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