Another big problem with these families of contaminants, is they are heavier than water.
Contaminants such as oil, gasoline, and diesel, are lighter than water.(Called LNAPL- light non aqueous phase liquids.) and therefore float on water.
So when they sink into the ground, they hit a water table and stop, floating on that water table. Water tables are about 5 to 50 meters underground - moving very very, slowly - usually off sight (towards a neighbor.) It is fairly easy to pump that to contaminated layer of water up, treat it, and pump it back down, a bit downstream.
Chlorinated and fluorinated compounds, and other similarly constructed organic compounds are DNAPL - dense non aqueous phase liquids.
They sink. They hit the water table, and keep sinking, not only below the water table, but further. Finding cracks in the bedrock and they keep sinking. It is almost impossible to get at them to clean them all up
. Some small fraction of the DNAPL pollutants may be transported with the ground water, the rest stays and goes deeper.
And you can't get at them. You need to drill: very deep, through bedrock, and many holes, which aren't connected. Read as: very very expensive.
Once you remove the source of the contaminants,. You can reduce the main part of the problem. They are also somewhat volatile, so they sometimes migrate up. Sometimes as gases. (But that's another story.)
Meanwhile, quite often the treatment technique, can make the contaminants more toxic! Oxidizing a contaminant with chlorine in it can turn it into a simpler, less complex contaminant, which may be more reactive, and/or more toxic.
In summary it's the sort of a system that is complicated and one has to understand it, and think about the possible scenarios.
Often it is cheaper and most realistic to pave such a site, hence isolating the contamination, underground. (In some cases, depending on the results of a risk analysis, continuous or yearly monitoring is mandated, to see if the contamination is spreading off site. For example dry cleaning solvents, may reduce to PVC (poly vinyl chloride), which may further to reduce to Vinyl Chloride - an even more toxic contaminant.
> Chlorinated and fluorinated compounds, and other similarly constructed organic compounds are DNAPL - dense non aqueous phase liquids. They sink. They hit the water table, and keep sinking, not only below the water table, but further. Finding cracks in the bedrock and they keep sinking. It is almost impossible to get at them to clean them all up . Some small fraction of the DNAPL pollutants may be transported with the ground water, the rest stays and goes deeper. And you can't get at them.
This sounds like a self-solving problem: pollutants sinking deep, well past water table, near-impossible to get at, never to be seen again (and presumably recycled by Earth's geology in a hundred thousand years). What am I missing?
> They are also somewhat volatile, so they sometimes migrate up. Sometimes as gases.
Also, I can imagine that while they stay on the bottom they still contaminate some water above slightly and continuously since molecules in liquids generally like to move around a bit.
I'd be sufficiently happy if trendy ecovirtue-signaling bars and restaurants would stop putting cardboard straws covered with the stuff in my drink. Baby steps, and no drilling required.
My first thought while reading the article was that this could be used as a water supply treatment, not necessarily source remediation. Any thoughts on that?
These general strategies of UV-powered destruction of halogenated organic chemicals have been known and studied for decades. The real issue in terms of pollution control is that you have to build expensive backends on chemical factories that make the fluorinated or chlorinated products to destroy the waste, and this can easily double the production cost, so chemical corporations have lobbied hard against things like the Clean Water Act.
See this from 1986, for example, which looks at chlorinated organics (granted, fluorinated organics are harder to break down to CO2 + non-reactive fluoride ions)
SUNDSTROM et al. (1986). Destruction of Halogenated Aliphatics by Ultraviolet Catalyzed Oxidation with Hydrogen Peroxide. Hazardous Waste and Hazardous Materials, 3(1)
Cleaning up after the fact is highly inefficient, it's far better to just ensure that facilities like Teflon factories aren't emitting any waste in the first place.
This is a part in realization of the true cost of producing things.
In Sweden we call “sale” a “realization”, meaning consumers pay the true cost without markup. I always say we’re realizing the wrong way - cost should quadruple for every H&M item we buy, and the money should go to enforcement of clean production.
