Filtration Media for In-Home PFAS Removal from Drinking Water - Summary Abstract
Per- and polyfluoroalkyl substances (PFAS), also commonly known as perfluorinated compounds, are a large family of
man-made, globally distributed chemicals that have been used for decades. Perfluorooctanoic acid (PFOA) and
perfluorooctane sulfonate (PFOS) are the most common PFAS, but thousands of other derivatives exist. PFAS have been
widely used in consumer products such as non-stick cookware (Teflon®), carpets and carpet treatment products
(Scotchgard®), food packaging, aqueous firefighting foams, hydraulic aviation fuels and in the aerospace, automotive,
construction, and electronics industries. PFAS are emerging environmental pollutants in groundwater, and they are attracting
significant attention due to their global distribution, persistence, toxicity and tendency to bio-accumulate. PFAS
contamination has been found in more than 1400 locations in 49 states and the EPA estimates that the drinking water of
more than 110 million Americans may already be contaminated. Once released into the environment, they are not easily
broken down by air, water, or sunlight. Thus, people can be exposed to PFAS that were manufactured months or years in
the past. PFAS can travel long distances in the air and water, exposing people to PFAS manufactured or emitted from
facilities many miles away. Human exposure can also occur through contact with products containing PFAS. In 2016, EPA
established a lifetime health advisory (LHA) level of 70 parts per trillion (ppt) for individual or combined concentrations of
PFAS in drinking water and many states are establishing even lower levels. Epidemiological studies have shown that the
occurrence of PFAS in humans is probably linked to a high incidence of thyroid disease, high cholesterol, ulcerative colitis,
kidney cancer, testicular cancer, and pregnancy-induced hypertension. Current water treatment technologies that can meet
the EPA targets are not cost effective, especially for in-home use, necessitating a need for technology/advanced materials
to cleanup drinking water that are efficient, cost effective and can meet the EPA target of 70 ppt or lower.
TDA Research, Inc (TDA) proposes to develop an adsorption-based system for removing PFAS from drinking
water down to EPA prescribed limits of 70 ppt (parts per trillion) or lower. The key to such a system is a low cost, high
capacity adsorbent with fast kinetics to remove PFAS. TDA’s sorbent uses a mesoporous carbon structure grafted with
Lewis base functionalized groups to remove PFAS via physical adsorption. The mesopores provides very fast adsorption
kinetics and accessibility to the functionalized adsorption sites. The strength of the Lewis acid-base interaction can be tuned
to allow the sorbent to be effective even in the presence of the multiple contaminants found in drinking water. The fast
adsorption and high PFAS capacity of the sorbent will reduce the system size and enable their use in smaller home-based
systems.
