCOD removal)
• High-rate activated sludge (or chemically enhanced A-stage)– 1-2 C/N
– 70-90% COD removal
ANAMMOX RETENTION
Full-scale experiments at WWTP Glarnerland
Anammox enrichment in the Cyclone-underflow
Anammox enrichment in the Cyclone-underflow
MAXIMIZE AOB GROWTH RATES
Maintain Residual TAN > 1.5 mg/L• Ammonia levels and temperature are too low for NH3 (FA) inhibition
• High ammonia loading rates favor AOB growth rates
• Residual ammonia ensures AOB grow closer to their maximum growth rate at all times
0.0
0.2
0.4
0.6
0.8
1.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Sp
ecif
ic g
row
th r
ate
(1
/d
)
mg/L (AOB:NH4+-N, NOB:NO2
--N)
mu-AOB mu-NOB
Monod Curves for AOB and NOB
DO (mg/L)
0.0 0.5 1.0 1.5 2.0
Act
ivit
y (
mg
N/L
.d)
0
100
200
300
400
AOB rate
NOB rate
Monod model NOB fit
Monod model AOB fit
Monod Curves for AOB and NOB
Operate at DO > 1.5 mg/L
• High DO (>1.5 mg/L) allows AOB (r-strategist) to grow close to their maximum rate and out-select NOB (K-strategist)
MAINSTREAM NOB OUT-SELECTION
21
Intermittent Aeration with Rapid Transitions to Anoxia
• Competition for NOB substrate by OHO or anammox
• NOB lag induced by periods of anoxia
Aggressive SRT Control
• Operate the system at an SRT close to AOB washout
– Maximizes AOB rates
– Washout NOB if AOB rates > NOB rates
• Needs to be automated since operating with small SRT safety factor
• Can be based on aerobic fraction or in situAOB rates
AVN (AMMONIA VS NOX-N)
Residual Ammonia High DO Transient Anoxia Aerobic SRT control
D.O. D.O. D.O.NO2-NNO3-N
NH4-N
Aerobic Duration
Controller/PLC
DOController/
PLC
DO = set point
NOx-N/NH4-N = setpoint
D.O.
MAirS
Regmi, P., Miller, M. W., Holgate, B., Bunce, R., Park, H., Chandran, K., et al (2014). Control of aeration, aerobic SRT and CODinput for mainstream nitritation/denitritation. Water Research, 57, 162-171. Pérez, J., Lotti, T., Kleerebezem, R., Picioreanu, C., & Loosdrecht, M. C. M (2014). Outcompeting nitrite-oxidizing bacteria in single-stage nitrogen removal in sewage treatment plants: a model-based study, 1-50. doi:10.1016/j.watres.2014.08.028
AVN Aeration Control
AVN Aeration Control in Action
Aer
obic
Fra
ctio
n
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Nit
roge
n (m
g/L
)
0
2
4
6
8
10
Aerobic Fraction
NH4-N
NO2-N
NO3-N
NOx-N
24-hour
Dis
solv
ed O
xyge
n (m
g/L
)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
DO
1-hour
Dis
sove
d O
xyge
n (m
g/L
)
0.0
0.5
1.0
1.5
2.0
A
B
AIZ (ACHENTAL-INNTAL-ZILLERTAL) DEMONSTRATION STUDY AT THE STRASS
WWTP
Strass WWTP Demonstration Study
• Carousel type aeration tank at Strass provides a DO range of 0 to 1.7 mg/L along the flow-path
• Can be operated in parallel or in series
• Ammonia-based aeration control
• Future operation will include AVN aeration control
DO=1.4-1.5 mg/L 0.19 mg/L 0.35mg/L
0.010.09mg/L0.6mg/L 1.6-1.7mg/L
Full-scale experiments at WWTP Glarnerland
0
5
10
15
20
25
1-Dec 21-Dec 10-Jan 30-Jan 19-Feb 10-Mar 30-Mar 19-Apr 9-May 29-May
2010/2011 NO3-N effluent 2010/2011 NO2-N effluent 2011/2012 NO3-N effluent 2011/2012 NO2-N effluent
nit
roge
n c
on
cent
rati
on
(mg
N/L
)
0
10
20
30
40
50
60
1-Dec 21-Dec 10-Jan 30-Jan 19-Feb 10-Mar 30-Mar 19-Apr 9-May 29-May
2010/2011 NH4-N influent 2010/2011 NH4-N effluent 2011/2012 NH4-N influent 2011/2012 NH4-N effluent
nitr
ogen
con
cent
ratio
n (m
g N
/L)
• Typically experience high nitrate levels during Christmas peak load• Similar temperature (~10°C) , load, and ammonia effluent concentrations (2-5 mgN/L) for
