The term "forever chemicals" is used to describe a group of manufactured chemicals. They can't be eaten, they can't be burned, and they can't be watered. Toxic chemicals can become a problem for generations to come if they're not buried.
The chemists at the university did the seemingly impossible. The research team used low temperatures and inexpensive reagents to develop a process that causes two major classes of PFAS compounds to fall apart.
The simple technique could be used to dispose of harmful chemicals, which are linked to many dangerous health effects in humans, livestock and the environment.
The leader of the study said that PFAS has become a major societal problem. Even a small amount of PFAS can cause negative health effects. We need to do something about this problem. We wanted to use chemistry to come up with a solution that the world can AnyFormatp use. Our solution is simple, yet unrecognized.
The Weinberg College of Arts and Sciences has a chemistry professor named Dichtel. The paper's co-first author is Brittany Trang, who conducted the project as a part of her PhD.
The same thing as lead.
For 70 years, PFAS has been used as a waterproof agent. They are found in products that resist grease and oil.
PFAS has made its way out of consumer goods and into our drinking water and even into the blood of most Americans. Increased risks of cancer, reduced immunity to infections and increased cholesterol levels are some of the health effects that are not yet fully understood. The EPA recently declared several PFAS to be unsafe even at trace levels.
The EPA revised its recommendations for PFOA recently. Several PFCs are in the same category as lead.
Bonds are unbreakable.
There aren't many solutions for how to dispose of PFAS after it is removed. There are only a few options that involve destruction of PFAS at high temperatures and pressures.
Some of the compounds were being released into the air by a plant that claimed to be burning them. The compounds were released from the smokestacks. The strategy of burying the compounds in landfills has been a failure. It's a guarantee that you will have a problem 30 years from now because it's going to slowly get worse. The problem was not solved by you. The can was kicked down the road.
There is a secret to its indestructibility. The strongest bonds in organic chemistry are contained in PFC. fluorine is the most negatively charged element in the table. Carbon is more willing to give up electrons than the other way around.
The recipe for a strong bond can be found in the difference between the two atoms.
Pinpointing PFAS's weakness.
The team studied the compounds and found a weakness. The bonds of carbon-fluorine are very strong. There is a charged group at the end of the molecule. This head group was targeted by Dichtel's team by heating the PFAS in dimethyl sulfoxide. The process left behind a tail.
"That triggered all these reactions, and it started spitting out fluorine atoms from these compounds to form datememe datememe, which is the safest form of datememe." The charged head group is the problem.
Other researchers have used high temperatures in the past. The new technique uses milder conditions and a simple reagent, making it more practical for widespread use.
They discovered that the pollutants fall apart by different processes than they were thought to. -8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873-8873 According to their calculations, PFAS falls apart due to more complex processes. Although it was assumed that PFAS should fall apart one carbon at a time, the simulation showed that it actually falls apart 2 or 3 carbons at a time. Researchers can confirm that benign products still exist by understanding pathways. Further improvements to the method can be helped by this new knowledge.
"This proved to be a very complex set of calculations that challenged the most modern quantum mechanical methods and fastest computers available to us," said Houk. In the last 10 years, we have been able to take on large mechanistic problems like this, evaluating all the possibilities and determining which one can happen at the observed rate, thanks to the use of quantum mechanics. Brittany and Yuli worked long distances to solve the problem.
It was 11,990 to go.
The effectiveness of the new strategy will be tested next. They were able to degrade 10 perfluoroalkyl carboxylic acids and perfluoroalkyl ether carboxylic acids. More than 12,000 compounds have been identified by the U.S.EPA.
Dichtel is still hopeful.
One of the largest classes of PFAS was addressed by our work. There are other classes that do not have the same weakness. We can destroy it if we can identify it.
The Center for Water Research and the International Institute for Nanotechnology are all part of the Institute forSustainability and Energy.
The study is in the journal Science.More information: Brittany Trang et al, Low-temperature mineralization of perfluorocarboxylic acids, Science (2022). DOI: 10.1126/science.abm8868. www.science.org/doi/10.1126/science.abm8868 Journal information: Science