1. Nutrient recovery at the ashbridges bay wastewater treatment plant
WEAO SDC 2015
Tania
Good morning everyone, we hope you are enjoying the conference. We are all here today to talk about Nutrient Recovery at the Ashbridges Bay Wastewater Treatment Plant.
My name is Tania Farah, this is Amal Ghamrawi and Rose Zhao who will now introduce us to the Ashbridges Bay Wastewater Treatment Plant.
Tania Farah
Amal Ghamrawi
David Tran
Rose Zhao

2. Ashbridges Bay wASTEwater Treatment Plant
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Ashbridges Bay wASTEwater Treatment Plant
ECA Effluent Discharge Limits
Parameter
Limit
SS [mg/L] 25
SS Loading Rate (kg/day)
20,450
CBOD5 [mg/L]
CBOD5 (kg/day) pH
6 – 8.5
TP [mg/L] 1
TP Loading Rate (kg/day)
818
E-Coli [CFU/100 mL]
200
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
Rose
ABTP is located in Toronto and it discharges effluent into Lake Ontario. It is the largest secondary WWTP in Canada, with a nominal capacity of 818 MLD and an approximate sewershed of 25,000 ha. It is a conventional activated sludge plant
The influent to the plant also include sludge flows from two other plants in Toronto—Humber Treatment Plant and North Toronto Treatment Plant.
These are the discharge effluent guidelines that ABTP is required to meet and are currently meeting.
The plant has high nitrogen loading in the mainstream because it accepts sludge from two other plants and recycles the anaerobic digestate
EFFLUENT DISCHARGE REQUIREMENTS.

3. Toronto Water Strategic Plan
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Toronto Water Strategic Plan
Mission Statement
Guiding Principles
Provide quality water services to the Toronto community while protecting public health, safety and property in an environmentally and a fiscally responsible manner
Continuous Service Delivery Improvement
Financial Vitality, Viability and Sustainability
Operational Excellence
Infrastructure Management
Employer of Choice
Rose
ABTP is located in Toronto and it discharges effluent into Lake Ontario. It is the largest secondary WWTP in Canada, with a nominal capacity of 818 MLD and an approximate sewershed of 25,000 ha. It is a conventional activated sludge plant
The influent to the plant also include sludge flows from two other plants in Toronto—Humber Treatment Plant and North Toronto Treatment Plant.
These are the discharge effluent guidelines that ABTP is required to meet and are currently meeting.
The plant has high nitrogen loading in the mainstream because it accepts sludge from two other plants and recycles the anaerobic digestate
EFFLUENT DISCHARGE REQUIREMENTS.

4. ABTP Current initiatives
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
ABTP Current initiatives
Water Quality Improvement
Resource Recovery Initiatives
Process changes to encourage nitrification
Increased SRT and DO concentrations
Improved DO control instrumentation programming
Additional 10 million kWh is used per year
Recycling of effluent water for non-potable use
Use of digester gas for process and building heat
Beneficial use of biosolids
Rose
ABTP is located in Toronto and it discharges effluent into Lake Ontario. It is the largest secondary WWTP in Canada, with a nominal capacity of 818 MLD and an approximate sewershed of 25,000 ha. It is a conventional activated sludge plant
The influent to the plant also include sludge flows from two other plants in Toronto—Humber Treatment Plant and North Toronto Treatment Plant.
These are the discharge effluent guidelines that ABTP is required to meet and are currently meeting.
The plant has high nitrogen loading in the mainstream because it accepts sludge from two other plants and recycles the anaerobic digestate
EFFLUENT DISCHARGE REQUIREMENTS. 4

5. PHASE I PHASE II Objective of Project
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Objective of Project
PHASE I
PHASE II
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
Stream
TKN
(mg/L)
Ammonia (mg/L)
Influent
50.9
25.4
Centrate
907
590
Amal
ABTP is located in Toronto and it discharges effluent into Lake Ontario. It is the largest secondary WWTP in Canada, with a nominal capacity of 818 MLD and an approximate sewershed of 25,000 ha. It is a conventional activated sludge plant
The influent to the plant also include sludge flows from two other plants in Toronto—Humber Treatment Plant and North Toronto Treatment Plant.
These are the discharge effluent guidelines that ABTP is required to meet and are currently meeting.
The plant has high nitrogen loading in the mainstream because it accepts sludge from two other plants and recycles the anaerobic digestate
EFFLUENT DISCHARGE REQUIREMENTS.

