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Assessing the performance of cold climate natural
wetlands in the treatment of domestic wastewater
effluents in northern C...
Focus
• Wetlands are providing a treatment
benefit
• Assessment tools are available
• Wetlands could be part of a
hybridiz...
Background
• CCME guidelines
• Present and future
challenges for lagoon
systems
• Tundra wetlands exist
downstream of lago...
Question: do wetlands provide
treatment?
• Anecdotal evidence
• Answer hampered by
– Lack of knowledge
– Lack of standardi...
Carbon Interactions
DC = dissolved carbon
PC = particulate carbon
DIC = dissolved inorganic carbon
DOC = dissolved organic...
6
Principal components of the nitrogen cycle in wetlands (Docstoc,
2013)
7
Phosphorus cycling processes: Dissolved inorganic phosphorus (DIP); dissolved
organic phosphorus (DOP); particulate orga...
Question
How well do wetlands perform
in a cold climate?
8
Treatment Processes
9
Suspended Solids Phosphorus
sedimentation matrix sorption
filtration plant uptake
Nitrogen Soluble O...
Wetland Surveys 2009-2012
• Phase 1: Arctic Summer
• Phase 2: Rapid Assessment Protocol
• Phase 3: Data Analysis and Tool
...
Wetland Surveys
i. Arctic Summer (inlet, outlet)
– Seasonal trend
– No pretreatment or pretreatment (facultative
lakes or ...
12
0
50
100
150
200
250
300
350
Influent Effluent
Arviat, NunavutBOD5mg-L
Sampling Dates
13
0
5
10
15
20
25
30
35
40
45
Influent Effluent
Coral Habour, NunavutTotalAmmoniaNitrogenmg-L
Sampling Dates
14
Wetland Surveys
ii. Intensive Sampling
– Rapid, intensive testing (2-4 days)
– Sampling stations along transects
cBOD5 ...
15
Wetland Community cBOD5 cBOD5 % m3/d
Size (ha) Infl Effl Red 122 day summer
u.d. Baker Lake 466 6 99 500
17 Gjoa Haven ...
16
0
10
20
30
40
50
60
70
80
90
100
%FSS %VSS
Sample Location
PercentComposition
Composition of Total Suspended Solids
Pon...
17
0
10
20
30
40
50
60
70
80
90
100
%FSS %VSS
Sample Location
PercentComposition Composition of Total Suspended
Solids Ulu...
Predictive Tools
• Rules of thumb (sometimes also called scaling
factors)
• Regression equations and loading charts
• Simp...
Campbell and Ogden 1999
19
As
=
𝑄(ln𝐶𝑜−ln𝐶𝑒
) 𝐾𝑡 ∙𝑑 ∙𝑛
Where:
As = surface area of the wetland
Q = flow, in m3/day
Co = in...
Alberta Model 2000
20
A =
0.0365
𝑄
𝑥 𝑙𝑛
𝐶𝑖−𝐶∗
𝐶 𝑒−𝐶∗
𝑘
Where:
A = area (ha)
k = aerial rate constant @ 20°C, m/yr
Q = desi...
Comparison of 1st Order Kinetic
Model with SubWet 2.0
• Campbell & Ogden predicts that a BOD5
reduction from 205 to 11 mg ...
Predictive tools – SubWet 2.0
22
• 16 rate coefficients
• 25 differential equations
• Easily obtained input parameters
• A...
23
16 Rate Coefficients
Range 0.05-
2.0
% Derivation of Simulation from
Measured
24
Nunavut NTW
BOD5 Ammonium Total
Phosphorus
BOD5 Ammonium Total
Phosphorus
Arvi...
Calibration of Problematic Sites
for BOD5
25
Before Calibration After Calibration
Community Measured Simulated % Diff Simu...
26
Summary Report
• 380 pages
• Provides background
to studies
• Overview of wetlands
• Interpretation of the
data
• All r...
27
cawt.ca
SubWet published literature
Chouinard, A., Balch, G.B., Wootton, B.C., Jørgensen, S.E. and Anderson, B.C., 2014. Modelling...
29
Coral Harbour
Northern Wastewater Strategy
Hybridized approach (lagoons + wetlands)
Common Challenges
• Cold temperatures lower treatment rates in
lagoons
• Long HRT required
• Accumulation of sludge can de...
Wetlands Provide Additional
Treatment
However: Current Regulatory Challenges
• Wetlands considered “receiving
environment”...
32
• Designate wetlands as part of treatment
train (protect and preserve for future)
• SubWet and interpolated mapping ope...
SubWet as a Predictive
Management Tool
Scenarios:
• Need to decant early – what volume, conc can be
released before wetlan...
