[HN Gopher] Sunlight-activated material turns PFAS in water into...
___________________________________________________________________
Sunlight-activated material turns PFAS in water into harmless
fluoride
Author : bookofjoe
Score : 64 points
Date : 2025-08-10 16:31 UTC (6 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| nick238 wrote:
| The Materials Science Gameplay Loop:
|
| 1. Invent fantastic new material that does a heretofore novel
| reaction or one with improved performance (chemical,
| photovoltaic, etc.)
|
| 2. Do #1 without lead, cadmium, mercury, or arsenic.
|
| SociallyAwesomeAwkwardPenguinMeme("Turns PFAS to fluoride",
| "Contains Cadmium")
| momoschili wrote:
| 3. Do #2 without platinum, palladium, rhodium, ruthenium to
| make it economically viable
| 3eb7988a1663 wrote:
| Is that much of a problem for a catalyst? Presumably you do
| not need many of these: at water treatment plants and at the
| waste-stream for manufacturing processes which emit PFAS. You
| might not be able to justify the expense inside your home
| water purification system, but it could still be cost
| effective for large scale installations.
| momoschili wrote:
| it depends on the scale and the required amounts. If having
| a limited amount of catalyst wasn't such a big problem I
| suspect hydrogen power would have been much more
| economically viable.
| ambicapter wrote:
| I thought the point of catalysts was that they don't get
| used up in the reaction they promote.
| djtango wrote:
| The real world is messy - catalysts gradually need
| replacement over time in non lab conditions
|
| https://en.m.wikipedia.org/wiki/Catalyst_poisoning
| throwup238 wrote:
| You would need a lot of catalyst because the water
| infrastructure to supply several hundred million people in
| the US is massive, let alone the rest of the world.
|
| The problem with those catalysts is that the latter two are
| minor components of platinum and copper/nickel ores and
| despite how expensive they are, the extraction is only
| economically viable as part of other mining. Their supply
| can only grow as much as platinum extraction allows and
| demand is already pretty significant with environmental
| regulations often necessitating their use. Any more demand
| for them will cause their prices to rise dramatically and
| its a long way before they become profitable enough to mine
| on their own (flooding the platinum market in the process
| which has _much_ higher yields from the ores).
| SoftTalker wrote:
| Activated carbon filtering removes up to about 75% of PFAS.
| Reverse-osmosis removes almost all.
|
| Doesn't get rid of them, to be clear. It would still be
| better if a way could be found to chemically (and cheaply)
| convert them to something less harmful.
| N2yhWNXQN3k9 wrote:
| > Activated carbon filtering removes up to about 75%
|
| Seems like the limitation must be more than reducing
| concentrations in fluid? Otherwise you'd just do multiple
| passes?
| BugsJustFindMe wrote:
| > _Activated carbon filtering removes up to about 75% of
| PFAS_
|
| Common inexpensive non-RO filter systems come with
| independent test results showing 99% removal of PFOA/PFOS
| (see e.g
| https://www.brondell.com/content/UC300_Coral_PDS.pdf). Do
| we have reason to believe that other PFAS don't filter as
| easily?
| SoftTalker wrote:
| AIHI the shorter PFAS molecules are not captured as
| effectively by activated carbon.
| momoschili wrote:
| Yes, the key here is the degradation of the forever
| chemical, not the removal. Removal itself doesn't really
| change the environmental scale of it
| KennyBlanken wrote:
| Alternative path, like with General Electric:
|
| Invent seemingly fantastic new material. Discover it is harmful
| to humans and wildlife, accumulates in groundwater, etc. Bury
| that discovery.
|
| Get caught after decades of wild profits, the occasional secret
| settlement, and spend a decade more fighting legal action
| before finally running out of appeals or the writing is on the
| wall, and accept it and pay out.
|
| Start selling water filtration systems, thus profiting off
| people dealing with your pollution.
