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Smash55 t1_iso8pj0 wrote

Ultrathin polymer sounds like future microplastics to me

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StaleCanole t1_isofov5 wrote

I has the exact same thought. Sounds like something i want in my water source.

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[deleted] t1_ispefev wrote

[deleted]

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McManGuy t1_isqp1sw wrote

I mean, if that were true, it's a problem that would solve itself for the water supply. The problem would be the buildup in wildlife.

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mikeblas t1_isnnlwg wrote

Hasn't membrane desalination technology existed for decades? For example: https://www.mdpi.com/2073-4441/5/1/94/htm

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UnfinishedProjects t1_isp24ar wrote

Isn't the problem that they get destroyed really quickly?

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ascandalia t1_isra4nc wrote

Nope. They can last for years depending on pretreatment and source water quality. They have gotten a lot cheaper in the last 20 years. These articles come out pretty often and are promising pretty marginal improvements on existing technologies.

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ittybittycitykitty t1_isoguqn wrote

I would be nice to know how this stuff compares to current RO material. Isn't there a basic amount of energy required to desalinate water, that you can't do it for less?

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Zout t1_isp91pe wrote

True, you have to overcome the osmotic pressure, which would be the same for current RO membranes or these new types. This is where the bulk of the energy is used. Reading the article I don't really get what improvement is made with these membranes. One the one hand the article claims a high flux for the new material, on the other hand fouling, stability and mechanical strength seems to be among the problems to solve.

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kittenTakeover t1_ispcoa1 wrote

Can anyone clarify the economics of desalination for me? I consistently see stats that say that desalination costs around $3 per 1000 gallons or $0.003 per gallon. Similarly I see info saying that the US uses around 200 gallons per day per person. That equates to $219 per person a year. That seems cheap. What am I missing?

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gjallerhorns_only t1_istje1x wrote

It costs over 100 million to build a desalination plant and politicians don't want to drop the coin.

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kittenTakeover t1_istk5wt wrote

Are you saying high upfront cost is the only issue?

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gjallerhorns_only t1_isu4dbt wrote

As I understand it, it's that and maintenance that are the reason we don't have more desalination plants.

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dsmith422 t1_isxudz7 wrote

That making water for people to use isn't the issue. Its water for farming that is the issue. Desalination to create water for traditional farming is a money losing proposition.

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kittenTakeover t1_isy15qy wrote

Are you saying that the 200 gallons per day per person doesn't include water used in product consumption?

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tiregroove t1_isnnt93 wrote

Great now what do we do with all the excess salt?
Humans always thinking of solutions but always creating another problem in the process.

https://www.reuters.com/article/us-environment-brine/too-much-salt-water-desalination-plants-harm-environment-u-n-idUSKCN1P81PX

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E_Snap t1_isnqxu9 wrote

You stop intentionally extracting salt from other sources and use the salt that you get from this process instead. Convert sea salt farms to use wastewater from these. Use it as a chemical feedstock if eating it gives folks the willies.

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Grapesoda5k t1_isob8xw wrote

Its not that simple. The brine created from desalination is toxic.

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ArmadilloReasonable9 t1_isp2oel wrote

It’s toxic because of the concentration if it was evaporated it’d still just be sea salt.

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Grapesoda5k t1_isp2wgh wrote

That's not what toxic means.

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ArmadilloReasonable9 t1_isp5lo0 wrote

That’s exactly what it means, there’s a safe amount of any substance. A substance is toxic when it harms an organism. You can’t just eat sea salt, even water is toxic when you drink enough of it to dilute you blood to the point your cells swell and burst.

This brine is toxic because it is saltier than the local ecosystem is able to tolerate, and can displace seawater forming pools that hang around.

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Grapesoda5k t1_isp6kik wrote

Not in this case. You're making parallel arguments based on nothing.

Not one source has supported your argument in the desalination discussions.

https://news.mit.edu/2019/brine-desalianation-waste-sodium-hydroxide-0213

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ArmadilloReasonable9 t1_isp84xj wrote

There was no mention of toxicity in that article? Dissolution of NaCl in H2O produces Na+, Cl-, OH- and H+ ions. These can form sodium hydroxide and hydrochloride acid. The article supports what I said saying that careful discharging into the ocean is safe if properly managed.

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Grapesoda5k t1_ispbwq1 wrote

"If" isn't a response you can trust from a corporation.

And notice none of the solutions being done say this stuff is safe for human consumption.

If it was the waste wouldn't be an issue.

So it's not a matter of concentration.

And needing careful consideration in handling the bi-products argues its not just hi-test salt.

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tiregroove t1_isntu0k wrote

Did you not read the link? Desalinization plants create overwhelming unsustainable and TOXIC levels of salt, LITERALLY the size of Florida EVERY YEAR, with nowhere to put it all, on a level that's killing marine life.
More than half from Saudi Arabia.

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hiraeth555 t1_isnwy9t wrote

Make those lamps out of the excess salt and give them out for free

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SuspiciousStable9649 t1_isnyb2h wrote

Color it sky blue and call it ‘Arabian Salt’.

Edit: but seriously is cheapest to just wash it back out to sea.

