recommendations and lessons learned from the startup of ......recommendations and lessons learned...
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Recommendations and Lessons Learned from the Startup of the First Two Full-Scale
Sidestream Deammonification Processes in North America: DEMON and ANITA Mox
Andrea Nifong, World Water Works (formerly HRSD)
Stephanie Klaus, VT & HRSD
Key Points
• Training is key but only 2 “champions” need in depth training
• Control strategy for long term operation is stable and hands off
• AOB are the most sensitive bacteria in the process, AOB are limiting not anammox
• 25°C is a reasonable minimum temperature
• Long term shutdowns are possible
2
Sidestream Deammonification
Influent Primary Clarifier
Aerobic Secondary Clarifier Tertiary
Anaerobic Digestor DewateringDeammonification
Primary Clarifier
Secondary Clarifier Tertiary
Anaerobic Digestor Dewatering
Centrate
• ~1% of Total Plant Influent Flow• ~20-40% of the Total Plant TN load• NH4 Concentration between 900 – 1,500 mg/L• Alkalinity/NH4 ratio ≅ 3.5-4.0• Temperature 30 - 38C• Alkalinity insufficient for complete nitrification• Insufficient carbon for denitrification
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Conventional Nitrification-Denitrification
NITRIFICATION
1 mol Ammonia
(NH3/ NH4 +)
1 mol Nitrite(NO2
- )
1 mol Nitrate(NO3
- )
75% O2 (energy)~100% Alkalinity
Autotrophic Bacteria
Aerobic Environment
1 mol Nitrite(NO2
- )
½ mol Nitrogen Gas(N2 )
25% O2 (energy)
40% Carbon (BOD)
60% Carbon (BOD)
Heterotrophic BacteriaAnoxic Environment
DENITRIFICATION
Nitritation
Nitratation
Denitritation
Denitratation
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Partial Nitritation + Anammox = Deammonification
1 mol Ammonia
(NH3/ NH4 +)
0.5 mol Nitrite(NO2
- )
37% O2 (energy)~57% Alkalinity
Autotrophic BacteriaAerobic Environment
½ mol Nitrogen Gas (N2 ) + 0.11 mol Nitrate (NO3-)
Autotrophic Anoxic Environment
NH4+ + 1.32 NO2
- + 0.066 HCO3- + 0.13 H+
0.26 NO3- + 1.02N2 + 0.066 CH2O0.5N0.15 + 2.03 H2O
Advantages: • 63% reduction in oxygen demand (energy) • Nearly 100% reduction in carbon demand • 80% reduction in biomass production • No additional alkalinity required
5
One-Step Sidestream Deammonification(with full-scale applications)
• Upflow Granular Sludge– Paques ANAMMOX®
• SBR– DEMON®
• MBBR – ANITA™Mox
– Deammon®
6
Operation Objectives
Target is 90% NH4 Removal
(80% TIN Removal)
• Typical Guidelines:o Residual alkalinity 150 -250 mg/L as CaCO3
o Residual NH4 of 50-100 mg/Lo Nitrite concentration below 20-40 mg/L
Target is 10-15% NO3 Production
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DEMON at York River
DEMON
DENITE FILTERS
HEADWORKS
AERATIONBASINS
ANAEROBIC DIGESTION
THICKENING
DEWATERING
Demon® York River WWTP
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1010
Seed Sludge Aeration System
Instruments & Controls
Tank
Blowers Decanter Mixer Cyclone
DEMON® Process Components
DEMON® – Control Strategy• SBR configuration – typically 6 or 8 hour cycle time• Last hour of cycle - settle and decant• During React Period – multiple mini-cycles (10-30 mins):
• Aerate• Mix/fill• Mix
• Aeration:• DO ~0.2-0.5 mg/L (PID control or constant airflow)• pH based aeration control
11
DEMON® Control Strategy - Anammox Enrichment
• Continual enrichment of anammox
– Large excess of activity
– Provides stability
• Ability to Washout NOB if proliferation occurs
Anammox returned to Process
AOB/NOB/OHO/debris
12
Seed Sludge
13
Confidential; Copyright 2013, World Water Works, Inc. All rights reserved.
