Use of anammox systems to reduce nutrient concentrations Haydee De Clippeleir, PhD. Research Program manager DC Water
Use of anammox systems to reduce nutrient concentrations
Haydee De Clippeleir, PhD. Research Program manager
DC Water
outline
• Nutrient removal: 1.0 3.0 • Sidestream deammonification:
– Process level benefits – Global plant benefits – Technologies
• Mainstream deammonification: a new paradigm shift for the plant of the future
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% Alkalinity
AOB
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
Sidestream Deammonification
Influent Primary Clarifier
Aerobic
Secondary Clarifier Tertiary
Anaerobic Digestor Dewatering Deammonification
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 N/L • Alkalinity/NH4 ratio ≅ 3.5-4.0 • Temperature 30 - 38°C • Alkalinity insufficient for complete nitrification • Insufficient carbon for denitrification
7
What’s the benefit on process level?
• Remove ~20% of the N load to the plant by treating the centrate separately
• Do it with: – No chemicals (caustic & methanol) – < 40% of the energy cost – (as compared to traditional nitrification-denitrification)
• Business case is very good, particularly if existing tanks can be used
• Risks: – Requires robust process control, particularly during startup – Process has been adequately demonstrated – Seeding required for fast startup
8
What`s the benefit on plant level?
• Anammox technologies are they key to achieve energy autarky:
0
1
2
3
4
5
6
7
Nitrification / Denitrification
Nitritation / Denitritation
Deammonification(a.k.a. ANAMMOX)
kW-h
r / k
g N
rem
oved
Typical Energy Demand Ranges
anammox
Without anammox With anammox
-53 -27 Wh IE-1 d-1
One-Step systems • SBR + Hydrocyclone Granular Sludge
(DEMON) – Strass, Austria – Demon GmbH – World Water Works, Inc.
• Upflow Granular Sludge
(CANON/ANAMMOX) – Olburgen, Netherlands – Paques (NL)
• Biofilm process (MBBR-style)
– ANITA Mox – Malmo, Sweeden • AnoxKaldnes – Kruger - Veolia
– Deammon -- Hattingen, Germany & Stockholm • Purac
10
S-curve for anammox technology
Susanne Lackner, Eva M. Gilbert, Siegfried E. Vlaeminck, Adriano Joss, Harald Horn, Mark C.M. van Loosdrecht (2014), Full-scale Partial Nitritation/Anammox Experiences - an Application Survey, Water Research
25%
75%
>100 Full-scale Installations
Municipal
Industrial
Status in North America – DEMON – HRSD York River; Started October 2012; operating – ANITA Mox – HRSD James River; Started November 2013; operating
– DEMON – Harvest Power/Reedy Creek, FL; started January 2014; operating
– DEMON – Alexandria, VA; in construction – ANITA Mox – South Durham, NC; in construction – DEMON – Philadelphia, PA; 90% design – DEMON- Guelph, Ontario; in construction – DEMON – Pierce County, WA; pilot complete; in construction – DEMON – DC Water Blue Plains; in construction – ANITA Mox – Chicago Egan MWRDGC; in construction – DEMON – Greeley, CO, in construction
– DEMON – New York DEP; pilot completion recent – ANITA Mox – LA County San District; pilot completion recent – DEMON – Chicago Egan MWRDGC; pilot completion Feb 2013, in construction – ANITA Mox - Denver MWRD; pilot completion Feb 2013, in design – MBBR-style process – New York DEP; pilot ongoing
– DEMON - Alexandria, VA + DCWater pilot (no cyclone) – DEMON – New York DEP + DCWater pilot (no cyclone)
DEMON technology
14 14
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
15
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
16
DEMON at HRSD York River (15 MGD)
DEMON
DENITE FILTERS
HEADWORKS
AERATION BASINS
ANAEROBIC DIGESTION
THICKENING
DEWATERING
Implementation of DEMON at York River
19
Hydrocyclone for Biomass Wasting
• Retain anammox in small dense granules • SRT of anammox granules >> SRT of AOB,
NOB, heterotrophs, debris • Create “washout” conditions for NOB • Control activity of AOB population
DEMON feed Overflow Underflow
DEMON @ DC Water
ANITA MOX technology
ANITA Mox Process Components
Aeration System Instrumentation Centrate Feed
Mixers and Heaters K5 Media Media Retention 23
• Centrate Feed Control • Aeration Control
– Continuous and Intermittent – Four Different Modes
1. Airflow (scfm) 2. Fixed DO 3. Floating DO 4. pH-based DO or airflow
– Low pH air shutoff and air-on setpoints
• Mixer Control
Process Control
HRSD James River Treatment Plant (20 MGD)
ANITA™Mox Sidestream Deammonification MBBR
Biofilm Growth
Seed media 2/26/14
New media 4/10/14
Seed media 4/10/14
New media 2/26/14
New media 7/15/14
Seed media 7/15/14
Seed media 12/12/13
New media 12/12/13
Lesson learned… • Both processes are robust • Neither are “plug and play” • Huge excess of anammox activity is
accumulated • Anammox are not the issue… • All issues/problems related to slowing of
AOB kinetics, requires additional aeration = NOB
• Operator training issues are no big deal (with good centrate equalization)
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What`s next?
29
Minimum energy consumption
for concentration and polishing of remaining C and
N
Maximum energy recovery from concentrated organics
anammox in side line anammox in main line -27 Wh IE-1 d-1 +10 Wh IE-1 d-1
anammox
Mainstream Deammonification
• Main driver @ DC Water: methanol savings 1. Treat part of N-load in sidestream deammonification
system 2. Obtain mainstream short-cut nitrogen in main line
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
$0
$2
$4
$6
$8
$10
$12
$14
0% 20% 40% 60% 80% 100%
Payb
ack
Peri
od, Y
rs
Cost
Sav
ings
, $M
M/Y
r
Nitrogen Removed by Deammonification, %
Cost Savings
Carbon Electricity Total Cost Payback (Years)
Take homes
• Sidestream deammonification is established technology: – Small systems – No chemical costs – Energy savings
• Mainstream deammonification is the future towards energy autarky – Make right technology choice right now