WEAO SDC 2015

Nutrient recovery at the ashbridges bay wastewater

treatment plant

Tania Farah Amal Ghamrawi

David TranRose Zhao

Ashbridges Bay wASTEwater Treatment Plant

ABTP Fast Facts

Location City of Toronto

Effluent Discharge

Lake Ontario

Nominal Capacity

818 MLD

Equivalent Population

1,524,000

Sewershed Area Serving

25,000 ha

ECA Effluent Discharge Limits

Parameter Limit

SS [mg/L] 25

SS Loading Rate (kg/day)

20,450

CBOD5 [mg/L] 25

CBOD5 (kg/day) 20,450

pH 6 – 8.5

TP [mg/L] 1

TP Loading Rate (kg/day)

818

E-Coli [CFU/100 mL] 200

2

Toronto Water Strategic Plan

Mission Statement

Provide quality water services to the Toronto community while protecting public health, safety and property in an environmentally and a fiscally responsible manner

Guiding Principles

I. Continuous Service Delivery Improvement

II. Financial Vitality, Viability and Sustainability

III. Operational Excellence

IV. Infrastructure Management

V. Employer of Choice

3

ABTP Current initiatives

Water Quality Improvement

Process changes to encourage nitrification Increased SRT and DO

concentrations

Improved DO control instrumentation programming

Additional 10 million kWh is used per

year

Resource Recovery Initiatives

Recycling of effluent water for non-potable use

Use of digester gas for process and building heat

Beneficial use of biosolids

4

Objective of Project

Reduce the TKN and ammonia of the centrate streams to approaching plant influent levels.

Two additional areas in which the plant could adopt a resource recovery approach to:

Benefit the operations Lessen the

environmental impact Reduce the cost of

treatment

PHASE I PHASE II

5

PHASE I Planned approach

Centrate Treatment Options

Resource Recovery

Treatment

Struvite Recovery

Ammonia Stripping

Ion Exchange

Phase I-1

Phase I-2

6

Centrate Characteristics

Centrate Characteristics

Parameter Value

Nominal Centrate Flow (L/s)

84(8 MLD)

TKN (mg/L) 907

Ammonia (mg/L) 590

Phosphorous (mg/L) 139

TSS (mg/L) 1959

7

Nutrient Recovery Options

8

Struvite Recovery options

Factor DHV Crystalacto

r®

Multiform Harvest

Inc. Crystallize

r

NuReSys®

Process

Ostara Pearl® Process

PacquesPHOSPHAQ

™

Country 5 0 10 0 10 0

Reactor Type

5 10 10 0 10 0

Chemicals Used

10 0 10 10 10 0

HRT 15 10 10 8 10 0

P Reduction

15 10 8 0 8 7

NH3-N Reduction

15 10 0 0 10 10

Full Scale Plants

5 3 0 8 10 2

Odour Control

10 10 10 0 10 0

Capital Costs

20 7 5 9 0 10

TOTAL 100 755 670 440 770 465

oSTARA PEARL® PROCESSMg+2 + NH4

+ + PO43- + 6H2O MgNH4PO46

H2OThe OSTARA Advantage Up to 94% PO4

3- and 30% NH3 removal efficiencies Canadian 8 Full Scale Municipal InstallationsRenewable fertilizer production Reduces:

Chemical use Nutrient loads Operation and maintenance costs Greenhouse gas emissions

Process Requirements

MgCl2 6000 kg/day

NaOH 800 kg/day

Heat 16 GJ/day

Power 2350 kWh/day

10

Ostara

11

OSTARA PEARL® PROCESS

Waste Activated Sludge StrippingTo Remove Internal Phosphorous

Improved biosolids cake

4% increase in solid content

20% decrease in volume

25% Influent P

20% Influent P

Ostara

EXPECTED EFFLUENT CHARACTERISITCS

Centrate

Flow (m3/d) 7273

TSS (mg/L) 1959

PO4-P (mg/L)

139

NH3-N (mg/L)

590

TKN (mg/L) 907

WASSTRIP®

Flow (m3/d) 3391

TSS (mg/L) 500

PO4-P (mg/L)

374

NH3-N (mg/L)

30

Pearl® Effluent

Flow (m3/d)

10665

TSS (mg/L)

1495

PO4-P (mg/L)

34

NH3-N (mg/L)

331

TKN (mg/L)

547

Objective

Influent

Centrate

Ammonia (mg/L)

