• Mouhamed_McYggdrasil [they/them,any]
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    edit-2
    4 years ago

    ok, so I've got a question: From what I've read, you can desalinate seawater via reverse osmosis with 1000PSI of pressure against the semi-permeable membrane. At fist that seemed like a shit ton, but them I remembered each meter of water column gives an additional 1.45PSI or so.. That means if you go out to where the ocean is 700m deep, you should be able to desalinate water just with the pressure differential the water column gives. Could't you just put a big membrane on the bottom of the ocean, and have an undeground pipeline routing it back to land, where it could either be stored in some kind of reservoir or just have people drill wells down to pump it up? The logistics might be fucky, but I just looked some shit up and the deepest oil well is 2km deep. I guess keeping the pressure on the other side of the membrane at 1atm could be tough , I could see a hole in the membrane rupturing and then it floods and there's no pressure differential. Hold on a sec, couldn't you just build like a big cube (or sphere) of membrane that holds millions of liters of water, tie a big rock to it so it sinks down to the level where there's enough pressure for reverse osmosis, wait for it to fill up, and then haul it back up from the ocean floor, and have yourself a big bubble of fresh water for agriculture or drinking or waterparks or whatever? Like just get some old submarine, blast a hole in its hull, stretch the proper kind of membrane around the hole, and then have it sink to 700m, where it'll take on water like any submarine that got a hole blown in it would (except this one has to go across a semi permeable membrane, so even though its a SEA-water, it'll be FRESH-water filling up the sub), and then have it surface? I suppose you'd need to build waterproof electronics and engines and stuff so it can function while its flooded, but it can't be that hard, right?