Cyanotoxins can be removed from drinking water. The problem is that currently available treatments may only treat specific toxins or only a limited amount of the toxin. It is important to know which toxins cannot be removed by the available treatment. Also, an operator should know how to optimize the available treatment to be able to remove as much toxin as possible. EPA has a summary of different treatment considerations when dealing with toxin removal (Summary of Cyanotoxins Treatments in Drinking Water). | |
| Treatment | Ability | | Membrane |
- More research is being done to better understand performance in removing cyanobacterial cells and toxins.
- Current research indicates nanofiltration is effective in removing extracellular microcystins.
- Reverse osmosis is effective in removing microcystins and cylindrospermopsin.
| | Potassium Permanganate |
- It is effective in treating against microcystins and anatoxins.
- It is not effective against saxitoxin.
- Further research is needed on the treatment for cylindrospermopsin.
| | Ozone |
- It is effective against microcystins, anatoxin-a, and cylindrospermopsin.
- It is not effective against saxitoxin.
| | Chloramines | - It is not effective against most common cyanotoxins.
| | Chlorine Dioxide | - It is not an effective treatment against cyanotoxins.
| | Free Chlorine | - It is effective against microcystin if the pH is less than 8. It is effective against cylindrospermopsin and saxitoxin. It is not effective against anatoxin-a.
| | Ultraviolet (UV) Radiation |
- It is not an effective treatment against cyanotoxins by itself.
- If added to either ozone or hydrogen peroxide to create advanced oxidation, they are effective against anatoxin-a and cylindrospermopsin.
- If UV dosage can be produced at very high levels and combined with ozone or hydrogen peroxide, then it may be able to treat for microcystins.
| | Powdered Activated Carbon Adsorption |
- Wood-based activated carbons are effective at adsorbing microcystin.
- Dosage may have to be as high as 20 mg/L for complete removal.
- Adsorption capability will vary based on type of carbon, pore size, type of cyanotoxin, and various water quality parameters like natural organic matter.
- More research is needed on effectiveness for cylindrospermopsin, anatoxin-a, and saxitoxin.
| | Granulated Activated Carbon Adsorption |
- It is effective in removing microcystins.
- Adsorption capability will vary based on type of carbon, pore size, type of cyanotoxin, and various water quality parameters like natural organic matter.
- It may need to be regenerated more often to ensure adsorption capacity remains sufficient.
- More research is needed on effectiveness for cylindrospermopsin, anatoxin-a, and saxitoxin, but current studies are indicating it will be effective.
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- What are the most common cyanotoxins?
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Regional HAB Advisory News | |
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For Idaho see the new Recreational Water Health Advisory website for updates.
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Idaho – CJ Strike Reservoir (Bruneau Arm, Snake River) Microcystin present; Hells Canyon Reservoir (Big Bar, Snake River) – Microcystin and Anatoxin-a present; Brownlee Reservoir (Snake River) – Microcystin present; Fernan Lake – Microcystins present, Morton Slough (near Pend Oreille Lake), Avondale Lake; Spirit Lake, Lake Cocolalla
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Oregon – South Umpqua River, Klamath Lake, Willamette River and Cove
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Washington – Anderson Lake, Wiser Lake, Silver Lake, Pattison Lake, Rufus Woods Lake, Lake Roosevelt, Long Lake, Scootney Reservoir, Round Lake, Sagemoor Pond, Pass Lake, Vancouver Lake, and Lake Campbell
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