Maybe PFAS clean-up is possible
National Institute of Environmental Health Sciences (nih.gov)
An innovative technology, developed with funding from the NIEHS Superfund Research Program, successfully removes PFAS from water. The technology has been adapted to a variety of applications, including tabletop filters, whole-house water filtration systems, and large-scale cleanup projects.
The Problem
PFAS are a
group of nearly 15,000 human-made chemicals used
for decades in a variety of industrial and consumer products, such as
firefighting foam and food packaging. Due to chemical bonds within the
molecules that are hard to split, PFAS resist natural degradation and can
accumulate in ecosystems and organisms, exposing people through drinking water,
food, and dust. The chemicals have been linked to a variety of health effects,
including changes in immune and liver function, obesity, diabetes, certain
cancers, and lower birth weights.
Current
technologies used to remove contaminants from water, such as activated carbon
and ion exchange treatments, do not work well for some PFAS. These approaches
also have low molecular selectivity — meaning that they are less effective when
other substances besides PFAS are present, which is often the case for
contaminated drinking water systems.
SRP Solutions
Funded by
an SRP small business innovation research grant,
Cyclopure, Inc., developed a sustainable technology to bind and remove PFAS
from drinking water. Their technology is made of cup-shaped cyclodextrins —
sugar molecules bound together in small rings — derived from corn starch. At
less than a nanometer across, the cyclodextrin cup can rapidly bind and trap a
variety of PFAS compounds faster and more efficiently than other filtration
materials.
The
technology can remove all 40 PFAS targeted in the U.S. Environmental Protection
Agency (EPA) PFAS Roadmap and
is certified by the National Sanitation Foundation International (NSF)
as safe for drinking water treatment.
After cyclodextrins trap PFAS molecules, the contaminants can be separated from the cyclodextrins in the laboratory, where the waste is concentrated for safe handling and disposal by destruction technologies without recontamination of the environment. During separation of PFAS waste, the technology undergoes regeneration, allowing reuse of the adsorbent for additional water filtration activities.
In 2022, SRP
provided Cyclopure with additional funding to use their technology in
developing products that detect PFAS and remove them from water. The new grant
allowed the team to pursue PFAS removal solutions for consumer and municipal
applications.
Testing
Water for PFAS
 |
| The water test kit includes a collection cup with a filter disc between two glass microfiber filters. (Image courtesy of Cyclopure) |
Cyclopure developed a kit to test water for PFAS. The kit is listed by NIEHS as a Sensor Technology for the 21st Century.
Their water test kit uses a collection cup with a filter paper made with cyclodextrins that traps PFAS as water flows through it. After collecting a sample, the user returns the kit to the company’s laboratory, where it is analyzed for 55 different PFAS compounds.
According to Cyclopure, their approach is more
cost-effective than currently available technologies and more convenient
because the user does not need to ship water samples. Users are sent a detailed
report about their sample, including concentrations of each PFAS detected and
location-relevant information, such as state drinking water regulations.
The water
test kits have been used to test tap water, rivers, lakes, and streams by
consumers, government agencies, research institutions, and environmental groups
across the U.S. and abroad. The Colorado Department of Public Health and
Environment is using the test kit as part of a program to test the water of
residents who rely on private wells for drinking water. The test kits have also
been used in Japan, the Netherlands, and Bangladesh.
Treating
Home Drinking Water
 |
| Each cartridge comes with a prepaid label to return the filter to the lab where the contaminants are safely disposed, and the filters are recycled. (Image courtesy of Cyclopure) |
Families
across the U.S. are using the filter cartridges to prevent PFAS exposures from
drinking water. Municipalities, including communities in Colorado, have
purchased cartridges to provide safe drinking water to households as an interim
solution while they prepare for large-scale water treatment systems.
The company also developed whole-home filter tanks that connect to residential water systems to remove PFAS from tap water throughout the home.
Because not every
consumer can install a whole-home water filtration system, such as those who
rent, an under-the-sink filter that would be more convenient to install and
less costly than the whole-home filters is under development.
Large-Scale
Water Treatment
The
PFAS-removal capacity of cyclodextrins in large-scale applications is
demonstrated through pilot installations across the U.S. These pilots have led
to commercial installations to clean up PFAS-contaminated water in:
- Municipal drinking water plants
- Landfills
- Groundwater
- Industrial wastewater
In 2024, the Massachusetts Department of Environmental Protection approved the use of the company’s cyclodextrins to remove PFAS from drinking water systems throughout the state. This approval followed 12 months of pilot testing in Newburyport and Lynnfield, Massachusetts, that successfully demonstrated reduction of PFAS in water to nondetectable levels throughout the study period.
Additional pilot testing is ongoing at municipal drinking water plants in Maryland, Alabama, and Nevada, with additional installations slated for New Hampshire, Pennsylvania, Georgia, and North Carolina. The company will install a full-scale treatment system in Alaska at the beginning of August 2024.
Also in
2024, Cyclopure began a pilot study to treat contaminated groundwater with PFAS
at the Willow Grove Naval Air Station in
Pennsylvania. The team installed a full-scale treatment system at another
Department of Defense site in the state, the Biddle Air National Guard Base.
The company
has been working with landfill operators in Michigan and Pennsylvania to
demonstrate removal of PFAS from landfill leachate. Landfill leachate forms
when rainwater filters through wastes placed in a landfill and often contains
high concentrations of PFAS leaching from different household goods.
The
technology is also being used to remove PFAS from industrial waste streams,
with full-scale treatment systems operating at a metal plating plant and
petroleum facility.
Lowering
Treatment Costs
In a
year-long pilot test to remove PFAS from wastewater at a metal plating plant in
Michigan, Cyclopure demonstrated that their technology requires less material
to clean up water than currently used water treatment methods. Compared to the
plant’s approach that used 180,000 pounds of activated carbon, Cyclopure was
able to accomplish similar performance using 21,000 pounds of cyclodextrins.
“We hope that our technology can help lower the cost of water treatment efforts and boost sustainability, preventing PFAS exposures and ultimately protecting human health,” said Cyclopure chief executive officer Frank Cassou.
