The American Interest
Analysis by Walter Russell Mead & Staff
Human Ingenuity Set To Conquer Water Crisis

Humans may never have to worry about the supply of fresh water again. The University of Texas at Austin reports that some of the university’s scientists have found a new way to desalinate sea water, potentially easing concerns over one of the crises facing human civilization we’ve been told is just around the bend:

The new method requires so little energy that it can run on a store-bought battery. The process evades the problems confronting current desalination methods by eliminating the need for a membrane and by separating salt from water at a microscale [...]

To achieve desalination, the researchers apply a small voltage (3.0 volts) to a plastic chip filled with seawater. The chip contains a microchannel with two branches. At the junction of the channel an embedded electrode neutralizes some of the chloride ions in seawater to create an “ion depletion zone” that increases the local electric field compared with the rest of the channel. This change in the electric field is sufficient to redirect salts into one branch, allowing desalinated water to pass through the other branch.

This new method isn’t fully proven yet: so far, the scientists involved have used the tech to reach 25 percent desalination and they need to reach 99 percent for it to become usable. And there are some questions about the amount of energy this process would take. But even if this particular tech peters out, sooner or later someone will invent a comparable technology that succeeds at the same goal. Indeed, other companies are already at work on desalination products of their own.

One of the biggest feeders of Malthusian fears in recent years has been the body of literature predicting the threat to our fresh water supply. Book after book after book has described the water crisis facing the planet. History has shown that human ingenuity has allowed us to overcome challenges thrown at us by geography, the elements, and alleged overpopulation. Could it be that this time it may be no different?

[Image of African Well from Hector Conesa / Shutterstock]

Published on July 13, 2013 2:00 pm
  • Pait

    While it is true that human ingenuity has allowed us to overcome challenges thrown at us by geography, it is not true that human ingenuity has allowed us to overcome ALL challenges thrown at us by geography. We may need some ingenuity indeed to avoid going the way of the Easter Islanders.

  • Russell Snow

    Julian Simon wrote about this in his book the ultimate resource.

  • crocodilechuck

    Who writes this stuff? Walt, do you have the slightest understanding of the second law of thermodynamics?

    ps remedial reading: https://en.wikipedia.org/wiki/Perpetual_motion

  • Jim__L

    If I had to guess…. neutralizing the chloride ions may cause the positively charged sodium ions a given packet of fluid to repel one another to the point that the population of sodium ions in the packet is significantly reduced.

    I’m not sure what happens to the chloride ions (is there a risk that they might plate out on an electrode somehere?), and frankly I’m not absolutely certain whether the above paragraph would actually work, but it sounds like it might be at least somewhat plausible.

    The desalinization rate (which the article emphasizes is very low) is probably proportional to the amount of power you pump in, keeping this legal under Thermodynamics. The important bit seems to be an absence of moving parts, and (possibly) an absence of consumables in the process (though the brine has to go somewhere.)

    Interesting stuff. I wish they’d publish more of the technical details.

  • bigfire

    Have no fear. Environmentalist will put a stop to this. THEY CANNOT allow those poor people to get out of their poverty. That’s simply against the natural order of things.