The Dirty Truth About Turning Seawater into Drinking Water

Post by dahfizz » Thu, Jan 17, 2019, 12:46 PM UTC

mcv wrote: post #59

endorphone wrote: post #30

Earlier quoted context omitted.

Just to be clear, "brine" isn't "salty water." It mostly is, and the additional chemicals they mention are already in the sea water, not that were added somehow in the process. It's just concentrated. That it's concentrated is a problem, obviously -- very high-saline water (e.g. brine) and concentrated toxins are a problem, and would cause environmental problems if just dumped. The most common way to deal with brine…

> the additional chemicals they mention are already in the sea water, not that were added somehow in the process. Are you sure? The article made it sound like they were added. If they're natural to sea water, simply diluting it with more sea water or possibly sewage that's headed for the ocean anyway, sounds like the obvious solution.

Post by rocqua » Thu, Jan 17, 2019, 12:48 PM UTC

mcv wrote: post #62

aphextron wrote: post #28

I’m surprised this article mentions nothing about energy. Practically all desalination in existence is powered by fossil fuels, with Israel and Saudi Arabia being the worst offenders. The only reason it’s even economically viable is the externalized cost of carbon emission. It’s simply not a long term tenable solution until this is addressed.

> Practically all desalination in existence is powered by fossil fuels, with Israel and Saudi Arabia being the worst offenders. Sound like really obvious places to use solar.

Post by peteretep » Thu, Jan 17, 2019, 12:51 PM UTC

mcv wrote: post #58

I admit I had not expected this to be a problem. The salt water comes from the sea, I'd expected it to be fine to release the salt back into the sea. But I understand that untreated, this extra-salty water would, in large amounts, become a current of its own that's significantly different from regular sea water. And apparently there are added chemicals in it that I suppose were necessary for the desalination process?…

Post by foxrob92 » Thu, Jan 17, 2019, 12:54 PM UTC

aphextron wrote: post #28

I’m surprised this article mentions nothing about energy. Practically all desalination in existence is powered by fossil fuels, with Israel and Saudi Arabia being the worst offenders. The only reason it’s even economically viable is the externalized cost of carbon emission. It’s simply not a long term tenable solution until this is addressed.

Post by Nasrudith » Thu, Jan 17, 2019, 1:07 PM UTC

beagle3 wrote: post #37

loudmax wrote: post #34

Earlier quoted context omitted.

Carbon emissions is a grave problem with existing desalination infrastructure, but this seems something that can be solved. I'd expect desalination to be well suited for opportunistic use of solar or wind power. Build up reserves of clean water when it's sunny or windy, then deplete those reserves when cheap spare energy isn't available. Of course this goes for new desalination plants. Whether there's political will…

Most desalination plants around the world are operating at 100% capacity all of the time, because that's what needed to avoid depletion of the reservoirs. To be able to "build up reserves" means that you have to build much higher capacity, but only use as much of it as clean energy allows - in today's world, this is highly uneconomical. If anything, the reserves to be built are energy reserves that allow water to be…