Concluding Remarks
• Wetlands do provide treatment benefit
• Sampling protocols and predictive tools
exist
• Consideration...
Concluding Remarks
• Demand for decentralized treatment likely
to increase
• Demand for specialized treatment to off-
load...
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Assessing the performance of cold climate natural wetlands in the treatment of domestic wastewater effluents in northern Canada

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Features background information about how treatment wetlands work, the SubWet program, and assessing arctic treatment wetlands.

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Assessing the performance of cold climate natural wetlands in the treatment of domestic wastewater effluents in northern Canada

  1. 1. Assessing the performance of cold climate natural wetlands in the treatment of domestic wastewater effluents in northern Canada Gordon Balch‡, Brent Wootton‡, Colin Yates†, Sven Jørgensen¥ and Annie Chouinard§ ‡Centre for Alternative Wastewater Treatment, Fleming College, Lindsay †Faculty of Environment, University of Waterloo, Waterloo ¥ Water Research Laboratories, ASP, Væløse, Denmark § Civil Engineering Queen’s University, Kingston
  2. 2. Focus • Wetlands are providing a treatment benefit • Assessment tools are available • Wetlands could be part of a hybridized wastewater treatment strategy 2
  3. 3. Background • CCME guidelines • Present and future challenges for lagoon systems • Tundra wetlands exist downstream of lagoons 3 Pond Inlet – sewage lagoon Paulatuk– sewage lagoon
  4. 4. Question: do wetlands provide treatment? • Anecdotal evidence • Answer hampered by – Lack of knowledge – Lack of standardized testing – Inability to predict response to changing conditions 4 Ulukhaktu k
  5. 5. Carbon Interactions DC = dissolved carbon PC = particulate carbon DIC = dissolved inorganic carbon DOC = dissolved organic carbon Kadlec & Wallace 2008
  6. 6. 6 Principal components of the nitrogen cycle in wetlands (Docstoc, 2013)
  7. 7. 7 Phosphorus cycling processes: Dissolved inorganic phosphorus (DIP); dissolved organic phosphorus (DOP); particulate organic phosphorus (POP); particulate inorganic phosphorus (PIP); inorganic phosphorus (IP) (Reddy, 2008)
  8. 8. Question How well do wetlands perform in a cold climate? 8
  9. 9. Treatment Processes 9 Suspended Solids Phosphorus sedimentation matrix sorption filtration plant uptake Nitrogen Soluble Organics ammonification aerobic microbial degradation nitrification anaerobic microbial degradation denitrification Pathogens plant uptake sedimentation matrix absorption filtration ammionia volatilization natural die-off Metals predation adsorption and cation exchange UV irradiation complexation and precipitation excretion of antibiotics from plant roots plant uptake microbial oxidation / reduction Temperature Dependent
  10. 10. Wetland Surveys 2009-2012 • Phase 1: Arctic Summer • Phase 2: Rapid Assessment Protocol • Phase 3: Data Analysis and Tool development 10
  11. 11. Wetland Surveys i. Arctic Summer (inlet, outlet) – Seasonal trend – No pretreatment or pretreatment (facultative lakes or lagoons) – Lagoon decants / exfiltration – Performance (BOD5, TAN, TSS, microbial, etc.) – Calibration of SubWet 2.0 rate coefficients for Northern conditions
  12. 12. 12 0 50 100 150 200 250 300 350 Influent Effluent Arviat, NunavutBOD5mg-L Sampling Dates
  13. 13. 13 0 5 10 15 20 25 30 35 40 45 Influent Effluent Coral Habour, NunavutTotalAmmoniaNitrogenmg-L Sampling Dates
  14. 14. 14 Wetland Surveys ii. Intensive Sampling – Rapid, intensive testing (2-4 days) – Sampling stations along transects cBOD5 TKN TAN TSS
  15. 15. 15 Wetland Community cBOD5 cBOD5 % m3/d Size (ha) Infl Effl Red 122 day summer u.d. Baker Lake 466 6 99 500 17 Gjoa Haven 133 2 98 356 10 Coral Harbour 181 14 92 287 9.5 Repulse Bay 385 25 93 197 7.8 Arviat 130 16 85 703 7.3 Ulukhatok 94 5 95 121 6.1 Taloyoak 80 25 69 257 5.0 Chesterfield Inlet 221 14 94 107 3.7 Whale Cove 40 21 47 245 2.1 Edzo 26 2 92 325 1.5 Paulatuk 40 2 95 102 0.87 Fort Providence 60 32 47 0.58 Pond Inlet 70 50 29 312 • Unusual (large) • No pre-treatment • Large vol, size • Pre-treatment • Large vol, size • Pre-treatment • Good Pre-Treat • Recalcitrant • Decant event • Small wetland • Small wetland • Large slope
