I think the problem of salt is a much bigger problem than we realize it. It's toxic, you can't burn it for fuel, and you can't really do anything with it except store it. Are there other ways of disposing of salt without repercussions?
Or (this might seem crazy) considering Antarctic sea ice is melting at increasingly faster rates, which isn't good in itself - is that causing the water at the far south latitudes to be lacking in salinity? Would additional salt there provide for keeping the ecosystems stable for longer at least? Granted shipping would be another issue.
The former may require some free market ingenuity, the latter may require some ingenuity and some sort of goodwill on the part of some governments.
The challenge is how to understand and work with natural ecosystems well enough to not burden them with salt concentrations that harm them, and perhaps even to fit and enrich them.
* Problem 2: If dumped into the ocean, it increases the salt concentration (see: Middle East).
Disclaimer: Worked on some related projects on how to find a positive use for Brine.
The scale is the problem. At the end, you still end up with lots and lots of inorganic material, which is toxic for the environment.
But there's also industry that extracts the salt from the Great Salt Lake, via evaporation. This shows that, if you've got salt to dump somewhere, there's actually a market for that. (That is, if it's pure. Others pointed out the problem of chemicals added to the salt water to make it easier to process.)
http://buildingwithseawater.com/?myportfoliotype=the-salt-bu...
Or dilute it. The solution to pollution is dilution.
For a while. The scale of human population and our increased per capita resource usage starts to make that less often viable.
The salt comes from the ocean in the first place, and the water returns to the ocean relativly quickly. Unless something changes and we start to notably change the volume of water in the ocean, dilution is the only way to maintain the ocean chemistry. If we don't, then we would be reducing the salinity as the water returns without the salt.
The problem is that it isn't perfectly diluting, it's concentrating the salt in areas near the desalination plants, changing ecosystems and causing problems locally.
There's also the semi-related problem of salt that isn't from the ocean making it's way there, increasing the overall salt concentrations over time.
If we could find a way to use the salt from desalination (at least partially) somewhere else, then maybe we could help offset the "saltification" of the ocean and can more easily avoid destroying ecosystems around desalination plants. (it doesn't need to be an all-or-nothing solution, we could still dump some salt back into the ocean while keeping some out and used in other areas)
> But a less chattered-about problem is the effect on the local environment: The primary byproduct of desal is brine, which facilities pump back out to sea. The stuff sinks to the seafloor and wreaks havoc on ecosystems, cratering oxygen levels and spiking salt content.
> The primary byproduct of desal is brine, which facilities pump back out to sea. The stuff sinks to the seafloor and wreaks havoc on ecosystems, cratering oxygen levels and spiking salt content.
The issue is the dissolution process is slow enough that the salt has time to wreck havoc on the environment. And if you're taking river water or aquifer water to dilute the brine to a point near the local salinity why go through the whole desalination process to start with instead of using the water to dilute this byproduct?
It's easy to forget that at large scales the ocean doesn't really disperse things evenly. Surface salinity for example ranges from 30-40 g/kg across the surface of the ocean.
https://www.nasa.gov/sites/default/files/styles/full_width_f...