Upgrading WRFs for Biological Nutrient Removal

OWEA Annual Technical Conference and Exhibition

June 25, 2015

• Permitting and Planning

• BNR Overview

• Case Example

• Innovative Approaches

Agenda

Proactive Participation in NPDES Nutrient Permits Can Save Millions

Brown and Caldwell 3

HRSD, Meeting Minutes for

3/23/2010,

“Traditional” Limits • Weekly/Monthly

• Annual, 6-month, or Seasonal

More Recent

• Max day limits - “Stringent” Ammonia and Ultimate Oxygen Demand

• 5-Year

• Bubble Permits • HRSD TN and TP

• Compliance flexibility – Focus on most cost effective upgrades instead of upgrading each WRF

Implementation Periods • 2-4 permit cycles for low nutrients (typ)

NEORSD P Removal - Impact of Averaging Period

Averaging Period

Filtration Capacity Required, mgd

0.5 mg/L TP 0.3 mg/L TP

Easterly (100 mgd annual, 400 mgd peak)

30 Day Average 55 200

90 Day Average 47 150

180 Day Average 43 140

Typical Nutrient Removal Planning Scenarios

Item Ammonia

mgN/L

Total

Nitrogen,

mgN/L

Total

Phosphorus,

mgP/L

Nitrification Varies -- --

Biological Nutrient Removal -- <8 to 10 <1.0

Enhanced Nutrient Removal -- <3 to 4 <0.3

ENR and beyond -- <2 to 3 <0.05 to 0.1

• Different Solutions when overlaying permit averaging

Key Source Material: Research by the Water Environment Research Foundation

• Nutrient impacts are seldom responsive to short term variations

• Study of long term statistics on the performance on exemplary nutrient removal plants

• Examples of nutrient permit bases

• Conclusions about type of technology on performance statistics

Bott and Parker, 2011

Key Source Material: Research by WERF Nutrient Management Vol. 2-Bott & Parker 2011

Study of long term statistics on performance of exemplary nutrient removal systems

% of Values Less Than or Equal to Indicated Value

0.01 0.1 1 10 30 50 70 90 99 99.9 99.99

TP o

r OP

(mg

P/L

)

0.001

0.01

0.1

1

TP

OP

Ln-Normal Values

% of Values Less Than or Equal to Indicated Value

0.01 0.1 1 10 30 50 70 90 99 99.9 99.99

TP o

r OP

(mg

P/L

)

0.001

0.01

0.1

1

TP

OP

Ln-Normal Values

% of Values Less Than or Equal to Indicated Value

0.01 0.1 1 10 30 50 70 90 99 99.9 99.99

TP o

r OP

(mg

P/L

)

0.001

0.01

0.1

1

TP

OP

Ln-Normal Values

% of Values Less Than or Equal to Indicated Value

0.01 0.1 1 10 30 50 70 90 99 99.9 99.99

TP o

r OP

(mg

P/L

)

0.001

0.01

0.1

1

TP

OP

Ln-Normal Values

Daily Weekly

Monthly Annual

N Removal Plants

• 4- or 5-stage Bardenpho plants almost meet TN=3

mg/L, 95% of time; 10 Florida plants achieve 3.5

mg/L. Cold climate Kalkaska plant may reach 3.0

mg/L TN

• Only 4 plants identified meeting max day effluent

NH4-N criterion of 4 mg/L – additional facilities

likely required for reliability

BNR Upgrade Overview

Nitrifying Activated Sludge Plant

Increase SRT to 7.5 -10 days

Additional Bioreactor : 2x to 3x

AEROBIC CLARIFIER

RETURN SLUDGE WASTE SLUDGE

EFFLUENT

Adding Bio-P to Nitrification

Selector:

15-20% Total Volume

Struvite Control

AEROBIC CLARIFIER

RETURN SLUDGEWASTE SLUDGE

EFFLUENT

ANAEROBIC AEROBIC CLARIFIER

RETURN SLUDGEWASTE SLUDGE

EFFLUENT

ANAEROBIC

Capacity Loss ≈ 0

TP < 0.6-1.0 mg /L

(Monthly)

Total Nitrogen Removal

ANOXIC AEROBIC CLARIFIER

RETURN SLUDGE

MIXED LIQUOR RECYCLE

WASTE SLUDGE

EFFLUENT

ANAEROBIC

Anoxic Zone:

≈ 30% Total Volume

TN < 10 mg /L

(Monthly)

Capacity Loss ≈ 20%

Combining TP and TN removal

Struvite Control

TP < 0.7-1 mg/L

TN < 10 mg /L

(Monthly)

ANOXIC AEROBIC CLARIFIER

RETURN SLUDGE

MIXED LIQUOR RECYCLE

WASTE SLUDGE

EFFLUENT

ANAEROBIC

Anoxic Zone:

