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January 9, 2024

Tech Solutions to Removing PFAs

New technology provides solutions to removing PFAS from drinking water

Uplifting News: PFAS ‘forever chemicals’ may not be so forever thanks to new tech

From drinking water to waterproof clothes, from cookware to personal care and cosmetics, ‘forever chemicals’ known as PFAS are unavoidable today. They are in our homes, offices, and supermarkets posing a serious threat to human health, even at low levels. But, thanks to new tech, there may be a solution to removing PFAs.

What are PFAS?

PFAS, short for per-and poly-fluoroalkyl substances, were first introduced in 1946 by DuPont on cookware coated with Teflon, a type of plastic to create nonstick, waterproof, noncorrosive, and nonreactive surfaces. [1] Teflon has since been proven responsible for  community health hazards it caused. In 2001, a class-action lawsuit in West Virginia revealed PFA contamination in the local tap water which was linked to cancer of the liver, kidney, and pancreas as well as other health impacts like increased cholesterol and weakened immunity in children. [2] In both human and animal studies, PFAS are shown to disrupt natural bodily function and development including altered metabolism, fertility, and reduced fetal growth. [3]

The molecules of PFAS bond carbon and fluorine atoms together--one of the strongest single bonds in chemistry. This means PFAS cannot degrade so easily. [3] Erik D. Olson, the senior strategic director of health and food with the environmental advocacy group National Resources Defense Council (NRDC), explains that PFAS were deemed to live ‘forever’ because “[f]irst, they resist breakdown in the environment and in our bodies and second, move quickly through the environment, making their contamination hard to contain.” [4]

What can Technology do?

The following technologies are processes used today to extract PFAS from drinking water:

Granular activated carbon: This method absorbs PFAS molecules as water flows onto the surface of carbon beds and is the most effective. However, because other compounds can be absorbed too, it reduces the surface area, and therefore, capacity for PFAS---especially smaller PFAS. To dispose, used carbon can either be landfilled or regenerated. [5]

Ion-exchange resins: This method allows for positively charged material to bind with negatively charged PFAS as they pass through packed beds in granular form. Still,  molecules other than PFAS can bind to their positive charge and reduce the bed’s capacity. While regenerable resins are cleaned and reused, single-use resins are landfilled. [5]

Reverse osmosis: This method pressurizes contaminated water through a semipermeable (allowing some but not all substances to pass) membrane that filters out PFAS and is the most energy intensive. It may also filter important minerals from drinking water. The filtered water becomes liquid waste, returning contaminants to the environment. [5]

Conclusion

These methods, although imperfect, help us move closer to eradicating PFAS --‘forever chemicals’ -- from our bodies and environment. International research teams at UCLA, Northwestern and the University of Chinese Academy of Chemistry in Shanghai, China are investigating how else to effectively eliminate PFAS, including a process of intense heat and solvents. [6] With time and commitment, PFAS will not be so forever.

References

[1] https://www.ewg.org/what-are-pfas-chemicals

[2] https://www.ewg.org/news-insights/news/why-are-dupont-and-chemours-still-discharging-most-notorious-forever-chemical

[3] https://www.niehs.nih.gov/health/topics/agents/pfc/index.cfm

[4] https://www.nrdc.org/stories/forever-chemicals-called-pfas-show-your-food-clothes-and-home

[5] https://cen.acs.org/environment/persistent-pollutants/Forever-chemicals-technologies-aim-destroy/97/i12

[6] https://grist.org/science/pfas-not-forever-after-all/