http://www.technologyreview.com/feature ... alination/
Technology Review had an informative article about the "Sorek" SWRO plant on the coast near Tel Aviv.
Sells water at 58 cents per cubic meter.
Reverse osmosis uses PRESSURE to squeeze salty water thru a membrane which won't let the salt pass.
It uses less energy than for example distillation. The water does not have to be evaporated.
One environmental problem to be handled is how you pump the concentrated salt brine back into the ocean. You have to disperse it so that it does not mess up the underwater environment.
Israel has 4 large desalination plants which together supply about 40% of municipal water.
This "Sorek" plant, built between 2011 and 2013 is the largest and most economical.
You might want to check it out.
Design and construction was by "Israel Desalination Enterprises" (IDE) and I saw another article where IDE was collaborating with a TEXAS agency on some kind of desalination project. Maybe just at the design stage. Texas has been suffering from a long drought (recently broken by torrential rains).
I'd like to know more about SWRO. You have to draw in sea water, and get rid of entrained solids, a kind of pre-purification, and then you squeeze out fresh water thru the "filter" and that leaves the salt in an EXTRA SALTY brine, which you have to get rid of. I don't know what fraction of the water comes out fresh and what fraction remains as the extra salty concentrated brine. It could be, for example, half and half. Whatever the fraction you have all this brine to get rid of.
If anybody has other informative links please post them. This is potentially a very interesting thing to know about.