25.4 590

TKN (mg/L) 50.9 907

12

Ostara

Nutrient removal

Centrate Treatment Options

Resource Recovery

Biological Treatment

Nitrification-Denitrification

Nitritation-Denitritation

Partial Nitritation-Anammox

13

Biological Treatment of Nitrogen

Biological

Nitrification-Denitrification

Nitritation-Denitritation

Partial N-Anammox

1 mole Nitrate

1 mole Nitrite 1 mole Nitrite

1 mole Ammonia ½ mole Nitrogen Gas

25% O2

75% O2

40% C

60% C

14

Biological Treatment of nitrogen

1 mole Nitrate

1 mole Nitrite 1 mole Nitrite

1 mole Ammonia ½ mole Nitrogen Gas

25% O2

40% C

60% C

Biological

Nitrification-Denitrification

Nitritation-Denitritation

Partial N-Anammox

75% O2

15

Partial N-Anammox

Biological Treatment of nitrogen

1 mole Nitrate

½ mole Nitrite 1 mole Nitrite

1 mole Ammonia ½ mole Nitrogen Gas

25% O2

40% C

60% C

Biological

Nitrification-Denitrification

Nitritation-Denitritation 40% O2

75% O2

16

Partial Nitritation-Anammox Processes

Partial Nitritation-Anammox

DEMON® SBR

ANITATM Mox MBBR

2-Stage SHARON®-ANAMMOX®

17

Partial Nitritation-Anammox Processes

DEMON® SBR

ANITATM Mox

SHARON®-ANAMMOX®

TN Removal (%)

85 80 90

Energy (kW-h kg-1)

1.0-1.3 1.45-1.75 4.17

Start-Up Time (Months)

2-5 3-4 3-5

Operator Attention

High Low Low

Maintenance

High Low Medium 18

Preliminary Reactor Characteristics

Soluble BOD Removal

ANITATM Mox

Nitrification

Volume 1200 m3 3500 m3 900 m3

SWD 5.0 m 5.0 m 5.0 m

Air Flow Requirement

6500 Nm3/h14000 Nm3/h

5000 Nm3/h

Effluent NH4-N

441 mg/L 72 mg/L 30 mg/L

Effluent TKN -- 157 mg/L 111 mg/L

Effluent TSS -- -- 1500 mg/L

Alkalinity Consumption

-- 1600 mg/L 300 mg/L19

Dissolved Air Flotation Unit

Effluent TKN 40-50 mg/L

Design BASIS

Reduce Cost and Energy

Lessen Environmental

Impact

Improving Operations

Resource Recovery

• TN removal in addition to ammonia removal

• Improved final effluent

• TN removal in addition to ammonia removal

• Improved final effluent

• Ferric chloride eliminated

• Coarse to fine diffusers

• Ferric chloride eliminated

• Coarse to fine diffusers

• Non-chemical sludge• Less sludge volume • Safer to use on land

• Non-chemical sludge• Less sludge volume • Safer to use on land

• Requirement for: • Struvite Recovery

• Requirement for: • Struvite Recovery

20

PROCESS SELECTED: A2O

Anaerobic

Anoxic

Aerobic Second

ary Clarifier

Influent

VFA WAS

RAS

NMLR

Secondary Effluent

21

DESIGN SPECIFICATION

ANAEROBIC

ANOXIC

AEROBIC

25.4%

25.4%

49.2%

1.5 h

1.5 h

2.9 h

Aeration Tanks

Parameter

Value

Total Volume

201,902 m3

Total HRT 5.9 h

RAS 490,800 m3/d

MLSS 3,000 mg/L

Loading

Current A2O

TKN 9.72 mg/L

1.0 mg/L

Ammonia

7.72mg/L < 1.0 mg/L

TN 25 -30 mg/L

10 mg/L 22

ANITATM Mox Overall Benefits

Overall project scope: ≈ $20-25 million

Service Life: >20 years

No additional chemicals

No carbon source

pH is self-regulated DO is automatically adjusted

No heavy maintenance

Simple operation

23

Ostara Overall benefits

Capital Cost of Ostara:$20 million Includes 2 Pearl®

10000 Reactors, a building and WASSTRIP® Tank

Expected Annual Savings: $5 million

Expected Payback Period: 4-6 years

Ostara Savings

Ferric Chloride Elimination

$1,259,000

WAS Thickening Polymer

$138,000

Biosolids Dewatering Polymer

$775,000

Sludge Handling and Disposal

$2,467,000

N Removal $317,00ABTP Expected

Production: 15.2 tonnes/day Crystal Green® Fertilizer WERF,

2014

24

Ostara

A2/O Overall Benefits

Estimated Annual Savings: $3.6 million

Savings not quantified: switching from coarse to fine air bubble diffusers

A2O Savings

Ferric Chloride Elimination

$1,259,000

WAS Thickening Polymer $238,000

Biosolids Dewatering Polymer

$500,000

Sludge Handling and Disposal

$1,592,000

25

26

Updated Schematic of ABTP

Phase I-1

Phase I-2

Phase II

Acknowledgements

Dr. Rajesh SethUniversity of WindsorAssociate Professor

Department of Civil and Environmental Engineering

Faculty Advisor

Dr. Edwin TamUniversity of WindsorAssociate Professor

Department of Civil and Environmental Engineering

Faculty Advisor

Sailesh SinghGolder Associates

Water Treatment EngineerIndustry Advisor

Michael ReaumeStantec Consulting Engineer in Training

Industry Advisor

Derek LyckeOstara Nutrient Recovery

Technologies Technical Director, Nutrient

Recovery Solutions

David PearceVeolia Water Technologies

Sales Director

27