13
NH4 and TIN Removal Percentages
0
10
20
30
40
50
60
70
80
90
100
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
8-Oct-12 28-Oct-12 17-Nov-12 7-Dec-12 27-Dec-12 16-Jan-13 5-Feb-13 25-Feb-13
NO
2-N
Co
nce
ntr
atio
n (
mg
/L);
Tem
pe
ratu
re (◦C
)
% N
H4
-N R
em
ova
l ; %
NO
3-N
Pro
du
ctio
n
NH4-N Removal NO3-N Production
NO2-N Cencentration Temperature
removal efficiency loss
due to low temperatures
14
NH4 Loading and Removal Rates
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
NH
4-N
kgN
/m3
/day
)
NH4-N Influent Load (kgN/m3/day)
NH4-N Load Removed (kgN/m3/day)
System Shut- down
15
HRSD James River Treatment Plant
16
ANITA Mox Process Components
Aeration System Instrumentation Centrate Feed
Mixers and Heaters K5 Media Media Retention17
Supplemental Heating
• DEMON
– Temp maintained above 25°C after supplemental heating was supplied
– Lesson Learned: Insulate or provide heating during startup
• ANITA Mox
– Temp maintained above 30°C during startup and 25°C long term
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Anitamox Process Control
• Centrate Feed Control
• Aeration Control
– Continuous and Intermittent
– Three Different Modes
1. Airflow setpoint (scfm)
2. Fixed DO setpoint
3. pH-based DO or airflow
• Mixer Control
19
Seeding and Startup
20
Biofilm Growth
Seed media
2/26/14
New media
4/10/14
Seed media
4/10/14
New media
2/26/14New media
7/15/14
Seed media
7/15/14
Seed media
12/12/13
New media
12/12/13
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0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
12/3/13 1/2/14 2/1/14 3/3/14 4/2/14 5/2/14 6/1/14 7/1/14
%, m
g/L
, C°
TIN Removal %
NH4 Removal %
NO2 out (mg/L)
Temperature
NO3 Production Ratio
StartupComplete
NH4 and TIN Removal Percentages
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NH4 Loading and Removal Rates
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
12/3/13 1/2/14 2/1/14 3/3/14 4/2/14 5/2/14 6/1/14 7/1/14
kg/m
3/d
ay
NH4 Load (kg/m3/day)
NH4 Removed (kg/m3/day)
IntermittentAeration
ContinuousAeration
Startup Complete
23
pH-based Aeration Control
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DEMON pH-Based Aeration Control– Aeration time is based on a low pH setpoint
– Anoxic/Feed time based on a timer or high pH setpoint
25
Option 1: ANITA Mox Fixed DO or Airflow Setpoint
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Time (min)
0 200 400 600 800 1000 1200 1400
pH
6.4
6.5
6.6
6.7
6.8
6.9
7.0
DO
(m
g/L
), C
en
tra
te F
low
(m
3/h
r)
0
2
4
6
8
10
12
14
pH
DO
Centrate Flow
DO setpoint
Option 2: ANITA Mox pH-Based Aeration Control
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Day
420 430 440 450 460 470 480
DO
(m
g/L
), C
en
tra
te F
low
(m
3/h
r),
pH
0
5
10
15
20
NO
3 P
rodu
ctio
n %
, N
H4
Rem
ova
l %
0
20
40
60
80
100pH Feedback
Centrate Flow
pH Setpoint
DO Setpoint
NO3 Production %
NH4 Removal %
DEMON and ANITA Mox – Both use a form pH-Based Aeration Control
• Control modes:• DEMON – pH affects aeration time at controlled DO• ANITA Mox – pH affects DO concentration
• pH Probe – minimal maintenance/calibration• Use handheld/lab probe to verify
• Consistent ammonia load & removal = constant OUR• 1 or 2 Lead Operators trained on pH Based aeration control
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Alarms and Fail Safes• Low pH = air shut off
• High DO = air and centrate feed shut off
• Low Level = air and centrate feed shut off
• Centrate Feed Pump Low Flow/Fail = air shut off
• High Level = centrate feed shutoff
• High/Low Temperature = alarm
• Cyclone Pump Low Pressure= shut off
• Manual Mode Alarm = alarm
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Training
• Entire plant staff trained on basic understanding of process theory, process components, analysis requirements and controls
• Daily meetings during startup, tapering to weekly meeting. Participants included: Plant staff, R&D team, and vendor.
