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Comment by heimatau | Hacker News Reader

HN community seems to really like desalination. Various innovations seem to hit the FP occasionally.

I'll say this to the general sentiment. My 9th grade chemistry teacher say 'your generation will face two major problems: xxxxxx and water'[1]. He's been a sage in my life, retired for about 1.5 decades.

I say all this to attempt to say that 'this is refreshing' that this community understands that we are in an impending crisis of water. Onward! :)

[1] - I'm a millennium and I won't reveal 'xxxx' because I'm not trying to incite anger but he was correct about 'xxx'.

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My thesis in grade school thesis from ~17 years ago was that the two most important problems to by solved in my lifetime were going to be low cost, low emission and low land use energy production and efficient information processing and communication.

I think desal is much less of a problem if we had a cheap, clean, and reliable source of energy to power it such as nuclear.

Quality of life is strongly correlated with energy intensity.

I'm not entirely sure how but in the past two years, I've become a believer in the capitalism structure for the markets and that it's able to solve any given problem (including what you're saying). Capitalism just needs to get nudged into a direction and the solutions will be a product of markets.

To elaborate my point, through government subsidies: - American has seen massive production of food (so much that we waste an insane amount every year) - Massive creation with minimal resources (via petrol innovation; even if y'all don't like it, it was an easy win for society and we're living with the second order effects) - Vehicle fuel efficient rise - Green revolution is almost profitable without government subsidies.

I'm not an economist but the game theory does seem to playout in such a way, for the past century, to confirm 'we'll find a way, given a nudge in the right direction'.

You should check out the Decouple podcast :)

https://podcasts.apple.com/us/podcast/decouple/id1516526694

Why do the x's keep getting fewer? Is the crisis a lack of x's?

> Why do the x's keep getting fewer? Is the crisis a lack of x's?

Yeah. I ran out of ink.

We don't have a water crisis. We have a clean energy one. With abundant energy we could simply boil sea water to get drinkable water. The biggest problem of the various desalination methods are their energy cost, and this method to reprocess the brine is meant to offset it by extracting commercial value from the desalination residue. While it's great to make desalination commercially viable, we also need to remember our energy needs will not drop.

I have the nagging feeling that the "commercial" part is what we'll need to solve if our species is to survive long term. In some matters, whether its commercially viable should not be a concern.

> With abundant energy we could simply boil sea water to get drinkable water.

That still leaves you with either solid salt that needs to be disposed of (preferably, somewhere where it can't eventually leach out into groundwater) or highly concentrated brine which will kill anything near it.

How much waste salt would we have compared to the amount of salt that we are going out of our way to extract or mine already? I mean, I literally pay money for sea salt at the grocery store.

How much salt do you use in a month? How much water do you drink?

That's not really a fair comparison. There's easily 25x as much water vs salt in the ocean, and a 10x higher fraction of water usage is residential than salt usage. The break-even point you're pointing to is closer to 250:1, not 1:1.

That's fair enough, but I still doubt you use 1/250 of water in salt, even when you're cooking. If you add things like showering, washing clothes, and lawn care, it's not even close

The numbers I gave did include factors like showering.

Edit: I do think that you use more than 1/250 salt vs water in cooking though (whether by mass or volume). By mass that's around 1tsp of salt per 6.3 cups of water, and soup recipes for example will often call for that much extra salt on top of whatever is already in the other ingredients you're using.

Edit: Individual recipes are probably the wrong way to look at that. It's recommended to eat under 1tsp of salt (actual usage is higher in the USA) and drink over 10 cups of water each day, so whatever combination of food/beverages you're taking in you still wouldn't quite hit that crude 1/250 threshold.

Salt is also useful for things other than eating it, and more of those uses may be cost-effective if salt were more plentiful.

Sea salt contains microplastics. You should seek out mined salt.

Or we could find a way to remove them from, say, the brine.

Just put it back from whence it came. The extracted water doesn't exactly leave the environment, it will find its way back into the oceans anyway.

If the excess brine is diffused over a wide enough area or as is often the case, the outlet of an estuary, local disruption is minimal and global disruption is exactly zero.

"highly concentrated brine which will kill anything near it."

That sounds a bit dramatic, for salt in water, don't you think?

Sure, it is not a enviroment, live can prosper and it kills most living things, that would have to live in it, but it is also not deadly toxic, "killing anything near it" like your comment implies.

I've got karma to burn, so I'll come out and address the controversy straight on. xxxx is the rarity of Charizard in Pokemon Go.

xxx = Mass migration?

Depends on where you live, it is already happening. And it is sometimes caused by long droughts, actually.

Also another thing I hear a lot of hype about is Atmospheric Water Extraction, but as of now remains longway from being practical at scale.

xxx = pollution? energy?

edit: or a certain political guy?

xxx = misinformation

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