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New method turns ocean water into drinking water, without waste

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Re: New method turns ocean water into drinking water, without waste

#201

Post by Enginerrrd »

lazide wrote: post #69
Enginerrrd wrote: post #64

Earlier quoted context omitted.

Municipal waste water is a much cheaper way to get desalinated water in the first place though.

except for the pharmaceuticals anyway

That’s been a solved problem, engineering-wise, for a while.

The advanced treatment stages take care of it. Between UV, ozone, and nanofiltration, etc. we can remove the pharmaceuticals.

Actually the problem is the water comes out too pure out of a well designed water reuse system, to the point where the mineral content can be too low and you need to add some back in.

Re: New method turns ocean water into drinking water, without waste

#202

Post by analog31 »

ceejayoz wrote: post #48
xyzzyz wrote: post #44

Earlier quoted context omitted.

Brine is very easy to dispose of: you just pump it back to where it came from. Solid crystalline salt, on the other hand, is a hassle.

> Brine is very easy to dispose of: you just pump it back to where it came from. Easy, but not necessarily good for the spot you're pumping concentrated salt back into.

Someone tell me why this is stupid, which it probably is: Put the desalination plant on a tanker ship and let it do its duty out in the middle of the ocean, then cruise back to port and dispense the water.

Re: New method turns ocean water into drinking water, without waste

#203

Post by __MatrixMan__ »

xp84 wrote: post #141
ashdksnndck wrote: post #95

Earlier quoted context omitted.

If you use fat pipes that go a decent distance from shore, diluting your brine with ocean water, you’ll have a negligible impact on the ocean. The problem is if you dump lots of brine in shallow waters. Old designs did have that flaw, but it’s not that difficult to design around this constraint now that we know about it. IMO this is an issue where NIMBYs are using environmental concerns as a smokescreen to block new…

I can probably be convinced pretty easily with some evidence of that, but you’ll never convince the contingent who is convinced it’ll kill sea life at any concentration or location, so, being able to shut them up by saying “we have no wastewater, we load rail cars with crunchy salt and use it for stuff” still has value.

I wish we could reimagine carbon credits to that degree of stringency. You offset a kg of carbon emissions? Let's see that kg.

Re: New method turns ocean water into drinking water, without waste

#204

Post by boxed »

wizzwizz4 wrote: post #32
boxed wrote: post #18

Earlier quoted context omitted.

I mean.. we really want to permanently desalinate the ocean somewhat too so putting the brine back seems kinda stupid. Put it on land, let it dry, sell some as table salt and dump the rest into abandoned mines.

Excellent idea! The largest abandoned mines I'm aware of are salt mines, which… hang on.

Yea, that's one of the problems. We're literally digging up salt AND the mountains are being eroded to add more salt. The Earth is getting anti-terraformed and we're speeding it up. (Although obviously the fossil fuel situation is a much closer and worse problem)

Re: New method turns ocean water into drinking water, without waste

#205

Post by xhkkffbf »

westurner wrote: post #192
ajb wrote: post #4

There is a fundamental minimum amount of energy needed to desalinate: you can't take less energy to do it,than you could gain back (from osmotic pressure) if you allowed the desalinated water to expand a cylinder containing the residual brine. This is large. This paper is a thermal method, so it doesn't have an electricity input, but to justify their efficiency claim, they should really compare against what you could…

ScholarlyArticle: "Extreme salt-resisting multistage solar distillation with thermohaline convection " (2023) https://www.cell.com/joule/fulltext/S2542-4351(23)00360-4 .. https://scholar.google.com/scholar?cites=7551078272963689346... "Desalination system could produce freshwater that is cheaper than tap water" (2023) https://www.eurekalert.org/news-releases/1002811 ScholarlyArticle: "Highly efficient and salt reject…

I remember the MIT press release. I wonder if they've found any commercial success.

Re: New method turns ocean water into drinking water, without waste

#206

Post by blackoil »

patates wrote: post #197
ajb wrote: post #4

There is a fundamental minimum amount of energy needed to desalinate: you can't take less energy to do it,than you could gain back (from osmotic pressure) if you allowed the desalinated water to expand a cylinder containing the residual brine. This is large. This paper is a thermal method, so it doesn't have an electricity input, but to justify their efficiency claim, they should really compare against what you could…

I always thought that if separating water and salt were easy, our bodies would have evolved to do it so that we'd be able to drink sea water and be fine. It must have been so expensive that searching for fresh water was worth it or there were plenty of fresh water that it was never a evolutionary pressure. Evolving kidneys capable of concentrating urine beyond 3 something percent concentration (sea water) perhaps req…

Salt water fish can process sea water, no point in evolving for saltier brine if you have oceans of 3% water.

Re: New method turns ocean water into drinking water, without waste

#207

Post by Tagbert »

patates wrote: post #197
ajb wrote: post #4

There is a fundamental minimum amount of energy needed to desalinate: you can't take less energy to do it,than you could gain back (from osmotic pressure) if you allowed the desalinated water to expand a cylinder containing the residual brine. This is large. This paper is a thermal method, so it doesn't have an electricity input, but to justify their efficiency claim, they should really compare against what you could…

I always thought that if separating water and salt were easy, our bodies would have evolved to do it so that we'd be able to drink sea water and be fine. It must have been so expensive that searching for fresh water was worth it or there were plenty of fresh water that it was never a evolutionary pressure. Evolving kidneys capable of concentrating urine beyond 3 something percent concentration (sea water) perhaps req…

It’s mostly that it takes energy. If fresh water is we drink that. There aren’t a lot of places where only salt water is available so, for most animals, it isn’t worth it to have evolved a way to extract water from salt water.

Animals in the ocean of course do live without fresh water. Some of them just live off of water extracted directly from their food or from metabolizing that food, which produces water. Some animals have specialized cells that excrete salt so that can take in salt water and separate out the salt.

Re: New method turns ocean water into drinking water, without waste

#208

Post by collingreen »

xp84 wrote: post #143
shermantanktop wrote: post #103

Earlier quoted context omitted.

Hey, it's free viagra, prozac, progesterone and multivitamin supplements, all in a glass.

There’s some fat fish out there, I hope we can get those guys some Ozempic too

Democrats intentionally killing the fishing industry by giving fish free glp1s and cocaine with your tax dollars!

Re: New method turns ocean water into drinking water, without waste

#210

Post by jazzyjackson »

dyauspitr wrote: post #160
AlexandrB wrote: post #112

Earlier quoted context omitted.

The Saudis aren't "daring" with megaprojects. They're fucking[1] stupid[2]. Saying their megaprojects are "daring" is like saying I'm "daring" for claiming I'm going to build a catapult that will launch me to the moon. [1] https://en.wikipedia.org/wiki/Trojena [2] https://en.wikipedia.org/wiki/The_Line,_Saudi_Arabia

That’s what daring means. You try things that do not guarantee success. I remember a decade of people shitting on Dubai for all of the crazy projects it was building. It really paid off for them (pre Iran war). They made something out of nothing and still are. What’s stupid about a kilometer high tower? It’s fucking awesome.

Speaking of shitting on Dubai have they built any plumbing yet or are they still trucking their sewage out of town?
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