Hard sell, but eventually a must; cut profit and increase price at the same time.
If we can’t get corporates to fund the UV treatment, can we get taxpayers to fund it on water treatment plants so we aren’t drinking and processing food with infested water?
Things like fire extinguishing foam are probably some unavoidable evil. But realistically how many of us are buying rainproof stuff when all we needed was something water-resistant?
Recently I was looking for a tweed winter jacket only to realize that those are now also being treated with water resistant coatings!
Most use-cases people are out in the rain for stretches of 20min and run inside for shelter shortly after. Unless you work outdors or are on a day long hike/cycle there is no need to have this much 100% waterproof stuff. Waxed/greased materials or just wool do a good enough job for most mortals and have served us well for thousands of years.
I regularly bike in the rain for 30 minutes or more. My gear is all nylon with a non-PFOA wax coating. It doesn't perform as well, and my jacket will get saturated after about 45 minutes. I deal with that by wearing something under the jacket (usually a fleece). Absolutely worst case, the fleece gets slightly damp but I am still perfectly comfortable for many hours.
The only other issue I see is that I have to reapply the coating about once a year, or after I machine-wash the jacket.
Overall these are very minor inconveniences. I wonder if anyone really needs the performance gains of these chemicals - you only see the advantage in really bad weather conditions over long periods of time. How many people are doing day-long hikes in pouring rain?
How many times have you seen ads for Gore-Tex anything? How many waxed canvas coats are you able to find in normal outdoor shops or in normal clothing retailers?
There is a lot of money in outdoor gear and it is all being spent on pushing high tech solutions.
You basically have to go out of your way to find some grandpa shop or 'out of fashion' clothing (mostly shops selling hunting clothing/gear) to find reasonable alternatives.
Pearl Izumi rain pants work great for me for heavy rain. I never got a proper upper cover just a hoody jacket cover thing that doesn't do as good a job of keeping water out as the pants. I wear a coat sometimes and needed something to pull over a coat. The rain pants pull over existing pants very readily, the top has a wider variation in thickness I need to cover so I never got a proper rain jacket from Pearl Izumi which is more on the tight end of a fit.
I wonder how harmful are waterproofing sprays like this:
https://www.decathlon.co.uk/p/water-repellent-re-activator-s...
they are incredibly effective in keeping my shoes dry but seeing people using it on national park trailheads makes me a little nervous.
I recently bought kids rain boots, just normal vulcanized rubber which is itself water proof.
The lady at the counter asked if I wanted a water repellent coating (PFC) on it for extra money. They are exposing toddlers to this crap for literally no benefit.
The pace at which we allow chemistry innovation to permiate consumer markets needs to be curbed.
> Waxed/greased materials or just wool do a good enough job for most mortals and have served us well for thousands of years.
Yes, but they're more expensive to manufacture. Capitalism is looking to min/max these things, as are consumers since people can't afford wool / waxed materials anymore - also because they can't find them anymore, except at specialist and smaller venues.
We tried shopping for new winter coats the other day, most of what we found was plastic or some cotton. The more expensive stuff we found was more polyester, but at 6x the price. There was no shop (on the high street) that sold anything woolen or cotton.
I sympathize, though, because in my quest to help you I checked two or three other places briefly (Macys, Everlane) and the offerings I found first all were wool blends
It sounds like this research is pretty promising. I will be very happy if this can be deployed in water treatment plants.
However, there is a remaining problem of removing these chemicals from everything else. What about crops grown in contaminated soil, or meat from animals who've eaten contaminated food? It seems that a lot of fish and shellfish may be contaminated. [1]
Right, but water is the input for… pretty much everything we consume and also the output, so all that should matter is there is a treatment step somewhere in the cycle.
Related - I spent years injecting molasses into the ground to do VOC remediation. https://semspub.epa.gov/work/HQ/401583.pdf We used GeoProbe tooling to get the molasses down there.