  16. 16. 16 0 10 20 30 40 50 60 70 80 90 100 %FSS %VSS Sample Location PercentComposition Composition of Total Suspended Solids Pond Inlet 0 20 40 60 80 100 120 140 160 180 Influent Efflluent TSS
  17. 17. 17 0 10 20 30 40 50 60 70 80 90 100 %FSS %VSS Sample Location PercentComposition Composition of Total Suspended Solids Ulukhaktok 0 500 1000 1500 2000 2500 3000 Influent effluent TSS
  18. 18. Predictive Tools • Rules of thumb (sometimes also called scaling factors) • Regression equations and loading charts • Simple first order kinetic models (e.g., k – C* model) • Variable - order, mechanistic or compartmental models (e.g., SubWet 2.0) and sophisticated 2D and 3D models (e.g., HYDRUS, WASP, TABS-2, STELLA) 18
  19. 19. Campbell and Ogden 1999 19 As = 𝑄(ln𝐶𝑜−ln𝐶𝑒 ) 𝐾𝑡 ∙𝑑 ∙𝑛 Where: As = surface area of the wetland Q = flow, in m3/day Co = influent BOD (mg/L) Ce = effluent BOD (mg/L) Kt = temperature – dependent rate constant d = depth of bed medium n = porosity of bed medium Kt = K20 θ(T-20) Where: K20 = rate constant at 20°C Θ = theta, the temperature correction factor set at 1.06 T = temperature of the water in °C
  20. 20. Alberta Model 2000 20 A = 0.0365 𝑄 𝑥 𝑙𝑛 𝐶𝑖−𝐶∗ 𝐶 𝑒−𝐶∗ 𝑘 Where: A = area (ha) k = aerial rate constant @ 20°C, m/yr Q = design flow (m3/d) Ci = influent concentration (mg/L) Ce = effluent concentration (mg/L) C* = wetland background limit (mg/L)
  21. 21. Comparison of 1st Order Kinetic Model with SubWet 2.0 • Campbell & Ogden predicts that a BOD5 reduction from 205 to 11 mg L-1 can be accomplished in a wetland 0.25 hectares in size • The Chesterfield Inlet wetland can accomplish this level of treatment BUT wetland size is 5 hectares • Campbell & Ogden greatly over estimates treatment efficiency of wetland 21
  22. 22. Predictive tools – SubWet 2.0 22 • 16 rate coefficients • 25 differential equations • Easily obtained input parameters • Ability to calibrate to site conditions • Models BOD5, Ammonium, Organic Nitrogen, Nitrate and Total Phosphorus • Easy to use • Available as free-ware • Calibrated to 11 individual tundra treatment wetlands Nunavut: Arviat, Coral Harbour, Gjoa Haven, Pond Inlet, Repulse Bay, Whale Cove NTW: Edzo, Fort Providence, Paulatuk, Taloyoak, Ulukhaktuk
  23. 23. 23 16 Rate Coefficients Range 0.05- 2.0
  24. 24. % Derivation of Simulation from Measured 24 Nunavut NTW BOD5 Ammonium Total Phosphorus BOD5 Ammonium Total Phosphorus Arviat 18 7 2 Edzo 8 15 9 Coral Harbour 5 14 8 Fort Providence 79 57 56 Gjoa Haven 2 3 12 Paulatuk 30 10 1 Pond Inlet 5 4 4 Taloyoak 15 2 9 Repusle Bay 5 4 4 Ulukhaktuk 5 16 11 Whale Cove 64 10 34 • Provides the lagoon operator the ability to forecast how the wetland will respond • Forecast future capacities and needs
  25. 25. Calibration of Problematic Sites for BOD5 25 Before Calibration After Calibration Community Measured Simulated % Diff Simulated % Diff Whale Cove 21 8.6 64 21 0.5 Paulatuk 2 13 30 1.9 0.3 Fort Providence 32 9.8 79 34 6.4
  26. 26. 26 Summary Report • 380 pages • Provides background to studies • Overview of wetlands • Interpretation of the data • All raw data appended • Predictive tools • User manual for SubWet 2.0
  27. 27. 27 cawt.ca
  28. 28. SubWet published literature Chouinard, A., Balch, G.B., Wootton, B.C., Jørgensen, S.E. and Anderson, B.C., 2014. Modelling the performance of treatment wetlands in a cold climate. In Advances in the Ecological Modelling and Ecological Engineering applied on Lakes and Wetlands. 