6. PHASE I Planned approach
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
PHASE I Planned approach
Centrate Treatment Options
Phase I-1
Phase I-2
Resource Recovery
Treatment
Ammonia Stripping
Amal
Ion Exchange
Struvite Recovery 6

7. Centrate Characteristics
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
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
Amal
The activated sludge is settled in the final clarifiers, and then is thickened through dissolved air flotation. It then enters anaerobic digestion where organic matter is broken down, and where bound ammonia is released. This is then dewatered through the use of centrifuges and then the liquid stream is recycled into the secondary treatment. The advantages of centrate only treatment include a concentrated stream of nutrients and a smaller volume – a nominal flow of 8 MLD vs. 818 MLD.
The Phosphorous content in the centrate is assumed to be 20% of the influent.

8. Nutrient Recovery Options
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Nutrient Recovery Options
Up to 96% of N as NH3/NH4+ as Ammonium Nitrate/Sulphate Fertilizer
Requires: T>60°C
Problems: carbonate scaling, noise, air pollution and high pH
Ammonia Stripping
Up to 97% N as NH4+ or up to 90% N as NO3 as a fertilizer
Requires: extensive pretreatment
Problems: complex bed regeneration and extensive pretreatment
Ion Exchange
Up to 90%-P & up to 40%-NH3 as slow-release fertilizer
Requires: addition of magnesium source and pH≈7-8
Problems: possible crystallization in pipes
Struvite Recovery
amal
Ammonia Recovery:
Ammonia stripping recovers nitrogen only, up to 80-90% N recovery through the volatilization of gaseous ammonia (WERF, 2014). The products that can be recovered are ammonium nitrate and ammonium sulphate. Air stripping only removes ammonia and ammonium from wastewater, it does not recover organic N or nitrate. The pH requirements of the system require it to be at least greater than 10 and an operating temperature of at least 60 degrees C. Ammonia stripping is done via air, steam or vacuum which all require energy. The operating costs are high.
There are a lot disadvantages associated with ammonia recovery.
High operation and maintenance costs
pH and temperature of air and water must remain stable and high
Large air requirements (for air stripping)
Higher pH can absorb CO2 from the air and cause carbonate scaling –which may or not be removed
Water must be re-pumped to stripping tower
In freezing conditions, air must be sufficiently heated –fogging and icing decrease removal efficiency
Ammonia is discharged to the environment and air pollution problems may arise from ammonia and sulphur dioxide reactions
Noise may be an issue
High pH wastewater can corrupt the wood packing in stripping tower
Ion Exchange:
Ion exchange for nitrogen control is when, “ions of a given species are displaced from insoluble exchange materials by ions of a different species in solution,” (WERF, 2014), ammonium is removed. It has not really been applied in wastewater treatment due to concerns about the regeneration bed, complexity and high costs. Ion Exchange has been reported to be 15 times the cost of nitrification and denitrification, depending on the lime added.
Struvite Recovery:
Struvite is a crystalline material that commonly precipitates within wastewater treatment plants, often causing issues with the clogging of pipes and pumps. Direct extraction of this struvite as P from biosolids can reduce the problem and recover P and N. It requires the addition of a magnesium source and a pH adjustment Struvite recovery is the most feasible out of all of these processes and has been demonstrated full scale at several plants. Has several proprietary processes.

9. Struvite Recovery options
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Struvite Recovery options
Factor
DHV Crystalactor®
Multiform Harvest Inc. Crystallizer
NuReSys®
Process
Ostara Pearl® Process
Pacques
PHOSPHAQ™
Country 5 10
Reactor Type
Chemicals Used
HRT 15 8
P Reduction 7
NH3-N Reduction
Full Scale Plants 3 2
Odour Control
Capital Costs 20 9
TOTAL
100
755
670
440
770
465
amal
Struvite Recovery is provided through various proprietary processes.

10. oSTARA PEARL® PROCESS Mg+2 + NH4+ + PO43- + 6H2O  MgNH4PO46 H2O
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
oSTARA PEARL® PROCESS
Mg+2 + NH4+ + PO H2O  MgNH4PO46 H2O
The OSTARA Advantage
Up to 94% PO43- and 30% NH3 removal efficiencies
Canadian
8 Full Scale Municipal Installations
Renewable 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
amal
The formation of struvite occurs under favorable conditions, including when concentrations of soluble magnesium (Mg+2), ammonium (NH4+), and orthophosphate (PO4-3) exceed levels which promote the formation of crystals, sometimes referred as super- saturation. These three ions have to be in a molar ratio of 1:1:1.
Ostara

11. OSTARA PEARL® PROCESS 25% Influent P Improved biosolids cake
4% increase in solid content
20% decrease in volume
OSTARA PEARL® PROCESS
25% Influent P
Waste Activated Sludge
Stripping To
Remove Internal Phosphorous
Amal
20% Influent P
Ostara

12. EXPECTED EFFLUENT CHARACTERISITCS
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
EXPECTED EFFLUENT CHARACTERISITCS
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
Centrate
Flow (m3/d)
7273
TSS (mg/L)
1959
PO4-P (mg/L)
139
NH3-N (mg/L)
590
TKN (mg/L)
907
Amal
Ostara
2 Pearl Reactors 12