> Given the regulatory push, Liu’s laboratory team is “marching toward commercialization” with help from a $50,000 proof-of-concept grant from UCR’s Office of Technology Partnership to scale up this technology to handle larger volumes of water, Liu said.
One $50k grant? That seems like a tiny amount for possible fix to such a big problem.
The primary route of elimination of PFAAs is through the kidney in the urine (Han et al., 2008). Other important clearance pathways include menstruation (Harada et al., 2005; Taylor et al., 2014; Park et al., 2019; Ding et al., 2020), pregnancy (Monroy et al., 2008) and lactation (Bjermo et al., 2013). Sex hormones have been identified as a major factor in determining the renal clearance of PFAAs. One study examined the role of sex hormones and transport proteins on renal clearance and observed that, in ovariectomised female rats, oestradiol could facilitate the transport of PFAAs across the membranes of kidney tubules into the glomerular filtrate, resulting in lower serum concentrations (Kudo et al., 2002).
Han X, Mingoia R, Snajdr S, Yang C, Nabb D. Uptake of perfluorooctanoate in freshly isolated hepatocytes from male and female rats. Toxicol Lett 2008;181:81–86.
Harada K, Inoue K, Morikawa A, Yoshinaga T, Saito N, Koizumi A. Renal clearance of perfluorooctane sulfonate and perfluorooctanoate in humans and their species-specific excretion. Environ Res 2005;99:253–261.
Taylor KW, Hoffman K, Thayer KA, Daniels JL. Polyfluoroalkyl chemicals and menopause among women 20-65 years of age (NHANES). Environ Health Perspect 2014;122:145–150.
Park SK, Peng Q, Ding N, Mukherjee B, Harlow SD. Determinants of per- and polyfluoroalkyl substances (PFAS) in midlife women: evidence of racial/ethnic and geographic differences in PFAS exposure. Environ Res 2019;175:186–199.
Ding N, Harlow SD, Batterman S, Mukherjee B, Park SK. Longitudinal trends in perfluoroalkyl and polyfluoroalkyl substances among multiethnic midlife women from 1999 to 2011: the Study of Women’s Health Across the Nation. Environ Int 2020;135:105381.
Monroy R, Morrison K, Teo K, Atkinson S, Kubwabo C, Stewart B, Foster WG. Serum levels of perfluoroalkyl compounds in human maternal and umbilical cord blood samples. Environ Res 2008;108:56–62.
Bjermo H, Darnerud PO, Pearson M, Barbieri HE, Lindroos AK, Nälsén C, Lindh CH, Jönsson BAG, Glynn A. Serum concentrations of perfluorinated alkyl acids and their associations with diet and personal characteristics among Swedish adults. Mol Nutr Food Res 2013;57:2206–2215.
Kudo N, Katakura M, Sato Y, Kawashima Y. Sex hormone-regulated renal transport of perfluorooctanoic acid. Chem Biol Interact 2002;139:301–316.
A correction. The Kudo et al., 2002 study found that estradiol lowered the filtration rate in ovariectomised rats. But supplemental estradiol did improve the clearance rate for intact male rats.
> The patent-pending process infuses contaminated water with hydrogen, then blasts the water with high-energy, short-wavelength ultraviolet light. The hydrogen polarizes water molecules to make them more reactive, while the light catalyzes chemical reactions that destroy the pollutants, known as PFAS or poly- and per-fluoroalkyl substances.
Oh. That does not sound like a process that I want happening inside my cells. So, yeah, what you said. No progress toward getting it out of people.
But couldn't this be made into an intermediary device that one would hook up to their main water connection to a home, like a reverse osmosis type device, and ensure that your tap water is pure?
Then, if you're flushing your system with such pure water - maybe it does a good job on the liver and kidneys?
