Posted by speckx 1 day ago
I suppose you could water down the ocean water it’ll was drinkable, or like just add half a teaspoon of sea water to a cup or drinking water.
Buy all work done eventually decades in to waste heat.
...except for the huge piles of salt.
If the salt was not waste, surely people would already be extracting it from the brine and the existing methods would also be "without waste".
I would like to read more about this from an authoritative source.
https://www.frontiersin.org/journals/marine-science/articles...
https://www.sciencedirect.com/science/article/abs/pii/S14635...
The San Francisco bay has to be actively managed for similar reasons. It's a large body of water with a narrow outlet, fed by a river system from which much water is captured. If too little water comes in from the Sacramento River, the delta will turn to salt water. Managing that is what the Bay Model, mentioned recently, is for.
@GP: Instead of a plain complain, it's better to get an interesting discussion to write an explanation of why the post makes no sense, or instead find the good debunking comments and upvote them (there are two or three good comments near the top now).
I try to be that guy (personal hall of shame https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu... ) but life is too short and I have other things to do IRL.
Also, it's not my area. It's close enough to have a good guess, but in this case for me it's better to let someone else give an accurate reply.
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Back to this post:
It obviously makes no sense. You have salt water, you extract the water, you have to get rid of the salt. Why waste time reading the details? [There are some interesting technical ideas about new surfaces, more on this later.] Reading the details their brilliant idea is to make salt cubes and sell them. So there is no waste!
When you get rid of the salt using brine, it's easier to transport and dilute the liquid. With solid salt you must scrape it form your high tech surface (without scratching it?!) and now the solid salt is difficult to transport. Also, to sell it you must purify it because it will include nasty things like crabs legs and sea smell.
Once you extracted the 99% of the water, it's difficult to extract the other 1% of the water because it's saturated solution with a low osmotic pressure, vapor pressure and a high boiling temperature. Also, water inside the block of salt is difficult to extract, and you must crush the small blocks.
Salt production is done in big salt lakes areas, where energy is "free". I like to consider it like a huge natural solar panel. You get heat for "free" and dry wind for "free". You must pay for them in an industrial facility. Also, the normal process still requires a lot of manual labor of guys/gals with [mechanical] shovels to makes piles of salt, wait, turn it a few times, wait, turn it a few times, wait, ... and you now have a nasty salt that you still have to purify to be able to sell it.
So they will get salt that is too expensive to sell, and too much of it to flood the market, and if you put it in the garbage can it will be classified as [industrial] waste.
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The technical part looks interesting, but it's on the bottom of an unrealistic title and first paragraph. The interesting part is about the new surface with nano details and titanium oxide that absorbs Lithium. It sound interesting and they published it so there is some validation of the claim, but after the nonsensical first claims I'd want to take a look at the feasibility details.
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>> Can we please ban university press releases
> Why?
I work in an university and I expect technical accuracy from the press department of an university. We want people to give us money in exchange of doing real and interesting things. We want people to trust the medical doctors when they give health advice, or a lot of other specialist about other public policies.
A lot of press release of the universities have a lot of exaggerations, burning the trust of the people. Before opening one here, I like to guess what is the real result and what is the bullshit part. I think that a complete ban of university press release here is too much, but I understand why the GP is annoyed.
i'm hoping it doesn't scale, honestly.
You're not worried? If it's for batteries? For sure they'll extract whatever they can.
(I checked, some deposits are old lakebeds like https://en.wikipedia.org/wiki/Salar_de_Uyuni and others are igneous.)
It's also possible - true, I bet - that all the car batteries and storage batteries 8 billion people could possibly use are equivalent to only a tiny fraction of all the lithium in the ocean, but it would be harder arithmetic to confirm that, as well as being irrelevant on account of land-based mines existing.
That still means there's billions of tons of lithium in the seas, though.
> The brine byproduct wreaks havoc on sea life when it’s deposited back into the ocean by raising the salt level and lowering oxygen in the water.
Managing return of concentrated brine should be entirely tractable in the literal ocean.
Ships (with long submerged pipes) would be prone to weather events and generally less reliable than an installed pipe. Perforation would be prone to clogging from build up so a nonstarter I would expect. Adding flex tubing and a relocation robot would be a maintenance headache as well. Not sure there is an easy optimization.
As for surface life, I'm no oceanographer, but is that really the most vulnerable place? The surface is where fresh water rain meets the ocean, so that would dilute the salinity during storms. However, there's nothing to say that another pump couldn't be pulling from the ocean and mixing the brine into that so it's diluted before and not just pouring brine straight into the ocean
Regardless, it is totally possible to reintroduce the brine back to the ocean in a way to not be a shock to the local area. We have just chosen to make it harder on ourselves for some illogical reason.
Alternatively, in the absence of sensible regulations a cutthroat operator devoid of ethics constructs a plant that dumps concentrated brine in the immediate vicinity because that's the cheapest approach. Then reactionary elements raise talking points about environmental damage and pretend that it's a difficult problem to solve. Business as usual.
It’s obvious you can safely put salt back into the ocean with enough dilution. I bet a middle schooler could design a system to do it.