26 votes

Desalination system could produce freshwater that is cheaper than tap water

9 comments

  1. [5]
    BeanBurrito
    Link
    I've seen things in the news that states that large amounts of waste salt/sludge is a major problem. What to do with it, where to put it. This design takes care of the carbon footprint, but not...

    I've seen things in the news that states that large amounts of waste salt/sludge is a major problem. What to do with it, where to put it.

    This design takes care of the carbon footprint, but not the issue of the waste generated.

    7 votes
    1. Pioneer
      Link Parent
      Aye, any of these processes is going to cause these types of toxic sludge problems due to the removal of the salt. Does however make me wonder if there's an application where said material can...

      Aye, any of these processes is going to cause these types of toxic sludge problems due to the removal of the salt.

      Does however make me wonder if there's an application where said material can store thermal energy? Like non-lithium static batteries or something of the ilk.

      6 votes
    2. [4]
      Comment deleted by author
      Link Parent
      1. [3]
        BeanBurrito
        Link Parent
        I'm not an expert. I think ocean life depends on the ocean being a particular salinity. Then there is the carbon footprint and cost of transporting the salt/sludge further out into the ocean for...

        I'm not an expert.

        I think ocean life depends on the ocean being a particular salinity.

        Then there is the carbon footprint and cost of transporting the salt/sludge further out into the ocean for dumping.

        4 votes
        1. demize
          Link Parent
          Fortunately, the ocean is very big. We routinely and continuously dump unbelievable amounts of other waste into the ocean, and because the ocean is so big (and thanks to ocean currents) it has...

          I think ocean life depends on the ocean being a particular salinity.

          Fortunately, the ocean is very big. We routinely and continuously dump unbelievable amounts of other waste into the ocean, and because the ocean is so big (and thanks to ocean currents) it has effectively no impact on the ocean as long as the rate at which we do it is low enough (and that's not very low!). Desalination probably won't be much compared to, say, all of the wastewater from a city that dumps their wastewater into the ocean, especially since it's just concentrating what's already in the water.

          Then there is the carbon footprint and cost of transporting the salt/sludge further out into the ocean for dumping.

          You can just mix it with more ocean water and pipe it back into the ocean. If you're already building one pipe to extract water, doesn't take much more to build another pipe to return it.

          6 votes
        2. skybrian
          Link Parent
          The oceans vary in saltiness. From Wikipedia: Apparently climate change is making the salty parts saltier. Large desalination plants make brine that can cause local environmental damage if it...

          The oceans vary in saltiness. From Wikipedia:

          Salinity will be higher if evaporation exceeds precipitation, as is sometimes the case in tropical regions. For example, evaporation is greater than precipitation in the Mediterranean Sea, which has an average salinity of 38‰, more saline than the global average of 34.7‰.[114] Thus, oceanic waters in polar regions have lower salinity content than oceanic waters in tropical regions.

          Apparently climate change is making the salty parts saltier.

          Large desalination plants make brine that can cause local environmental damage if it isn't diluted enough. It depends on how the outtakes are designed. The brine can be mixed with seawater and piped far offshore. I'm no expert either, but I'd guess this would be mostly a capital cost (building the pipes). Maintaining anything in seawater is difficult, though.

          5 votes
  2. [3]
    talklittle
    Link
    It's an iteration on a previous design by the same team publicized in 2020. Interestingly there appears to be at least one other independent desalination project also coming out of MIT:...

    The researchers estimate that if the system is scaled up to the size of a small suitcase, it could produce about 4 to 6 liters of drinking water per hour and last several years before requiring replacement parts. At this scale and performance, the system could produce drinking water at a rate and price that is cheaper than tap water.

    It's an iteration on a previous design by the same team publicized in 2020.

    Interestingly there appears to be at least one other independent desalination project also coming out of MIT: https://news.mit.edu/2022/portable-desalination-drinking-water-0428 - Seems one is from MIT's Device Research Laboratory, the other coming out of their Research Laboratory of Electronics.

    6 votes
    1. [3]
      Comment deleted by author
      Link Parent
      1. cfabbro
        (edited )
        Link Parent
        Interestingly, Merriam-Webster actually have it listed as an alternative spelling of "fresh water". https://www.merriam-webster.com/dictionary/freshwater As does wiktionary:...

        Interestingly, Merriam-Webster actually have it listed as an alternative spelling of "fresh water".

        https://www.merriam-webster.com/dictionary/freshwater

        fresh water - 2 of 2 - noun
        or less commonly freshwater

        As does wiktionary:
        https://en.wiktionary.org/wiki/freshwater#Noun

        So it may not be totally incorrect usage.

        3 votes
      2. ix-ix
        Link Parent
        I have to ask, how much does it matter? I presume you understand what they are saying. So does it matter that they don't have perfect form? I don't want to sound hostile or anything like that, but...

        I have to ask, how much does it matter? I presume you understand what they are saying. So does it matter that they don't have perfect form? I don't want to sound hostile or anything like that, but never understand the need to call out some perceived grammar issue that does not impact anything.

        2 votes
  3. [2]
    Comment removed by site admin
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    1. sparksbet
      (edited )
      Link Parent
      This research was developed at MIT though? The authors on one of the other desalination papers were professors and postdocs at US institutions and one guy from DEVCOM who weren't even ethnically...

      This research was developed at MIT though? The authors on one of the other desalination papers were professors and postdocs at US institutions and one guy from DEVCOM who weren't even ethnically Chinese -- most of the authors were ethnically Korean. Why is the paper with Chinese co-authors less trustworthy -- especially when both have co-authors from MIT? I can't think of an explanation for this comment that isn't just straight-up racism. The fact that MIT partnered with a Chinese university for a project doesn't magically invalidate all results.

      10 votes