≈ 30% Total Volume Selector:

15-20% Total Volume

Capacity Loss ≈ 25-30%

Further Reducing Phosphorus Discharges

Alum

Dual Media or

Deep Bed Filters

Membranes

Scenario Effluent TP, mg P/L

Monthly Annual

Filters <0.3 <0.2-0.3

Membranes <0.2 <0.1-0.2

Alum

Dual Media or

Deep Bed Filters

Membranes

Scenario Effluent TP, mg P/L

Monthly Annual

Filters <0.1 <0.1

Membranes <0.1 <0.1

CoMag w/o Filters <0.1 <0.1

Process Type

Performance of Exemplary Plants,

Max Month Performance,EPA and

WERF Study, TN mg/L

Influent Carbon for Denitrification 4 to 11

Influent Carbon and External Carbon (with

Filtration) <4

Nitrify First, Denitrify with External Carbon

(with Filtration) <3

Combination (with Filtration) 3 to 4

Total Nitrogen Removal: Building on what you own

Influent Carbon and External Carbon (with Filtration) 5-Stage Bardenpho Process

AEROBIC ANOXIC AEROBIC CLARIFIER

RETURN SLUDGE

MIXED LIQUOR RECYCLE

WASTE SLUDGE

EFFLUENT

ANOXIC ANAEROBIC

Annual TN= 4 mg N/L with filtration

CARBON

16

Nitrify First, Denitrify with External Carbon (with Filtration)

ORGANIC

CARBON

ANOXIC AEROBIC CLARIFIER

RETURN SLUDGE

Dentrification

Activated sludge

Deep Bed

Denite filters

Biologically

activated filters

(Biostyr, Biofor)

AEROBIC CLARIFIER

RETURN SLUDGE

WASTE SLUDGE

ANAEROBIC

Annual TN= 3-4 mg N/L with filtration

Case Example – Progression from Nitrification to BNR/ENR

Step Feed Nitrifying Activated with Seasonal Nitrification Limit

• Summer: 2 mg/L NH3-N

• Winter: 5-15 mg/L NH3-N

• No P limit

• Phase 1 Upgrades

• Reduce TP to 1 mg/L

• Phase 2 Upgrades

• TP: 0.3 to 0.1 mg/L

• TN: 4 to 10 mg N/L

Phase 1 Maximized Capacity to Save $100M+

Selector Zones

Phase 1 – Reduce TP to 1.0 mg/L Results

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Eff

lue

nt

TP

, m

g/L

Daily

Daily 30-DMA Annual Moving

Phase 2: Reduced Phosphorus Discharges 2A – 0.3 mg/L (Filters) 2B – 0.1 mg/L

2A

2B

Existing Nitrogen Discharges

0

5

10

15

20

25

30

35

1/1

/20

09

2/8

/20

09

3/1

8/2

00

9

4/2

5/2

00

9

6/2

/20

09

7/1

0/2

00

9

8/1

7/2

00

9

9/2

4/2

00

9

11

/1/2

00

9

12

/9/2

00

9

1/1

6/2

01

0

2/2

3/2

01

0

4/2

/20

10

5/1

0/2

01

0

6/1

7/2

01

0

7/2

5/2

01

0

9/1

/20

10

10

/9/2

01

0

11

/16

/20

10

12

/24

/20

10

1/3

1/2

01

1

3/1

0/2

01

1

4/1

7/2

01

1

5/2

5/2

01

1

7/2

/20

11

8/9

/20

11

9/1

6/2

01

1

10

/24

/20

11

12

/1/2

01

1

1/8

/20

12

2/1

5/2

01

2

3/2

4/2

01

2

5/1

/20

12

6/8

/20

12

7/1

6/2

01

2

Effl

ue

nt

Tota

l N

itro

gen

, m

g N

/L

NO3-N Ammonia-N Organic N NO2-N

Phase 2 – TN Reduction Using Influent Carbon

Monthly TN= 10 mg N/L

RAS

SI

To FST

Anoxic RAS Anaerobic

300% SI

Phase 2 - Influent Carbon for TN Reduction

Monthly TN= 10 mg N/L

Monthly TP = 1.0 mg/L

Phase 2 – Nitrify First, Denitrify with External Carbon Denite Filters

• TP < 0.3 mg/L

• TN< 4 or < 10 mg N/L

Phase 2 – Nitrify First, Denitrify with External Carbon Denite MBBR Tert. Clarifiers Membranes

• TP < 0.1 mg/L

• TN< 4 or < 10 mg N/L

Innovation

Why/How to Innovate in Our Industry?

