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Removal of Pathogenic Bacteria
Removal
of
by Wetlands
Pathogenic Bacteria
by Wetlands
Benjamin Tanner
Why Wetlands?
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Eco-friendly
No addition of chemicals
Natural attenuation
Habitat for birds
Look purdy
Pathogenic Bacteria:
What are They?
• Slow down….what’s a bacteria?
– Ubiquitous coinhabitants of this planet
– Degraders
– Can grow EXPLOSIVELY
• Pathogens can cause disease
– Typically are similar in terms of morphology
Where Do They Come From?
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Toilets, mainly
Zoonotic sources
Insect vectors
Occasionally, things like soil and water
Pathogenic Bacteria
Their Baggage
Pathogenic Bacteria
Their Baggage
Enteric Pathogens and
Pathogenesis
PATHOGEN
EFFECT
Toxigenic E. coli
HUS/ (Bloody) Diarrhea
Shigella spp.
HUS/ profuse GI illness and person
to person transmission
Camplyobacter jejuni
Symptoms of “food poisoning”
Toxigenic Cholera
Often fatal GI illness
Salmonella spp.
Nausea, cramps, diarrhea
Staphylococcus aureus
Skin infection
Mechanisms of
Inactivation/Removal
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Sedimentation (gravity)
Competition/Biotic stresses
Predation (protozoan grazers)
Adsorption
U.V. light
Does it Work?
• Approximate 2 log (99%)
reduction in bacterial pathogens
• Retention time is key
• Subsurface vs. surface wetland
– U.V
– Aesthetic appeal
– Insect vector control
Some Problems
• Migratory birds
– Salmonella, Campylobacter
• Dairy Wastewater Treatment
– Potentially concentrates a NASTY
pathogen (O157:H7) from cattle
• Groundwater Leaching