字幕列表 影片播放 列印英文字幕 Human-made chemicals that were once considered the peak of our ingenuity have come back to haunt us in a big way. They’re present in our soil, air, water... and that means they’re in us, too. And we don’t know how to get rid of them. But recent work promises a way to break down these compounds that most of us are exposed to every day, and the solution involves plasma. These ‘zombie chemicals’ that never die are called Per- and PolyFluoroAlkyl Substances, or PFAS for short. They’re a whole family of thousands of different compounds that are all based on the strongest bond in organic chemistry: the bond between carbon and fluorine. Because the C-F bond is so freaking difficult to break, PFAS have been used in tons of everyday products around the world since the 1940s as a handy barrier substance. These compounds are used as stain repellents, non-stick coating on cookware, and super-effective firefighting foam. They’re also used in semiconductors, cellphones, vehicle manufacturing, really... they’re everywhere. But the very trait that makes them so useful is also what makes them difficult to break down… even when you want them to. And while some of them may not be dangerous, we're still not sure what their long term effects are. Several public health studies have shown that PFAS are hanging around in the blood and urine of 95-97% of the U.S. population. They’re really hard for your body to get rid of, because you can’t break them down. And that means that as we get older, the amount of PFAS in our bodies may only increase. And you thought diamonds were forever. We’re still really trying to get a handle on what exactly they’re doing to our bodies. We’re pretty sure that two specific kinds of PFAS—PFO and PFOA—are hazardous to our immune systems and increase our cholesterol. They may alter our metabolism, our fertility, and pose risks to fetuses, like low birth weight. And perhaps most alarming of all, there is evidence to support a possible link between these PFAS and a higher risk of thyroid disruption and even cancer. More research is needed to understand exactly how these compounds are causing these changes, and what levels of which PFAS cause what changes, because honestly, we’re still figuring it out. But long story short: there are tons of them, they’re everywhere, and they’ve been nearly impossible to get rid of... until now. A new project out of the Air Force Civil Engineer Center has developed something called the Enhanced Contact Plasma Reactor, which is as exciting as it sounds. The device uses argon gas to push the PFAS to the surface of a sample of contaminated water. It then uses electrodes on either side of the isolated PFAS to generate plasma. Plasma is basically a big cloud of particles—positive ions and free electrons—that can knock other things apart… like that super strong C-F bond. The new plasma technology reduces the concentration of those two most dangerous PFAS to a safe level for drinking, and does it faster and cheaper than some of the other options out there. It’s a huge step because other methods for removing PFAS from contaminated water samples just filter them out. Then you have clean water, but you still have PFAS waste to deal with. While this method instead actually breaks the PFAS down into their different parts, making them easier to dispose of. This is a super exciting solution to the super staying power of PFAS, but it may still be quite difficult to apply this method to huge aquifers of drinking water. So the team is working on scaling up and making sure the tech can be easily mobilized at scale. Plus, it’s only one of several innovations that we’re gonna need... because what about PFAS in our soil, and in our air? Some other teams have demonstrated that soil microbes can eat and process a certain kind of PFAS, so that’s a cool possibility, and many other teams around the world are working on all kinds of innovations to make PFAS less ‘forever’. Hopefully as we learn more about the effect of PFAS and how to deal with them, we can better understand how to leverage all of their perks, but for a limited time only. If you want to learn about another surprising plasma purification innovation, then check out our video on a new virus filter here. And subscribe to Seeker to keep up with all of the latest tech that's helping us clean up our world. If you have another environmental remediation topic you want to see us cover, let us know down in the comments below. And as always, thanks for watching. I'll see ya next time.
B1 中級 這種新技術可以消除我們飲用水中的有毒PFAS。 (This New Tech Could Eliminate Toxic PFAS From Our Drinking Water) 30 1 林宜悉 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字