Transcript Engineered Wetlands and Applications

Treatment Wetlands
Presented by:
Scott Wallace, P.E.
[email protected]
(612) 802-2329
References for Wetland Design
Water Environment Research
Foundation (WERF)
• Small Scale Constructed Wetland
Systems (Wallace & Knight,
2006)
Treatment Wetlands 2nd Edition
• (Kadlec & Wallace, 2009)
Types of Treatment Wetlands
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Surface Flow (SF)
Horizontal Subsurface Flow (HSSF)
Vertical Flow (VF)
Sludge Dewatering Reed Beds
Intensified Wetlands
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Aerated (cold climates)
fill-and-drain (warm climates)
reactive media (ammonia, phosphorus, etc)
industrial wastewaters
Surface Flow Wetlands
Kadlec & Wallace, 2008
Surface Flow Wetlands
Champion Paper, Pensacola Florida
Horizontal Subsurface Flow
Wetlands
Wallace & Knight, 2006
Horizontal Subsurface Flow
Wetland
Wildflower Meadows: 90-person treatment system
Vertical Flow Wetland
IWA, 2000
Vertical Flow Wetland
Rousillon, France
Sludge Dewatering Reed Bed
Skovby, Denmark: 8000-person treatment wetland
Kadlec & Wallace, 2008
Main Treatment Mechanisms
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Adsorption of dissolved-phase hydrocarbons
Microbial degradation of organic compounds
Settling of particulate compounds
Oxidation and reduction of nitrogen
compounds
• Precipitation of metals
• Use of intensification methods (aeration and
reactive medias to accelerate treatment)
Natural vs. Mechanical Systems
LEAST
Natural Systems
MOST
Energy and O&M Needs
MOST
Intensified
Wetlands
Mechanical
Treatment
Systems
Area Requirements
LEAST
Climate Range of
Treatment Wetlands
Wellsville, New York
Northern Sahara,
Libya
Casper, Wyoming
Casper
BP – Casper, Wyoming Refinery
• Operated 1912 to 1991
• 37,000 m3 of LNAPL recovered to date
• Extensive smear zone due to river flooding
• 50 to 100 years to remediate site
• High mountain west: -35oC
BP – Casper Wyoming Refinery
Casper Reuse Plan
HSSF Wetlands
SF Wetlands
Full-Size System from Pilot Data
Wallace & Kadlec, 2005
Casper Intensified Wetland Cell
Casper System Construction
Casper Wetland Construction
Casper Benzene Data 2004 - 2006
Benzene effluent at Outfall 001
consistently below detection levels
<0.01 mg/L
Rosebel Gold Mine
Project
Site
Cyanide Removal
Cyanide Levels from Reclaim to TWSP
1.00
0.90
0.80
Cyanide (mg/L)
0.70
0.60
0.50
Reclaim Cyanide
TWSP Cyanide
0.40
Permit WAD Cyanide
0.30
0.20
0.10
0.00
S-05
M-06
O-06
A-07
N-07
J-08
D-08
Month-Year
J-09
J-10
A-10
F-11
Iron Removal
Iron Levels from Reclaim to TWSP
7.00
6.00
Iron (mg/L)
5.00
4.00
Reclaim Iron
TWSP Iron
3.00
Permit Iron
2.00
1.00
0.00
S-05
M-06
O-06
A-07
N-07
J-08
Month-Year
D-08
J-09
J-10
A-10
F-11
Multi-Stage Treatment Processes
• Wetlands are typically multi-stage
treatment systems
– Process Chemistry
– Site Topography
Compania Minera
Antamina, Peru
Conclusions
• Treatment wetlands are already being used
in North America, South America, Europe,
Asia and Australia
• Surface flow, horizontal subsurface flow,
vertical flow, and intensified wetlands are all
being used
• Use of wetlands for treatment wetlands is
increasing on two major fronts:
– Range of applications in different industries
– Construction of wetlands in different geographic
regions
Treatment Wetlands
Thank you for your time