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Uptown-Dog t1_isox16o wrote

Yeah, we know that's the cheapest option and so that's why everyone does that rn.... Except it kills marine life and creates dead zones where that's done because it's too salty for anything alive.

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Garbage_Wizard246 t1_isp1msu wrote

Salt can be used to fuel nuclear reactors and an easy material for batteries. There are other solutions people

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Uptown-Dog t1_isp2a08 wrote

I'm all for other solutions. But AFAICS no one doing desalination is getting down to pure salt as it's not cost effective. Rather they stop at "toxic brine". Otherwise I don't see why they couldn't just create and pack all the bricks of salt in a storage setup and work from there.

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Garbage_Wizard246 t1_isp5knm wrote

It can be subsidized if the correct supply chain is set up following it. I'm hoping salt batteries take off soon and if we have good infrastructure they can compliment each other in the bid to go green

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Tlaughs t1_isqwgpy wrote

Recent research suggest this isn't true if it's pumped out to blue ocean it dilutes to nontoxic levels extremely quickly

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Uptown-Dog t1_isqx2u5 wrote

Do you have a link available? Also, how far out qualifies as "blue ocean"? It would almost certainly be contingent upon currents too, as otherwise it would build up? I would also be curious as to how rigorous the science is, as opposed to "we pushed it out of sight and we're bad enough at detecting life there that no one is able to call us out at this stage for killing things there".

Which isn't to say that I'm not encouraged to hear that - and maybe there's an argument to be made that life close to shore is more important than life further out?? - but it needs to be sustainable.

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Tlaughs t1_isvuorj wrote

I don't, it came up months ago in a similar post to this one, and they had sources which I do not.

It might very well have been the latter part of what you said, marine life is overwhelmingly close to shore or other landmarks like reefs/wrecks/vents. When it is pumped out into open ocean the currents can fully reach and disperse it, with a fraction of marine life within the (reduced) zone in which the salts are toxic. It all came from the ocean, and despite the massive volumes that are desalinated, it's not a meaningful increase in concentration.

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youritalianjob t1_iso9r42 wrote

You act like the amount of salt we extract for consumption and other uses isn’t a large amount.

Currently we extract about 290 million metric tons a year.

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OfLittleToNoValue t1_isnyjxe wrote

Global warming is raising sea levels. Desalinate the water and drink it to lower sea level. Put salt where the glaciers were. Easy.

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CroatianBison t1_iso5my2 wrote

Salt is white, glaciers are white, I see no flaw with this plan. Nobody will notice the difference

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smohan t1_isofftx wrote

I wonder of the color itself might help, cos I remember reading that reflection of solar rays by ice caps helps lower temperature.

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Snuffy1717 t1_isodymn wrote

Also, we all know that salt makes ice colder so in doing this we've solved the ice melt problem!

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ArmadilloReasonable9 t1_isp3tze wrote

It’s sea water with a 15% higher concentration of salt, the brine just needs to be well dispersed and released slowly and it won’t cause any issues to the environment. That article was a mess.

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Holden_SSV t1_isqem2i wrote

Snow removal contractor here. We make our own salt brine for pre treatment of ice storms or even snowfall. 18% is our good to go number.

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ArmadilloReasonable9 t1_issdv9o wrote

18% salt by weight? This stuff is 5% salt by weight, 15% higher than sea water. Sadly there probably wouldn’t be many desalination plants near areas that have to salt their roads.

There are definitely uses for it but they’re all pretty impractical until we’ve got excess renewable energy capacity to pump it further or use electrolysis to separate the different ions.

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Strazdas1 t1_isswq5l wrote

noone needs to salt thier roads. Its a terrible practice that destroys cars, shoes and plantlife that this brine gets onto. Just use small gravel like norway does.

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Strazdas1 t1_issweva wrote

how about, and i know this is a radical thought, put the salt back where you pumped it from?

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Grapesoda5k t1_isoac8b wrote

Sell it to places that process brine.

It can be be used to produce sodium hydroxide and hydrochloric acid.

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BeachesBeTripin t1_isp7btz wrote

Gotta put our nuclear waste in something salt is great in an area that will never get rain.

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FwibbFwibb t1_iswne0g wrote

> Great now what do we do with all the excess salt?

Saran wrap it into blocks and dump them in the desert.

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colossalpalladin t1_ispd9zq wrote

Well, thousands of studies like this are being published on an yearly basis. Right now the problem is not making highly permeable membranes, but it is making highly selective membranes (such as those achieving Li+/Na+ separation). This study is not an advancement in the field of membrane desalination, but an advancement in the field of materials sciences.

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bellypoint t1_isq5tnw wrote

Anyone know what happened to that technology with hair that was used to take up salts and oil?

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twohammocks t1_isp8k2r wrote

What would be interesting is to use that salt to coat the inside of abandoned mines, and then we would have a great spot to store hydrogen gained via excess solar or wind power. Then when water is too scarce, burn that hydrogen for water and energy, or even fill up airships for floatation power. I have links for the above if interested.

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Grapesoda5k t1_isoa9u8 wrote

This is your last hope California.

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