Texas A&M AgriLife researchers have developed a new bioremediation technology to clean up per- and polyfluoroalkyl substances, or PFAS, chemical pollutants that threaten human health and ecosystem sustainability. The material has the potential for commercial applications to dispose of PFAS, also known as “permanent chemicals.”
Published on July 28 in Communications of natureThe research was conducted in collaboration with Susie Dai, Ph.D., assistant professor in the Department of Plant Pathology and Microbiology at Texas A&M, and Joshua Yuan, Ph.D., chair and professor of the Department of Energy at Washington University in St. Louis. , environmental and chemical engineering, was formerly with Texas A&M’s Department of Plant Pathology and Microbiology.
A grant from the National Institute of Environmental Health Sciences and support from Texas A&M AgriLife funded the work.
Removing PFAS contamination is a difficult task
PFAS are used in many applications, such as food wrappers and packaging, dental floss, firefighting foam, nonstick cookware, textiles, and electronics. These days, PFAS are widely distributed in the environment as a result of manufacturing or from products that contain the chemical, Dye 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 may include:
- Reproductive effects such as reduced fertility or increased high blood pressure in pregnant women.
- Developmental effects or delays in children, including low birth weight, accelerated puberty, bone changes, or behavioral changes.
- Increased risk of certain cancers, including prostate, kidney, and testicular cancer.
- A decrease in the body’s immune system’s ability to fight infections, including a decrease in vaccine response.
- Intervention in the body’s natural hormones.
- Increased cholesterol and/or risk of obesity.
“PFASs do not break down easily in the environment and are toxic even at minute concentrations,” Dye said. “They must be removed and destroyed to prevent human exposure and negative impacts on the ecosystem.
“PFAS are so stable because they consist 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 water in very low concentrations, and you need to concentrate them and then destroy them.’
The modern way to destroy them is to burn them, which is 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.
A sustainable and inexpensive alternative
Dai and Yuan developed a method of using plant-based material to adsorb PFAS and dispose of them with the help of microbial fungi that literally eat the “eternal chemicals.”
“We have produced a resistant plant material that can be used to concentrate PFAS chemicals,” Dye said.
“The plant’s cell wall material serves as the basis for PFAS adsorption,” she said. “That material and the adsorbed chemical then serve as food for the microbial fungus. The fungus eats it, it’s gone, and you don’t have a disposal problem. In essence, the fungus performs a detoxification process.’
It’s 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 commercial applications
EPA has established a nationwide program to monitor the incidence and levels of PFAS in public water systems and is considering adding threshold levels of PFAS to drinking water standards.
“If the threshold levels become part of the drinking water standards, municipal treatment plants will have to comply with EPA regulations. Manufacturers will have to monitor these chemicals and remove them if necessary,” Dye said.
The innovative biomass rehabilitation that Dai and Yuan developed could help implement these changes more cost-effectively. Interest in this technology extends beyond drinking water standards.
“We live on a planet where all components interact,” Dye said. “People are concerned not only about the water, but also about the local crops produced using that water to feed the animals that are part of the food supply.”
