Constructed Wetlands and Wastewater Treatment

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Constructed Wetlands and Wastewater Treatment

• Scott Stine
• SWES 574

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Types of Constructed Wetlands

• Surface Flow Wetlands (SF)
• similar to natural wetlands
• free floating, emergent, and submerged plants are
  used
• Subsurface Flow Wetlands (SSF)
• water flows below surface of support media
• emergent plants that are tolerant of water
  saturated soils are used

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Wastewater Treatment Uses

• Additional Secondary Treatment
• Tertiary Treatment
• Onsite Wastewater Treatment
• alternative to municipal sewage treatment
• used in animal feeding operations

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Microorganisms

• Bacteria
• Coliforms, Enterococci, C. perfringens
• Viruses
• Coliphage
• Parasites
• Cryptosporidium, Giardia

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Removal Processes

• Most processes are enhanced by vegetation
• Processes include
• Filtration
• Adsorption
• Predation
• UV light
• Sedimentation

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SSF vs. SF

• What are the objectives of the constructed
  wetland?
• Some considerations
• SSF remove pathogens more efficiently than SF
• SF allow more biodiversity and habitats
• SSF minimize pests such as mosquitoes

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Concerns

• Some bacteria are able to reproduce on some plant
  surfaces
• Enterococci
• Spore forming pathogens may be released by
  precipitation
• Cryptosporidium
• Giardia

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