I drink A LOT of water each day... and what I would also like to know is if this system has any effect on the removal of fluoride from water (tap water)
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Side note: My dad was very good friends with the CEO of Alcoa for many years... and fluoride is a side product of aluminum manufacture, and the quote Ill never forget was "The reason the put fluoride in the water is they dont have any other place to put it - so they store it in your liver"
I dont know if that was a joke - but I was like 15 when he said it, so I wasnt sure if he was fn with me....
He was probably joking, but that is one of the many conspiracy theories that exist about fluoridated water so it's possible he was a believer. The actual reason the put fluoride in the water is because it helps prevent cavities. Reverse osmosis filters can remove it.
> In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang for the first time combined 27 studies and found strong indications that fluoride may adversely affect cognitive development in children.
My GF is from the UK where they fluoridate the water. Tap water is undrinkable (flavor) and should only be used after boiling (evaporates the fluoride and chlorine). She had pretty serious fluoridosis (demineralisation of her teeth) which sorted itself out while living here (NL, we're lucky to have fresh groundwater).
IMO, fluoride is fine for external use (in toothpaste), but shouldn't be consumed. If I may put on my conspiratorial tin-foil hat, it's a means of population control - keep them stupid and docile.
I'd wait for better research than a review of a bunch of flawed studies from china where they have a lot of environmental exposure to things that could impact IQ besides the fluoride in their water.
Fluoridated water doesn't taste any different than non-fluoridated water, so whatever taste the water in the UK has doesn't come from that, and leaving it out will not remove the fluoride through evaporation. That trick does work for chlorine though.
One conspiracy is that Nazi's or Russians used fluoridated water as a mind control substance that could make people stupid and willing to accept whatever they were told, but that's been repeatedly debunked. It might be exciting to think about, but there's nothing to support that fluoride (which often occurs naturally in water) has mind control properties. In the US all you have to do is look around you to see that people have zero problems resisting and complaining about the government (sometimes to their own detriment). The fluoride doesn't seem to be effective for anything but keeping teeth healthy.
As for harm to people's IQ, we don't have the evidence to support that at the levels added to municipal water, and I'd suggest a bigger contributor to the problem of lower IQs might be lead and mercury. We've been spooning heavy metals directly into our children's mouths for decades and you don't need conspiracy theory websites or weak research on children living on the other side of planet to know that it's been going on here in the US.
It's not being done for government mind control reasons though (the government is calling for it to stop in this instance) instead it's being done because corporations are greedy, don't care who they poison if doing so will grant them higher profits, and the regulatory agencies which should protect us and our children are weak and captured by industry.
It's strange how conspiracy theories seem to take up people's attention causing them to passionately rail against myths while real atrocities are going on around them largely ignored.
As I understand it, this is a process, not a filter, so it does not remove any matter from the water, it changes the PFAs into something else, presumably something that is not as harmful.
Carbon filtration will remove any contaminants (e.g. Florida, chlorine) in your water through adsorption. For the money, you can't beat it.
He was half-joking. A great book on this topic is "The Fluoride Deception", pretty interesting documentation and very restrained in jumping to conclusions.
Btw, it would be a bane of aluminum producers if they had to find safe ways to dispose of it, instead they get to sell it to utilities.
I mean it'll cost a lot of hydrogen to do at that scale, but they're considering and setting up projects to build hydrogen production plants to turn any excess electricity from e.g. solar panels into hydrogen. It scales up and down easily, and hydrogen stores pretty well and has plenty of applications, from this to hydrogen cars / trucks, etc.
They're even thinking of reusing the existing natural gas lines throughout the country to transport hydrogen. Probably not to homes though.
This would be a dialysis machine. There is some evidence that they're capable of removing some perfluorinated chemicals, though it seems they aren't effective against all types, at least at low concentrations. I'm sure there are private clinics somewhere that will take your money and hook you up for a blood detox, but it's a four hour process so not a practical solution for everyone.
