New way of making water globally safe

Los Angeles - People around the world are despairing at so many reports that water sources have been thoroughly infested with hazardous human-made chemicals that last for thousands of years, making even rainwater unsafe to drink.

Using common reagents in heated water, chemists can break down human-made chemicals, leaving only harmless compounds.

UCLA and Northwestern University researchers have developed a simple way to break down almost a dozen types of nearly indestructible forever-chemicals at relatively low temperatures with no harmful by-products.

In a paper just published in the journal Science, the researchers show that in heated water common, inexpensive solvents and reagents severed molecular bonds in chemicals that are among the strongest known and initiated a chemical reaction that gradually nibbled away at the molecule until it was gone.

The simple technology, the comparatively low temperatures and the lack of harmful by-products mean there is no limit to how much water can be processed at once. The technology could eventually make it easier for water treatment plants to remove chemicals from drinking water.

PFAS chemicals are a class of around 12,000 synthetic chemicals that have been used since the 1940s in non-stick cookware, waterproof makeup, shampoos, electronics, food packaging and countless other products. They contain a bond between carbon and fluorine atoms that nothing in nature can break.

When these chemicals leach into the environment through manufacturing or everyday product use, they become part of the Earth's water cycle.

Over the past 70 years, PFAS have contaminated virtually every drop of water on the planet, and their strong carbon-fluorine bond allows them to pass through most water treatment systems completely unharmed.

They can accumulate in the tissues of people and animals over time and cause harm in ways that scientists are just beginning to understand. Certain cancers and thyroid diseases, for example, are associated with PFAS.

Scientists are experimenting with many remediation technologies, but most of them require extremely high temperatures, special chemicals or ultraviolet light and sometimes produce by-products that are also harmful and require additional steps to remove.

Researchers believe their method will work for most PFAS that contain carboxylic acids and hope it will help identify weak spots in other classes of PFAS. They hope these encouraging results will lead to further research that tests methods for eradicating the thousands of other types of PFAS.