What is PFAS?
PFAS is the common term used for both per-fluoroalkyl and poly-fluoroalkyl compounds – thousands of man-made chemicals that have been in production since the 1950s.
The common feature all PFAS compounds have in common is that some, or all, of the links between the hydrogen atoms and carbon chain are replaced by fluorine atoms. These carbon-fluorine bonds are very strong making PFAS resistant to chemical, thermal and biological degradation.
When it is applied to products, PFAS makes them water, oil and stain resistant. It can also increase chemical and thermal stability, and reduce friction. This is why PFAS is used to manufacture many items including waterproof and stain-resistant coatings for textiles, paper and cardboard, metal plating paints, pesticides, greaseproof paper, cosmetics, lubricants, and fire-fighting foams.
What makes PFAS dangerous?
The properties that make PFAS compounds so useful are the very reason it is dangerous to the environment and humans. PFAS compounds do not easily break down or dissipate and have been detectable in the bloodstream for years after someone is exposed to the chemicals.
The United Stated Environmental Protection Agency has noted that:
“Current peer-reviewed scientific studies have shown that exposure to certain levels of PFAS may lead to:
- Reproductive effects such as decreased fertility or increased high blood pressure in pregnant women.
- Developmental effects or delays in children, including low birth weight, accelerated puberty, bone variations, or behavioral changes.
- Increased risk of some cancers, including prostate, kidney, and testicular cancers.
- Reduced ability of the body’s immune system to fight infections, including reduced vaccine response.
- Interference with the body’s natural hormones.
- Increased cholesterol levels and/or risk of obesity.”
Humans are not the only living things affected by PFAS contamination. Researchers have discovered the bio-accumulation of PFAS compounds in fish and in plants growing near contaminated sites. While PFAS impacted waterways ‘look healthy’, with fish, aquatic organisms and bird populations present in abundance, the long-term and intergenerational effects are a cause for alarm.
Where does PFAS in our environment come from?
Over the past two decades, there has been growing awareness and concern about the persistent and bio-accumulative nature of PFAS compounds; in particular perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA).
PFOS and PFOA were widely used in firefighting foams and stain and water-resistant products and have subsequently been detected in soil, sediment, surface water and groundwater, as well is in plant and animal tissue around the world. This is due to:
- Direct use of products, such as the application of fire-fighting foams
- Accidental release of fugitive emissions, such as exhaust gases from sites where PFAS containing products are used or processed
- Contamination of wastewater, stormwater, or groundwater in part due to the improper disposal of solid wastes, sludges, or liquids
- Breakdown and leaching of products containing PFAS compounds while they are being manufactured or are in use in the environment
- Transfer of PFAS containing substances to landfills or wastewater drinking plants from the public and industry
- Leaching from waste disposal points, chemical storage, or landfill into the environment.
The persistent nature of the chemicals means even if regulations are introduced to limit the use of PFAS substances in manufacturing, there are significant challenges in the management of legacy wastes and products.
What are some of the technologies that exist to remove PFAS?
The main focus for PFAS removal has been the treatment of contaminated drinking water, water and soil effected by firefighting systems, concentrates and groundwater. Unfortunately, most of these methods are too expensive or inefficient to be used to treat the high-volume low concentration scenario of wastewater, or the high concentration and high level of co-contamination present in landfill leachate.
The LEEF System® combines a multiple step foam fractionation, to remove regulated PFAS contaminants to the limit of detection, while concentrating them into a very small volume. An optional solar distilling system, will further reduce the concentrate volume.
The LEEF System® is modular in design so can be implemented for any scale of application. It requires minimal energy and minimises the need for chemical additives, consumables or excessive waste transport.