Aren’t they finally starting to think about letting gays donate blood again? I know we aren’t there yet but sounds like at least some rumblings of progress…
environmental safety science has a messaging problem. it’s too polarized
- “forever chemicals”… actually aren’t forever
- plastic never degrades… until we found the right enzyme for it
- were “past the point of no return” for greenhouse gasses temp increases… until we find a solution for it
the way these problems are communicated are done in a way it seems to scare people into thinking a certain way. but i think it reinforces the echo chamber for those who already believed it and just erodes trust instead for the rest
I don’t think it’s polarized, but there’s a language barrier: when environmental scientists speak, you should probably suffix everything they say with “in the environment.”
Forever chemicals are indeed forever, in the environment, because there are virtually no natural processes that break them down on human timescales. Many plastics similarly do not degrade in the environment on human scales.
It’s incumbent upon you, as a lay person, to understand that science isn’t categorical in nature. When scientists use phrases like “forever,” they’re making statements relative to the domain of interest.
You're looking at it from the vantage point of "the future". For some span of time, "plastic never degrades". Then someone discovers something new, and after that plastic degradation becomes possible (though not widespread).
I might be wrong but I think parent is referring too the fact that, this incorrect messaging causes a huge amount of stress for little gain and it also kind of looks silly when it turns out to be wrong thus diminishing the credibility of SCIENCE!
To call something a "forever chemical" is talking in absolutes, and we should know that most things aren't absolute.
This may be a bit pedantic, but: it's not that what we know changes, per se.
We weren't mistaken in thinking that plastic doesn't degrade.
We mean: as of now, we have no possible method to make plastic degrade. It _may be_ we will develop such a method in the future, but it's reckless to rely on the _possibility_ of a future discovery.
* Forever chemicals are a huge problem, and even TFA does not give any hope at all in reducing the insane amounts of PFAS and related chemicals in the environment. We need to stop releasing mind-boggling amounts of it before we come up with nifty techniques to destroy a few millilitres of it
* We have found enzymes that degrade PET, which is highly recyclable anyway. There are no hints at all that we would be able to first find enzymes for the hundreds of other plastics, and then manufacture and release enough into the environment to make a difference.
* The seriousness of climate change has been communicated in every single way across the spectrum of possible approaches. Our civilization is simply not equipped to handle a problem of this magnitude. We are past the point of no return, and if you actually looked into our energy usage and what it would take to solve this with technology, you would come to the same conclusion. But feel free to keep denying it, makes no difference in the end.
I'm just sick of the phrase "forever chemicals" because everyone who uses it sounds like they're dumbing their message down for us. We have mortgages, we can handle grownup words.
If they don't press, if they don't do the scaremongering, do you think the world's governments and sciences would put money and time into solving the issue? Probably not; it's only thanks to continued activism and policy changes that e.g. CO2 emissions in Europe have been reduced to the degree they are.
Of course, it's a force that also has to compete with population increase.
I think that's a bit ridiculous - obviously science and the scope of human knowledge changes as we move forwards. Yes there was no solution, yes there now may be a solution.
I would hope people can understand that reporting is based on current knowledge and is subject to change in the future - especially in science.
You can't go back the way you came, reducing emissions again, even bringing the global temperature back down won't recreate the glaciers. Even if you get the temperature much lower, glaciers may not form at the same location again
The hard part is the sheer size of the problem: miles of aquifers, 100s of feet down, billion of gallons, etc. The destruction needs more that pump and treat.
For most urban areas where this contamination is prevalent (old dry cleaner & brake cleaner spills), there are a limited number of well heads that pull from the polluted aquifers to supply municipal water.
Not sure why you mentioned "african village", sounds like you have some prejudices about those.
Anyway, probably not, since the process requires hydrogen. I think if you're not near a water mains, other means of water purification will be a bit more important.
Because it shouldn’t be limited to wealthy, industrialized nations. Especially when those same places are the ones who created the problem in the first place.
