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A new bioremediation technology to clean up per- and polyfluoroalkyl substances, or PFAS, chemical pollutants that threaten human health and ecosystem sustainability, has been developed by Texas A&M AgriLife researchers. The material has potential for commercial application for the removal of PFAS, also known as “eternal chemicals”.

Published on 28 July in Nature Communicationthe research was a collaboration of Susie Dai, Ph.D., associate professor in the Texas A&M Department of Plant Pathology and Microbiology, and Joshua Yuan, Ph.D., chair and professor at Washington University in St. Louis Department of Energy, environmental and chemical engineering, formerly in the Department of Plant Pathology and Microbiology at Texas A&M.

A grant from the National Institute of Environmental Health Sciences and support from Texas A&M AgriLife funded the work.

Eliminating PFAS contamination is a challenge

PFAS are used in many applications such as food wraps and packaging, dental floss, fire fighting foam, non-stick cookware, textiles and electronics. These days, PFAS are widely distributed into the environment from manufacturing or products containing the chemicals, Dai said.

But, according to the US Environmental Protection Agency, EPA, scientific studies show that at certain levels, some of these chemicals can be harmful to humans and wildlife. Health effects can include:

  • 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 certain cancers, including prostate, kidney and testicular cancers.
  • Reduced ability of the body’s immune system to fight infection, including reduced response to vaccination.
  • Interference with the body’s natural hormones.
  • Increased cholesterol levels and/or risk of obesity.

“PFAS do not degrade easily in the environment and are toxic even at minute concentrations,” Dai said. “They must be removed and destroyed to avoid human exposure and negative impacts on the ecosystem.

“PFAS are so stable because they are composed of a chain of carbon and fluorine atoms bonded together, and the carbon-fluorine bond is one of the strongest chemical bonds. They can occur in the water at a very low concentration and you have to concentrate them and then destroy them.”

The current way to destroy them is to burn them, an expensive multi-step process. Commercial products such as activated carbon are used as a cleaning material to adsorb PFAS compounds. The material is then sent for incineration.

Sustainable and inexpensive alternative

Dai and Yuan developed a technique of using a plant-derived material to adsorb PFAS and remove them with microbial fungi that literally eat the “eternal chemicals.”

“We produced sustainable plant material that could be used to concentrate PFAS chemicals,” Dai said.

“The plant cell wall material serves as a framework for adsorbing PFAS,” she said. “Then that material and the adsorbed chemical serve as food for a microbial fungus. The fungus eats it, it’s gone, and you don’t have a problem with elimination. Basically, the fungus does the detoxification process.”

It is a sustainable treatment system with powerful potential to remove harmful chemicals to protect human health and the ecosystem in a non-toxic and more cost-effective way, Dai said.

Potential business applications

The EPA has established a nationwide program to monitor the occurrence and levels of PFAS in public water systems and is considering adding PFAS thresholds to drinking water standards.

“While threshold levels are part of drinking water standards, municipal water treatment plants must comply with EPA regulations. Manufacturers will need to monitor these chemicals and remove them if necessary,” Dai said.

The innovative biomass remediation that Dai and Yuan have developed could help implement these changes more cost-effectively. The benefits of this technology go beyond drinking water standards.

“We live on a planet where every component interacts,” Dai said. “People are concerned not only about water, but also about local crops being produced using that water to feed animals that are part of the food supply.”