1st Edition. Jørgensen, S.E.; Chang, N.B.; Fuliu, X., Eds. Elsevier: Amsterdam, Netherlands Chouinard, A., Yates, C.N., Balch, G.C., Jørgensen, S.E., Wootton, B.C., Anderson, B.C., 2014. Management of Tundra Wastewater Treatment Wetlands within a Lagoon/Wetland Hybridized Treatment System Using the SubWet 2.0 Wetland Model. Water, 6(3):439-454 Yates, C. N., Wootton, B. C., and Murphy, S. D., 2012. Performance assessment of Arctic tundra municipal wastewater treatment wetlands through an Arctic summer. Ecological Engineering, 44(0), 160-173 Huang, J.J., Gao, X., Balch, G., Wootton, B., Jørgensen, S.E., Anderson, B. 2014. Modelling of vertical subsurface flow constructed wetlands for treatment of domestic sewage and stormwater runoff by subwet 2.0. Ecological Engineering 74:8-12. Huang, J.J., Gao, X., Balch, G., Wootton, B., Jørgensen, S.E., Anderson, B. 2014. submitted. The comparison of first-order model and dynamic model for the modelling of free water subsurface constructed wetlands: SubWet 2.0 and WASP 7.5. Jørgensen, S.E.; Gromiec, M.J. Mathematical models in biological waste water treatment—Chapter 7.6. In Fundamentals of Ecological Modelling, Volume 23, 4th Edition: Applications in Environmental Management and Research; Jørgensen, S.E., Fath, B.D., Eds.; Elsevier: Amsterdam, the Netherlands, 2011; pp. 1–414. Yates, C.N., Wootton, B.C., Jørgensen, S.E., Murphy, S.D., 2013. Wastewater Treatment: Wetlands Use in Arctic Regions. In Encyclopedia of Environmental Management. Taylor and Francis: New York Yates, C., Balch, G.B., Wootton, B.C., Jørgensen, S.E., 2014. Practical Aspects, Logistical Challenges, and Regulatory Considerations for Modeling and Managing Treatment Wetlands in the Canadian Arctic. In: Advances in the Ecological Modeling and Ecological Engineering applied on Lakes and Wetlands. 1st Edition. Jørgensen, S.E., Chang, N. B. and Fuliu, X., Eds. Elsevier, Amsterdam, The Netherlands, 560 pages Yates, C.N., Balch, G.C., Wootton, B.C., Jørgensen, S.E., 2014. Exploratory Performance Testing of a Pilot Scale HSSF wetland in the Canadian Arctic. In Advances in the Ecological Modelling and Ecological Engineering applied on Lakes and Wetlands. 1st Edition. Jørgensen, S.E.; Chang, N.B.; Fuliu, X., Eds. Elsevier: Amsterdam, Netherlands Yates, C.N., Balch, G.C., Wootton, B.C., Jørgensen, S.E., 2014. Framing the Need for Application of Ecological Engineering in Arctic Environments. In Advances in the Ecological Modelling and Ecological Engineering applied on Lakes and Wetlands. 1st Edition. Jørgensen, S.E.; Chang, N.B.; Fuliu, X., Eds. Elsevier: Amsterdam, Netherlands 28
  29. 29. 29 Coral Harbour Northern Wastewater Strategy Hybridized approach (lagoons + wetlands)
  30. 30. Common Challenges • Cold temperatures lower treatment rates in lagoons • Long HRT required • Accumulation of sludge can decrease lagoon’s design capacity • Population growth • Need to release effluent earlier than desired • Treatment targets not achieve 30
  31. 31. Wetlands Provide Additional Treatment However: Current Regulatory Challenges • Wetlands considered “receiving environment” • Until now, lack of proof in Wetland performance • Considered “black box”, no predictive ability • No point of control • How and what should be sampled, where to analyze (sample shelf life issues) 31
  32. 32. 32 • Designate wetlands as part of treatment train (protect and preserve for future) • SubWet and interpolated mapping open the “black box” • Survey protocols have been developed and proven to work Challenges can be overcome
  33. 33. SubWet as a Predictive Management Tool Scenarios: • Need to decant early – what volume, conc can be released before wetland treatment is overwhelmed • Decant practices (time of year, frequent/small volumes versus less frequent/larger volumes or exfiltration versus scheduled decants • SubWet to predict treatment capacity to meet future population growth • Applicable to industrial sites requiring domestic sewage treatment • Help regulators better predict treatment capacities of municipalities 33
  34. 34. Concluding Remarks • Wetlands do provide treatment benefit • Sampling protocols and predictive tools exist • Consideration of a hybridized approach should be considered 34
  35. 35. Concluding Remarks • Demand for decentralized treatment likely to increase • Demand for specialized treatment to off- load burden to centralized systems may increase • May see greater need for advanced treatment systems for Nitrate and Phosphorous in relationship to source water protection 35 Acknowledgements

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