13. Nutrient removal Centrate Treatment Options Resource Recovery
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Nutrient removal
Centrate Treatment Options
Resource Recovery
Biological Treatment
Nitrification-Denitrification
Tania
Nutrient removal consists of two different treatments. One approach resource recovery, which is the physical or chemical treatment that Amal was just discussing, and the other is biological treatment.
This treatment removes nitrogen out of wastewater before it is discharged into the water, through the use of microorganisms.
That being said, there are multiple biological processes such as:
Nitrification-Denitrification
Nitritation-Denitritation
Partial Nitritation-Anammox
Nitritation-Denitritation
Partial Nitritation-Anammox

14. Biological Treatment of Nitrogen
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Biological Treatment of Nitrogen
Biological
1 mole Nitrate
40% C
25% O2
Nitrification-Denitrification
Nitritation-Denitritation
1 mole Nitrite
1 mole Nitrite
60% C
75% O2
Partial N-Anammox
Tania
Nitrification-Denitrification is the conventional process, making it the least efficient. As you can see in the figure, the first half of this process requires 100% oxygen and the second half requires 100% of a carbon source.
1 mole Ammonia
½ mole Nitrogen Gas

15. Biological Treatment of nitrogen
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Biological Treatment of nitrogen
Biological
1 mole Nitrate
40% C
25% O2
Nitrification-Denitrification
Nitritation-Denitritation
1 mole Nitrite
1 mole Nitrite
60% C
75% O2
Partial N-Anammox
Tania
Nitritation-Denitritation is a more advanced process. It removes a part of the conventional process, making it efficient.
Compared to the conventional, this process requires 75% oxygen and 60% of a carbon source.
1 mole Ammonia
½ mole Nitrogen Gas 15

16. Biological Treatment of nitrogen
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Biological Treatment of nitrogen
Biological
1 mole Nitrate
40% C
25% O2
Nitrification-Denitrification
Nitritation-Denitritation
75% O2
½ mole Nitrite
1 mole Nitrite
60% C
40% O2
Partial N-Anammox
Tania
The most advanced treatment is Partial Nitritation-Anammox, where Anammox stands for anaerobic ammonia oxidation.
It reduces the process by half, and only requires around 40% of oxygen. It does not need a carbon source, making it the most efficient treatment out of the biological treatments.
The nitrogen gas is produced under anoxic conditions with the use of autotrophic bacteria known as anammox bacteria.
1 mole Ammonia
½ mole Nitrogen Gas 16

17. Partial Nitritation-Anammox Processes
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Partial Nitritation-Anammox Processes
DEMON® SBR
Partial Nitritation-Anammox
ANITATM Mox MBBR
Tania
There are multiple configurations designed for this process:
DEMON® Suspended Growth Sequence Batch Reactor (SBR) Process
ANITATM Mox Moving-Bed Biofilm Reactor (MBBR) Process
Two-Stage SHARON®-ANAMMOX® Process
2-Stage SHARON®-ANAMMOX® 17

18. Partial Nitritation-Anammox Processes
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Partial Nitritation-Anammox Processes
DEMON® SBR
ANITATM Mox
SHARON®-ANAMMOX®
TN Removal (%) 85 80 90
Energy (kW-h kg-1)
4.17
Start-Up Time (Months)
2-5
3-4
3-5
Operator Attention
High
Low
Maintenance
Medium
Tania
All three of these processes have a common outcome. The difference is their demands.
The best two alternatives are DEMON and ANITATM Mox. There is not a large energy demand difference nor TN removal between the two, thus those cost differences will not be great. Now ANITATM Mox has a higher energy demand, however, it requires less operator attention and lower maintenance. These demands contribute to annual costs, making ANITATM Mox the better option. 18

19. Preliminary Reactor Characteristics
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Preliminary Reactor Characteristics
Soluble BOD Removal
ANITATM Mox
Nitrification
Volume
1200 m3
3500 m3
900 m3
SWD
5.0 m
Air Flow Requirement
6500 Nm3/h
14000 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/L
Dissolved Air Flotation Unit
Effluent TKN
40-50 mg/L
Tania
According to Mr. Pearce, the Sales Director at Veolia Water Technologies, the ANITATM Mox system design would be composed of 3 reactors in series:
Reactor 1: Soluble BOD Removal Reactor
Reactor 2: ANITATM Mox Reactor
Reactor 3: Nitrification Reactor
The goal of the first reactor is to remove the soluble biodegradable carbon upstream of the ANITATM Mox reactor. This is done to prevent competition between the heterotrophic biomass and the anammox bacteria. An additional third reactor is needed to complete nitrification due to the treated effluent objective being 51 mg/L TKN.
In order to reach that effluent TKN requirement, a solid/liquid separation system, typically a DAF unit is needed. With 90% TSS removal, the DAF effluent TKN would be about mg/L.
Dissolved air flotation (DAF) is a water treatment process that clarifies wastewater by the removal of suspended matter. The removal is achieved by dissolving air in the wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank. The released air forms tiny bubbles which adhere to the suspended matter causing it to float to the surface where it is then removed by a skimming device.
Soluble BOD Removal Reactor
ANITATM Mox Reactor
Nitrification Reactor
Dissolved Air Flotation Unit 19

