Read the full article by Emily Dieckman (University of Arizona News)

“University of Arizona and Northern Arizona University researchers are developing specialized, reusable sponges to remove a group of chemicals known as PFAS from water. The team, led by chemical and environmental engineering assistant professor Vicky Karanikola, has received $1.487 million from the Arizona Board of Regents, with $1.24 million allocated to UArizona.

PFAS is an abbreviation for perfluoroalkyl and polyfluoroalkyl substances, which are long-lasting manufactured chemicals that are resistant to water, heat and grease. They have been used for decades in products such as makeup, food packaging, nonstick pans, raincoats, carpeting and firefighting foam. But scientists now know exposure to PFAS can be harmful to humans and animals. Health effects include decreased fertility, developmental delays in children and increased risk of some forms of cancer.

The durability of PFAS – the same quality that makes them useful for many applications – means it is very difficult to remove them from the environment, and the chemicals have spread into water sources in areas throughout the world, including Tucson. Removal is an ongoing process. For instance, in a separate effort, the Central Tucson PFAS Project was launched in early 2022 to remove PFAS pollution from groundwater near Davis-Monthan Air Force Base.

Many sponges are made of cellulose, an abundant organic compound found in plants and used to make materials such as paper and textiles. To draw PFAS out of water, engineers need to use a material that can adsorb PFAS – or, more simply, a material that PFAS will stick to. This part is easy, as PFAS stick to many materials, including cellulose, naturally. The team even has to use polypropylene containers for all of its experiments because PFAS stick to glass.

While simple cellulose sponges are good for initial study of factors such as optimal pore size and density, sponges being developed for removal of PFAS are far more complex. They will soak up PFAS-contaminated water, then squeeze out clean water while the PFAS stay stuck. Then, an extraction solution will remove the PFAS from the sponges so they can be used again.” …