Brown and Caldwell 28

Cost,

Energy,

Footprint Efficiency =

Wh

y H

ow

Basic

Research

Pilot-scale

Research

Pilot

BNR

Demonstration-scale

Research

Generation 1st

Sustainability

“S” Curve for Innovation

Brown and Caldwell 29

Laggards?

Late

Majority

Early

Majority

Early

Adopters

Second

Generation

De

velo

pm

en

t/N

um

be

r In

sta

lle

d

First Generation

First

Demonstration

Pilot

Time Parker’s and Roger’s “S” Curves Combined for

Status of Technology and Type of Adopter

Mature

Technology

Innovative

(Increased Risk)

Conventional

(Low risk)

Innovators

• Dixie Drain, Boise ID: P removal-water trading

• Littleton-Englewood CO: Effluent recycle for TN

• Marley Taylor WRF MD: BioMag™ process

• Nampa ID: P removal, A/O MLE, groundwater infiltrn

• St Petersburg FL: Mainstream Nitrite shunt

• Chambers Creek, Tacoma WA: Demon® sidestream N

• Minneapolis (MCES): Air Mixed Selectors

BNR Innovation Examples

Brown and Caldwell 31

• TMDL allocated point sources at 0.07 mg/L TP

• City of Boise strategy:

• Treat to ~0.5 mg/L at WWTP

• Treat agricultural return flows

• Projected cost savings: $40 million

Dixie Drain Phosphorus Trade, Boise River

Brown and Caldwell 32

Nitrified Effluent Recycle Reduces TN and Methanol Needs

Phase 2

TN Reduction

Headworks odor suppression

Methanol savings: $0.25 M/yr

Marlay Taylor WRF BioMag Process

• Clarifier SLR to 100 lb/sf-d

• Plant Capacity increased 2x-3x

• 30-40% adder to BNR energy

• ESS = 1-3 mg/L (tertiary filters)

St Petersburg Southwest Water Reclamation Facility - Nitrite Shunt

Nitrite Shunt

Brown and Caldwell 36

≈ 25% Oxygen Reduction

≈ 40% carbon and biomass reduction

Control

Parameter

Condition Action

NH4+ Control

NH4+ < 1.0 mg N/L

Reduce SRT

DO = 0.1 mg/L.

NH4+ > 3.0 mg N/L

Increase SRT

DO = 0.1 to 0.3 mg/L.

NO3- Control

NO3- > 1.0 mg N/L

Decrease DO =0.1 mg/L

Monitor NO2- accumulation in basin

NO3- < 1.0 mgN/L No action required

NO2- Control Monitor effluent NO2

- as surrogate measurement of shunt

performance

Creating Conditions for Nitrite Shunt

Southwest Water Reclamation Facility - Nitrite Shunt Operations

0

2

4

6

8

10

7/28/13 8/4/13 8/11/13 8/18/13 8/25/13 9/1/13

Nit

roge

n S

pec

ies,

mg/

L

Ammonia Nitrite Nitrate

0

1

2

3

4

5

07/28/13 08/04/13 08/11/13 08/18/13 08/25/13 09/01/13To

tal

Ph

osp

ho

rus,

mg

/L

Influent Effluent

Aeration Demands Reduced 40- 50%

• $6 million in capital & O&M savings

• Multi-process to address lack of nitrogen limits in permit

Chambers Creek – Demon® Process

Brown and Caldwell 39

Air Mixed Selectors

Air Mixed Selector – Typical Basin Profile

0

5

10

15

20

25

30

35

40

Selector End Pass

1

End Pass

2

Mid Pass

3

Selector End Pass

1

End Pass

2

Mid Pass

3

Ph

osp

ha

te, m

g P

O4

-P/L

11-Mar-15

AB-0 AB-6

AM Profile PM Profile

Air Mixed Selectors

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

1/1

/2001

7/1

/2001

1/1

/2002

7/1

/2002

1/1

/2003

7/1

/2003

1/1

/20

04

7/1

/2004

1/1

/2005

7/1

/2005

1/1

/2006

7/1

/2006

1/1

/2007

7/1

/2007

1/1

/2008

7/1

/2008

1/1

/2009

7/1

/2009

1/1

/2010

7/1

/2010

1/1

/2011

7/1

/2011

1/1

/2012

7/1

/2012

1/1

/2013

7/1

/2013

1/1

/2014

7/1

/2014

1/1

/2015

Eff

luen

t T

ota

l P

ho

sph

oru

s, m

g/L

Daily 12-Month Rolling Average

New Industry On-line

Anaerobic Digesters

Operational

Reduced DO

EBPR

Stress TestingEBPR

ImprovementsLiquid Stream and

Digester Construction

Pseudo Selector

On-line

Thank you! Q&A

Don Esping, P.E.

DEsping@BrwnCald.com