both years
Comparison of Operational Data Indicating NOB Out-selection
N-removal Efficiency of the Strass WWTP
0
5
10
15
20
25
30
35
40
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
specific N-load [kgN/m3/d] total N_B [mg/l]
Effl
ue
nt
TN (
mg
/L)
Vo
lum
etri
c N
Lo
adin
g (k
gN/m
3/d
ay)
DC WATER PILOT STUDY AT THE BLUE PLAINS
ADVANCED WATER TREATMENT FACILITY
Primary Clarifiers
High-rate AS
reactors
Secondary Clarifiers
Nitrification Denitrification
AS reactorsNitrification Denitrification
Clarifiers
Final Dual-media Filters
Potomac River
Bar Screens and Grit
Chambers
Blue Plains AWTP
• 370 mgd (AA) to 518 mgd (Max Day)
• TN ~3-4 mg/L & TP < 0.18 mg/l
•12◦C winter monthly average
New Filtrate Treatment Process
Upgrade & expansion of the Nit/ Denit system
New Biosolids Management Program
High Rate Process
Rehabilitation
Enhanced Nutrient Removal
Facilities
Relevant CIP Projects at Blue Plains
The Road to Sustainable and Efficient Nitrogen Management
1. A-Stage – Maximize carbon capture
2. Biosolids – Maximize energy recovery
3. B-Stage – Minimize carbon & energy demand for N & P removal
1 3
3
2
Sequential Oxic/Anoxic Mainstream Pilot Study
Nitrogen Concentrations in Space
0
1
2
3
DO
(m
g/L)
0
1
2
3
4
5
6
7
8
9
10
1 2 3 4 5 6 7 8 9 10 11
Nit
roge
n c
on
cen
trat
ion
(mgN
/L)
Cell number in Pilot
NH4NO2NO3
-400
-300
-200
-100
0
100
200
300
400
cell 1 cell 2 cell 3 cell 4 cell 5 cell 6 cell 7 cell 8 cell 9 cell 10
Vo
lum
etr
ic r
em
ova
l rat
es
(mg
N/L
/d)
Nitrogen Volumetric Removal Rates
NH3 NO2
NO3 Ntot
HRSD PILOT STUDY AT THE CHESAPEAKE-ELIZABETH TREATMENT PLANT
Chesapeake-Elizabeth Treatment Plant
RawWastewater
ScreeningFeCl3
GritRemoval
High Rate Aeration Tanks
(SRT=1.5 to 2 days)
FeCl3
RAS
Chlorine Contact
Discharge to Chesapeake Bay
GravityThickener
WAS
Centrifuge
Multiple Hearth Incinerators
CH4
ASH
Parameter Value
Design Flow (MGD) 24
Operating Flow (MGD) 15-20
Annual TP Limit (mg P/L) 2
TN Limit (mg N/L) N/A
Adsorption/Bio-oxidation Process
40
RAS WAS
AERPCL ANX AER SCL
MLR
RAS
B-stage
WAS
A-stage
AER
PSL
MLE
Shortcut N RemovalNitrite Shunt
SNDDeammonification TN 15-18 mg/L
TN 10-12 mg/LTN < 5 mg/L
Advantages Disadvantages
Increased sludge production Chemical addition for P removal
Redirect carbon for energy recovery B-stage is C limited
Low aeration energy requirement A-stage lacks process control
Lower overall volume (or increased removal capacity)
HRSD CE BNR Pilot Study
RAS
Air
RAS WAS
RWI Influent
A-stage HRAS
Air
B-stage AVN Anammox MBBR
IMLR
Inf
WAS
NITRATE POLISHING
Anoxic Organisms
OHO
NO3-NO3-
NO2-
N2
sCOD
CO2
New Biomass
Anammox
NH4+
NO2-
N2
NO3-
Kartal, B., Kuypers, M.M.M., Lavik, G., Schalk, J., Op den Camp, H.J.M., Jetten, M.S.M., Strous, M. 2007. Anammox bacteria disguised as
denitrifiers: nitrate reduction to dinitrogen gas via nitrite and ammonium. Environmental Microbiology 9, 635-642.
Novel Anammox
NO3-
NO2-COD
(VFA)
CO2
No bio
mas
s fro
m
COD
Nitrate Removal with Limited COD Addition
Acetate (COD)
AVN effluent
NO2-N removed/NH4-N removed = 1.32(Anammox Stoichiometry)
COD added/Inf Nitrate ≈ 0.5-1
Ongoing Research
• Continued work on COD removal mechanisms and control strategies for CEPT, HRAS, A-stage, and high-rate CSAS
• Implementation of AVN controller at the Strass WWTP
• NO and N2O inhibition and NOB lag
• Impact of mainstream deammonification on GHG emissions
Collaborators
Recommended