20. Lessen Environmental Impact
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Design BASIS
TN removal in addition to ammonia removal
Improved final effluent
Improving Operations
Reduce Cost and Energy
Ferric chloride eliminated
Coarse to fine diffusers
Non-chemical sludge
Less sludge volume
Safer to use on land
Lessen Environmental Impact
rose
Requirement for:
Struvite Recovery
Resource Recovery 20

21. PROCESS SELECTED: A2O NMLR Secondary Effluent Influent
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
PROCESS SELECTED: A2O
NMLR
Secondary Effluent
Influent
Secondary Clarifier
Anaerobic
Anoxic
Aerobic
rose
The treatment process applies anaerobic, anoxic, and aerobic sequence with sludge and internal cycle. Nitrate is recycled from the aerobic zone to the anoxic zone for denitrification. The use of the anoxic zone minimizes the amount of nitrate fed to the anaerobic zone in the return activated sludge
Anaerobic and anoxic will be added to retrofit the existing nitrification system; The existing plant does not require denitrification; however, anoxic zone is retrofitted to the treatment to ensure reliability of the anaerobic zone and process efficiency. To achieve sufficient nutrient removal, reactor sizing and performances is determined base on mass balance of the influent characteristic and typical design parameters.
RAS
VFA
WAS 21

22. DESIGN SPECIFICATION 25.4% 1.5 h 25.4% 1.5 h 49.2% 2.9 h Parameter
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
DESIGN SPECIFICATION
25.4%
1.5 h
ANAEROBIC
25.4%
1.5 h
ANOXIC
Aeration Tanks
49.2%
AEROBIC
2.9 h
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
mg/L
10 mg/L
rose 22

23. ANITATM Mox Overall Benefits
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
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
Tania
The overall project scope of ANITATM Mox, including construction and installation: ≈ $20-25 million
The service life of carries with normal use in a steel tank is more than 20 years and more than 15 years in a concrete tank with smooth walls.
And just a quick recap:
No additional chemicals are needed once the starting period is over, no carbon source is needed, pH is self-regulated, DO is automatically adjusted.
Does not require any heavy maintenance; all of the online sensors need to be calibrated regularly, but the equipment inside the reactor are maintenance-free.
After start-up, the process is operated automatically from the programmable controller, making it simple for an operator to control the process operation. 23

24. Ostara Overall benefits
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Ostara Overall benefits
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
$317,00
Capital Cost of Ostara:$20 million
Includes 2 Pearl® Reactors, a building and WASSTRIP® Tank
Expected Annual Savings: $5 million
Expected Payback Period: 4-6 years
Amal
With the implementation of the WASSTRIP® and Pearl® process, anaerobic digestion will become more efficient and most plants have seen about a 15% reduction in sludge production. Therefore costs for sludge handling costs, dewatering and thickening polymers will be reduced. Additionally, for every kg of ammonia recovered in the Pearl® Process it is approximated that at least $1 can be saved on power costs. It is assumed that the plant spends around $200/tonne for sludge handling and disposal.
The thickening polymer reduction is solely based on the reduction of chemical sludge produced from switching to Bio-P.
While the dewatering polymer is savings from the anaerobic digestion improvement and the decrease in chemical sludge.
ABTP Expected Production: tonnes/day Crystal Green® Fertilizer
Ostara
WERF, 2014 24

25. A2/O Overall Benefits Estimated Annual Savings: $3.6 million
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
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
Amal 25

26. Updated Schematic of ABTP
Introduction
Phase I
Nutrient Recovery
Nutrient Removal
Phase II: Resource Recovery
Overall Benefits
Conclusion
Updated Schematic of ABTP
Phase II
Phase I-2
Phase I-1
rose

27. Acknowledgements Dr. Rajesh Seth University of Windsor
Associate Professor
Department of Civil and Environmental Engineering
Faculty Advisor
Dr. Edwin Tam
Sailesh Singh
Golder Associates
Water Treatment Engineer
Industry Advisor
Michael Reaume
Stantec Consulting
Engineer in Training
Derek Lycke
Ostara Nutrient Recovery Technologies
Technical Director, Nutrient Recovery Solutions
David Pearce
Veolia Water Technologies
Sales Director