Teflon was discovered, by accident, in 1938 by Roy J. Plunkett. Teflon is a polymer (a plastic) with lots of convenient properties, in particular, the fact that is has a coefficient of friction that’s about the same as that of wet ice. This is why we use it as a non-stick surface for frying pans. What gives teflon its properties is that fact that the only element present in it other than carbon is fluorine. The carbon-fluorine bond is very strong, and that strength makes such compounds particularly stable. Perfluorinated organic compounds (where all hydrogens are replaced by fluorine) have since entered the market with any number of uses. One other important such substance is flame-smothering foam used by fire-fighters.
However, something we have learned in recent decades is that the advantages that modern chemistry brings to modern life often comes with a dark side, and perfluoroalkyl substances (PFAS) are no exception. The movie Dark Waters, released in late 2019 was based on events that happened in real life. The movie starred Mark Ruffalo as a lawyer who challenged Du Pont for dumping unregulated waste substances in a rural community in West Virginia, causing cattle to die and health problems in the community. The substance in question was perfluorooctanoic acid (PFOA). It got into the community water supply, and it was causing cancer as well as other health problems.
So now, more than 80 years after their introduction into the market, we have the problem of finding ways to remediate these substances that have found their way into the environment. This is difficult because, as stated above, once you make these compounds, they are extremely stable, and are hence very hard to destroy.
One strategy that is emerging is bioremediation: let microbes digest these substances, transforming them into simpler, safer compounds. I found an article about this in the trade publication for my professional organization, Chemical and Engineering News. This is what happened to the polychlorinated biphenyls (PCBs) that contaminated the sediments of the Hudson River for decades. It’s also what happened to the petroleum that contaminated the waters of the Gulf of Mexico after the Deepwater Horizon disaster. Bacteria with an appetite for these substance went after them and ate them. The fact that such bacteria exists has cause some scientists to conjecture that, somewhere in the world, there is a bacterium that will be able to digest every class of hazardous waste in existence. This is called the microbial infallibility hypothesis.
But PFASs are a really hard case. Carbon-fluorine bonds are extremely strong, and not much energy is released in their digestion. Further, unlike other hazardous compounds for which bacteria have played a role in remediation, PFASs lack a good “handle” that bacteria can use to start the digestion.
I don’t want to bore you too much with the details, but the studies performed thus far show promise. Depending on the compound and the bacteria, degradation of the compounds by this method have ranged from 60 % to 100 %. However, these methods have to be able to degrade these compounds not just in the laboratory at high concentrations, but also when they are in trace concentrations in the environment, which is yet another hurdle that must be crossed.
One fact that that was emphasized throughout the article is that the best way to remediate is not to have to do it in the first place. That is, we need to stop using these substances, presumably replacing them with other, less dangerous substances. Given how used to non-stick frying pans and the like we are, that is also a tall order, but it’s something that must be done in the long run.
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Top Comments (April 17, 2021):
From BeAPatriotPayYourTaxes:
Due to its flawless good sense, I nominate this comment by ol Dirtfarmer as a Top Comment. From zman1527’s recommended post Unproductive Firms Would Not Be Able to Stay Afloat By Underpaying Their Workers.
With all of the squabbling over the CORPORATE income tax rate in recent years, I have long maintained that the corporate income tax rate should be inversely proportional to the overall wage scale of what the corporation pays their employees. If their pay scale is so lousy their employees are on EIC, Food stamps, Public health care, etc. the corporation should be taxed to help pay for all of these things. If they pay well enough for people to live decently without taxpayer financed subsidies, then the corporation should be taxed at a much lower rate, probably less than half of the top corporate tax rate.
From Yasuragi:
From Denise Oliver Velez’ #BlackMusicSunday post today on Roberta Flack and her music, mww01833 tells about their introduction to Roberta Flack’s music.
Highlighted by Albanius:
This comment by learn in Greg Dworkin’s Abbreviated Pundit Roundup this morning.
Top Mojo (April 16, 2021):
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