EFFICACY OF A HYBRID SUBSURFACE FLOW CONSTRUCTED WETLAND FOR THE TREATMENT OF AQUACULTURE WASTEWATER A. Snow, B.C. Anderson, B. Wootton and A. Hellebust 44 th Central Canadian Symposium on Water Quality Research Burlington, ON February 24, 2009
OUTLINE Aquaculture and aquaculture wastewater Constructed wetlands Haliburton Hatchery Outdoor Association s (HHOA) fish hatchery HHOA s hybrid subsurface flow constructed wetland (SSFCW)
AQUACULTURE Farming of fish, shellfish and aquatic plants in fresh, brackish or marine environments
AQUACULTURE GROWTH Average growth of the aquaculture industry compared to capture fisheries and terrestrial farmed meat production since 1970 (FAO, 2007)
AQUACULTURE WASTEWATER 1. Low waste concentrations Solids (organic and inorganic) Nutrients (dissolved and particulate nitrogen and phosphorus) A comparison of municipal wastewater and trout farm effluent Parameter Units Municipal WW Trout Farm Effluent BOD 5 mg/l 220 15 TSS mg/l 220 12 NH 4 mg N/L 25 1.3 TP mg P/L 8 0.29
AQUACULTURE WASTEWATER 2. High flow rates Effluent flow rates from model aquaculture facilities in the United States Facility Effluent Flow (L/s) Large salmon flow through 2625 Medium striped bass flow through 76.5 Medium tilapia flow through 170 Large tilapia flow through 631.5 Medium trout flow through 133 Large trout flow through 1337 Large striped bass recirculating 2.8 Large tilapia recirculating 1.4
WASTEWATER TREATMENT Aquaculture facilities can generate significant mass loadings of pollutants Mass loading of pollutants from a model trout flow through facility Facility Large trout flow through BOD 5 TSS NH 4 TP (kg/yr) (kg/yr) (kg/yr) (kg/yr) 632 455 505 964 54 813 12 227 Municipal wastewater treatment technologies aquaculture effluents Aquaculture industry requires a simple, low cost effluent treatment technology Constructed wetlands
WETLANDS 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 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 CLASSIFICATION CONSTRUCTED WETLAND SURFACE FLOW SUBSURFACE FLOW VERTICAL FLOW HORIZONTAL FLOW HYBRID SYSTEM
SURFACE FLOW
VERTICAL FLOW
HORIZONTAL FLOW
TREATMENT MECHANISMS Pollutant BOD TSS Phosphorus Nitrogen Pathogens Mechanism Sedimentation Filtration Aerobic & anaerobic decomposition Sedimentation Filtration Adsorption Precipitation Nitrification-denitrification Sedimentation Filtration Predation Natural die-off
HHOA S S FISH HATCHERY
HHOA S S HYBRID SSFCW
FRAME AND LINER
GRAVEL AND SAND LAYERS
FILTER SAND INSTALLED
HHOA S S HYBRID SSFCW
OBJECTIVES 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
cbod 5 RESULTS
DO RESULTS
NH 3 -N N RESULTS
CONCLUSIONS 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
ACKNOWLEDGEMENTS Aqua Treatment Technologies Aquaculture Collaborative Research and Development Program, DFO CAWT, Fleming College County of Haliburton Environment Haliburton! Essroc Cement Haliburton County Development Corporation Haliburton Hatchery Outdoor Association Haliburton Highlands Secondary School Haliburton Highlands Stewardship Council Heatline Ministry of Natural Resources - Minden Municipality of Dysart et al. New Directions Research Program, OMAFRA NSERC Ontario Fishery Enhancement and Aquaculture Association Ontario Trillium Foundation Queen s University. Rivercourt Engineering Inc Trent University U-Links Community Based Education Wilfred Laurier University