|
| This is what I find so frustrating about "the fight against
| cancer." I'm convinced cancer is so prevalent because
| corporations are poisoning the shit out of our environment, and
| thus our water supply, our food, our air. Because we're not
| equipped with timestamping chemical detection systems, it's
| difficult to identify the exposure that caused it or increased
| the person's risk, so industry gets a "freebie" death nobody
| can pin to them. As long as the chemical isn't toxic enough to
| be obvious - the companies get away scott free, despite an
| _extensive_ history of the chemical industry time and time
| again coming up with some major novel chemical that comes to be
| used all over society and turns out to be toxic.
|
| Bill Moyers once submitted his blood to a lab and asked them to
| test for everything they could identify in terms of industrial
| chemicals, pesticides, etc. The blood was a veritable toxic
| soup (and some of the control sample containers were
| contaminated from the supplier, showing how pervasive the
| toxins are):
| https://www.pbs.org/tradesecrets/problem/popup_bb_02.html
|
| You don't "fight cancer" doing walks and charity balls and
| cute-kid-starts-fundraiser-because-friend-dies-from-leukemia.
| You fight cancer by addressing the toxins being pumped into us
| in the name of profit and "bettering society", allowed to get
| away with it because of how difficult it is to show any
| particular chemical directly caused the cancer.
| anonymars wrote:
| If only the vaccine-autism energy could be directed in the
| right place
|
| PS not to diminish GE's game but they certainly weren't the
| only player. This one always stuck with me: https://en.wikipe
| dia.org/wiki/Minamata_disease#Wastewater_tr...
| exogenousdata wrote:
| Sadly the goal of vaccine-autism energy has largely become
| to destabilize western nation states. But I share the
| sentiment!
| prophesi wrote:
| It's a bit disheartening to see that the Bill Moyer's
| documentary came out in 2001, and not much has changed to
| keep these corporations accountable.
| nraynaud wrote:
| I'm a bit confused, are they suggesting that a cadnium coumpound
| to treat PFAS is a done deal?
| pxeger1 wrote:
| Ignoring the cadmium problem, is fluoride really harmless? I
| don't know what concentration of fluoride you'd end up with from
| converting typical PFAS pollution, but if you get enough fluoride
| it is acutely poisonous, which might be worse than the
| carcinogenic PFAS. (Likewise, it might be worse for the
| environment)
| nick238 wrote:
| Fluoride doesn't bio-accumulate like PFAS do, which has a
| strong affinity for proteins and fats in organisms. Constantly
| drinking water with 0.5-1 ppm fluoride may cause minor side
| effects like mild dental fluorosis, but you'll excrete almost
| all the excess as it's very water soluble. Drink water with any
| PFAS, and your body will strongly hold on to it all.
| formerly_proven wrote:
| "0.5-1 ppm" covers what's considered the optimum level of
| fluoride in drinking water, so I doubt you'd get dental
| fluorosis from that. Coincidentally, if you calculate the
| equivalent dose that you'd give babies (via dissolved vitamin
| D + fluoride tablets), you also end up at about 0.3-0.5ppm.
| bawolff wrote:
| Everything is toxic at a certain conentration, but as far as i
| know PFAS is a million times more toxic than flouride.
|
| According to the EPA safe level for flouride for drinking water
| is up to 4 mg/L. The epa level for PFOS is 0.000004 mg/L,
| literally a million times lower.
| sitkack wrote:
| I thought the EPA was deregulating everything _except_
| flouride which it was going to deem a poison.
| exogenousdata wrote:
| Fair point. We should probably have some way to refer to US
| gov't funded scientific orgs & their
| research/recommendations before vs after the 2nd Trump
| Administration.
| ChrisMarshallNY wrote:
| Fluoride?!!
|
| Isn't that supposed to be some kind of demonic juice?
|
| Why else is the government so intent on making sure that there's
| none in our water? I'm sure that they would much rather have the
| PFAS, produced by their nice, generous, industrialist bros.
| sitkack wrote:
| And PFAS are used heavily in the manufacturing of microchips
| (photoresist and etching).
___________________________________________________________________
(page generated 2025-08-10 23:01 UTC)