• 1-2 of the plant staff understand in depth theory, troubleshooting, and process control
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Sampling/Analysis
Sampling• Frequency: Daily during startup
tapering down to weekly• Parameters:
-On site: HACH test kit NH3, NO2, NO3
-Lab data: Alk, sCOD, TSS, OP• Training: 2 Lab Technicians
Convenient Sample Ports
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Sensor ManagementInstrument Calibration
FrequencyMaintenance Function
pH Quarterly Max WeeklyCleaning
Control
DO Annual Weekly Cleaning/Air Blast
Control
Conductivity Annual No issue Monitoring
Ammonia/Nitrate As needed compared to lab values
Air Blast Monitoring
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Specific Conductivity• Specific conductivity represents the measure of all
relevant ions
• For deammonification the most important are NH4
+, NO2-, NO3
-, HCO3-
• Great monitoring tool
33
Specific Conductivity- ANITA Mox
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Day
420 430 440 450 460 470
pH
5.4
5.6
5.8
6.0
6.2
6.4
6.6
6.8
7.0
7.2
Sp
ecific
Co
ndu
ctivity,
NH
4
60
80
100
120
140
160
180
200
220
240
pH
NH4
Specific Conductivity
Centrate Quality• Automate centrate diversion valves
• Eliminate sources of dilution water
• Sufficient EQ size and settling
• Temperature control if necessary
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Micronutrient Addition
Source: Grady, C., Daigger, G., Love, N., Filipe, C. (2011). Biological Wastewater Treatment, IWA Publishing. 36
Micronutrient Deficiency - DEMON®
0
5
10
15
20
25
30
35
40
45
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
26-Jan-13 15-Feb-13 7-Mar-13 27-Mar-13 16-Apr-13 6-May-13 26-May-13 15-Jun-13 5-Jul-13
NO
2-N
Co
nce
ntr
atio
n (
mg
/L);
Te
mp
era
ture
(◦
C)
% N
H4
-N R
em
ova
l ; %
NO
3-N
Pro
du
ctio
n
NH4-N Removal NO3-N Production NO2-N Cencentration Temperature
Micronutrient Addition
37
ANITA Mox Micronutrient Deficiency
38
0
2
4
6
8
10
12
14
0
10
20
30
40
50
60
70
80
90
100
9/26/2014 10/26/2014 11/25/2014 12/25/2014 1/24/2015
pH
Pe
rce
nt
%
NH4 Removal %
NO3 Production Ratio
pH
12% NO3 Production
Resume Micronutrient Addition
Shutdowns
• Shutdown for a week at a time with no significant change in operation strategy
• > 1 week requires a reduced load during startup
• AOB are the limiting factor
• Anammox are very robust (very slow decay rate)
• DEMON and ANITA Mox appear similar
– One month shutdown for DEMON = one month restart
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ANITA Mox Shutdown Test
FIN EFF FIN EFF FIN EFFTKN NOx T-N
4/5/2015 2.42 2.33 4.754/6/2015 3.72 2.8 6.524/7/2015 3.63 3.28 6.914/8/2015 2.87 3.3 6.174/9/2015
4/10/20154/11/20154/12/2015 4.36 3.13 7.494/13/2015 5.95 3.07 9.024/14/2015 5.82 3.5 9.324/15/2015 5.99 3.92 9.91
With sidestream treatment
Without sidestream treatment
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James River Main Plant Performance with and without ANITA Mox
Conclusions
• Complete ownership of the system starts with daily, then weekly performance discussions with two champions of the system
• Anammox are robust, all limiting issues have been caused by AOB
• pH control is simple and effective
• Sidestream deammonification is a proven technology
• Process is not plug & play, careful attention required during startup
• Thoughtful attention during normal operation; set point changes ~1-2X/week (assuming good EQ)
• Lessons learned from DEMON applied to ANITA Mox
41