EFFICACY OF A HYBRID SUBSURFACE FLOW CONSTRUCTED WETLAND FOR THE

TREATMENT OF AQUACULTURE WASTEWATER

A. Snow, B.C. Anderson, B. Wootton and A. Hellebust

44th

Central Canadian Symposium on Water Quality Research

Burlington, ONFebruary 24, 2009

OUTLINEOUTLINE

• Aquaculture and aquaculture wastewater

• Constructed wetlands

• Haliburton Hatchery Outdoor Association’s (HHOA) fish hatchery

• HHOA’s hybrid subsurface flow constructed wetland (SSFCW)

AQUACULTUREAQUACULTURE

• Farming of fish, shellfish and aquatic plants in fresh, brackish

or

marine environments

AQUACULTURE GROWTHAQUACULTURE GROWTH

Average growth of the aquaculture industry compared to capture fisheries and terrestrial farmed meat production since 1970 (FAO, 2007)

AQUACULTURE WASTEWATERAQUACULTURE WASTEWATER

1.

Low waste concentrations

• Solids (organic and inorganic)

• Nutrients (dissolved and particulate nitrogen and phosphorus)

Parameter Units Municipal WW Trout Farm EffluentBOD5 mg/L 220 15TSS mg/L 220 12NH4 mg N/L 25 1.3TP mg P/L 8 0.29

A comparison of municipal wastewater and trout farm effluent

AQUACULTURE WASTEWATERAQUACULTURE WASTEWATER

2.

High flow rates

Facility Effluent Flow (L/s)Large salmon flow through 2625Medium striped bass flow through 76.5Medium tilapia flow through 170Large tilapia flow through 631.5Medium trout flow through 133Large trout flow through 1337Large striped bass recirculating 2.8Large tilapia recirculating 1.4

Effluent flow rates from model aquaculture facilities in the United States

WASTEWATER TREATMENTWASTEWATER TREATMENT

• Aquaculture facilities can generate significant mass loadings of

pollutants

FacilityBOD5 TSS NH4 TP(kg/yr) (kg/yr) (kg/yr) (kg/yr)

Large trout flow through 632 455 505 964 54 813 12 227

Mass loading of pollutants from a model trout flow through facility

• Municipal wastewater treatment technologies → aquaculture effluents

• Aquaculture industry requires a simple, low cost effluent treatment technology

• Constructed wetlands

WETLANDSWETLANDS

• Ecosystems that are distinguished by the presence of:• water either at the surface or within the root zone for a sufficient

amount of time each year in order to maintain saturated soil conditions

• aquatic vegetation

• Functions of natural wetlands:• Provide habitat, food and water for wildlife• Control flood heights• Recharge ground water supplies• Contribute to recreational activities and regional economies• Improve water quality

CONSTRUCTED WETLANDSCONSTRUCTED WETLANDS

• A man-made system that is designed to utilize the natural processes involving vegetation, soils and microbial communities for the purpose of wastewater treatment

• Basin• Natural/synthetic liner• Substrate• Structures to control the amount of water entering and exiting

the system• Populations of aquatic invertebrates and microorganisms• Aquatic vegetation

CONSTRUCTED WETLAND CONSTRUCTED WETLAND CLASSIFICATION CLASSIFICATION

CONSTRUCTED WETLAND

SURFACE FLOW

SUBSURFACE FLOW

VERTICAL FLOW

HORIZONTAL FLOW

HYBRID SYSTEM

SURFACE FLOW SURFACE FLOW

VERTICAL FLOWVERTICAL FLOW

HORIZONTAL FLOWHORIZONTAL FLOW

TREATMENT MECHANISMSTREATMENT MECHANISMS

Pollutant Mechanism

BOD• Sedimentation• Filtration• Aerobic & anaerobic decomposition

TSS• Sedimentation• Filtration

Phosphorus• Adsorption• Precipitation

Nitrogen • Nitrification-denitrification

Pathogens

• Sedimentation• Filtration• Predation• Natural die-off

HHOAHHOA’’S FISH HATCHERYS FISH HATCHERY

HHOAHHOA’’S HYBRID SSFCWS HYBRID SSFCW

FRAME AND LINERFRAME AND LINER

GRAVEL AND SAND LAYERSGRAVEL AND SAND LAYERS

FILTER SAND INSTALLEDFILTER SAND INSTALLED

HHOAHHOA’’S HYBRID SSFCWS HYBRID SSFCW

OBJECTIVESOBJECTIVES

• Investigate the ability of the hybrid SSFCW to treat effluent from the hatchery under cold climate conditions

• Assess the treatment of conventional water quality parameters• Assess the effectiveness of phosphorus removal by a slag filter• Investigate the removal of fish pathogens common to land

based cold-water aquaculture facilities• Assess the ability of the wetland to remove commonly used

aquaculture antibiotics• Determine how antibiotics affect treatment wetland

performance and microbial populations

cBODcBOD55 RESULTSRESULTS

DO RESULTSDO RESULTS

NHNH33 --N RESULTSN RESULTS

CONCLUSIONSCONCLUSIONS

• Rapid growth of the aquaculture industry

• Require simple, low cost effluent treatment technology

• Constructed wetlands

• Treat a concentrated portion of the effluent

• Over a 3 year period, we will be assessing the ability of an

innovative hybrid SSFCW to treat aquaculture wastewater from

the Haliburton

fish hatchery

ACKNOWLEDGEMENTSACKNOWLEDGEMENTS

Aqua Treatment TechnologiesAquaculture Collaborative Research and Development Program, DFO CAWT, Fleming CollegeCounty of HaliburtonEnvironment Haliburton!Essroc

CementHaliburton

County Development CorporationHaliburton

Hatchery Outdoor AssociationHaliburton

Highlands Secondary School Haliburton

Highlands Stewardship CouncilHeatline

Ministry of Natural Resources -

MindenMunicipality of Dysart et al.New Directions Research Program, OMAFRANSERCOntario Fishery Enhancement and Aquaculture AssociationOntario Trillium FoundationQueen’s University.Rivercourt

Engineering IncTrent UniversityU-Links Community Based EducationWilfred Laurier University