4 ms·

Desalination releases brine, and would even if you had free energy. It's a disaster for local sea life. You can either pump it back out to disperse it over a l

by mlsu 2y ago

Desalination releases brine, and would even if you had free energy. It's a disaster for local sea life. You can either pump it back out to disperse it over a large area, or release it and kill all local marine life. Pumping it back out to disperse it is extremely expensive because the brine is corrosive. You could evaporate the brine but that takes land area plus you have to have the infra to actually use the salt, purify it, etc. This all is a far bigger problem than the energy cost.

kylehotchkiss 2y ago
Too bad we don’t pump sea water to the desert, fill up a basin somewhere we don’t care so much about, let all the brine sit in evaporation pools, and power it all with local solar. Input from somewhere in Gulf of California and send the water to somewhere in imperial county away from the crops. We process Tijuana’s sewage free of charge so it seems reasonable we could ask Mexico to help us with a pipeline.
- mlsu 2y ago
  Desalinization at scale produces a LOT of brine. Like, way more than anyone needs. The evaporation pools would need to be gargantuan to service SoCal. State of California uses about 5maf of water (non-ag; with agriculture, much much more). That's is 6 cubic km of brine, per year. Say we service SoCal, that's 3 km^3 of brine per year... The entire salton sea is 7km^3. And that is only residential/commercial use like drinking water. Which basin don't we care about? The desert is not "outside the environment" especially at that scale. There are critters living even in the most godforsaken areas of Anza Borrego. We are talking an environmental catastrophe, something like the Aral Sea.
  - JohnMakin 2y ago
    plus california has the literal example of the salton sea ecological disaster here to draw upon. like, brine is a well known and difficult problem to deal with at scale. it isn’t just the massive amounts of salt, it’s all the concentrated metals as well.
lesuorac 2y ago
Isn't the whole reason it releases brine is because energy isn't free? You'd just run thermal desalination to a 100% reaction of salt water = salt + water and then have no brine and a bunch of salt to sell no?
- mlsu 2y ago
  Well, the energy isn't free, so you'd definitely be doing osmosis and making brine (osmosis is like 1/5 the energy compared to distillation). But even if it were and you could run thermal desalinization. It's a LOT of salt. And the salt is not pure -- it's "salt" in a chemical sense, not a table salt sense, which you'd then have to purify, removing heavy metals, pollutants, etc. At rates of desalination that would service an appreciable amount of drinking/household water, you would no longer be selling the salt, you'd be disposing of it. Because there would be too much of it to sell. The honest to god ONLY place you can naturally dispose of a lot of salt is the ocean, for the same reason that its there in the first place.

by mlsu 2y ago

kylehotchkiss 2y ago

Too bad we don’t pump sea water to the desert, fill up a basin somewhere we don’t care so much about, let all the brine sit in evaporation pools, and power it all with local solar. Input from somewhere in Gulf of California and send the water to somewhere in imperial county away from the crops. We process Tijuana’s sewage free of charge so it seems reasonable we could ask Mexico to help us with a pipeline.

mlsu 2y ago
Desalinization at scale produces a LOT of brine. Like, way more than anyone needs. The evaporation pools would need to be gargantuan to service SoCal. State of California uses about 5maf of water (non-ag; with agriculture, much much more). That's is 6 cubic km of brine, per year. Say we service SoCal, that's 3 km^3 of brine per year... The entire salton sea is 7km^3. And that is only residential/commercial use like drinking water. Which basin don't we care about? The desert is not "outside the environment" especially at that scale. There are critters living even in the most godforsaken areas of Anza Borrego. We are talking an environmental catastrophe, something like the Aral Sea.
- JohnMakin 2y ago
  plus california has the literal example of the salton sea ecological disaster here to draw upon. like, brine is a well known and difficult problem to deal with at scale. it isn’t just the massive amounts of salt, it’s all the concentrated metals as well.

lesuorac 2y ago

Isn't the whole reason it releases brine is because energy isn't free? You'd just run thermal desalination to a 100% reaction of salt water = salt + water and then have no brine and a bunch of salt to sell no?

mlsu 2y ago
Well, the energy isn't free, so you'd definitely be doing osmosis and making brine (osmosis is like 1/5 the energy compared to distillation). But even if it were and you could run thermal desalinization. It's a LOT of salt. And the salt is not pure -- it's "salt" in a chemical sense, not a table salt sense, which you'd then have to purify, removing heavy metals, pollutants, etc. At rates of desalination that would service an appreciable amount of drinking/household water, you would no longer be selling the salt, you'd be disposing of it. Because there would be too much of it to sell. The honest to god ONLY place you can naturally dispose of a lot of salt is the ocean, for the same reason that its there in the first place.