MIT has created a filter-free water desalination process that relies on electrical shockwaves

Shock electrodialysis desalination - fracking pond toxic wastewater
The dwindling availability of potable water for communities around the world has inspired many fresh takes on water purification. An MIT chemical engineering team has developed a new desalination process that separates salt from water using an electrically driven shockwave. Constantly pushing apart pure water molecules and the larger atoms of sodium and chlorine in a single stream of water makes it possible to repurpose salt water and even toxic wastewater for drinking purposes, without the long-term sustainability obstacles of traditional desalination processes.

The technique, known as shock electrodialysis, is unique because it’s a “membraneless separation system”. Traditional desalination processes typically use reverse osmosis or electrodialysis to pull apart water molecules and salt particles on either side of a one-way separation membrane. Filtration systems that require this kind of separation can be extremely ineffective as the membranes become clogged. Even the unclogging solutions proposed for membrane separation systems, like boiling, require large amounts of energy to be expended on a regular basis.

MIT shock electrodialysis desalination demonstration chemistry

Chemical engineering and mathematics professor Martin Bazant and his team of student researchers use shock electrodialysis to circumvent issues like clogging in a system that, superficially, looks very similar to traditional desalination techniques. Because their system still requires some physical separation of water molecules and salt particles, Bazant and his team use a porous material composed of many tiny glass particles, called a frit. Either membranes or electrodes can be used to surround the system, so that when an electric current is applied, water divides itself into two regions of the stream; one with purified water and one with salt water.

When the electric current applied to the system is strong enough, it generates a shockwave that immediately and precisely divides fresh water from salty water. Even when shock electrodialysis is applied with the membranes surrounding the frit, the water flowing across the surface of the membranes (instead of passing through the membrane) helps to mitigate the issue of clogging over time. However, questions remain as to the amount of energy that would be required to power a system like this when scaled up for real world applications.

The MIT team credits Juan Santiago at Stanford University for first discovering the use of a shockwave to separate salt concentration in water, but Santiago’s discovery wasn’t used for desalination applications until now. Bazant believes that shock electrodialysis could be easily scaled for massive desalination plants or water purification systems. Beyond desalination, the system could also be used to purify the toxic wastewater created by controversial fracking plants, since the electrical current could theoretically be used to sterilize the fluid stream in addition to removing unwanted particles in the water source.

Research into shock electrodialysis so far has proved the theory of the technique and has demonstrated working process models. The next step in bringing shock electrodialsysis to real world desalination and water purification applications will require the design of a system developed specifically for practical testing on that scale. Bazant and his team don’t believe their system will compete with traditional desalination processes at the outset, but he does see the benefit of the alternative treatment system down the line. For example, the minimal infrastructure requirements of the shock electrodialsysis system would make it a portable, inexpensive solution for emergency situations or remote locations where supplies are limited.

Emerging Tech

Awesome Tech You Can’t Buy Yet: A.I.-powered cat toys, wallets, food containers

Check out our roundup of the best new crowdfunding projects and product announcements that hit the web this week. You may not be able to buy this stuff yet, but it sure is fun to gawk!
Emerging Tech

These solar-powered water purifiers can produce 30,000 gallons of water per day

Problems with contaminated water? Quench Water & Solar's water purifiers can purify up to 30,000 gallons of fresh water per day and it's offering the technology to whoever wants it.
Home Theater

Demystify home audio with our ultimate A/V receiver buying guide

Today's A/V receivers are packed with lots of advanced technology and just plain cool features. From understanding watt ratings to Wi-Fi, we explain how to buy one that will last you for years in our ultimate A/V receiver buying guide.

These are the best Xbox One games out right now

More than four years into its lifespan, Microsoft's latest console is finally coming into its own. From 'Cuphead' to 'Halo 5,' the best Xbox One games offer something for everyone.
Home Theater

How to buy speakers: A beginner’s guide to home audio

From the difference between bookshelf speakers and monitors to the proper way to audition, our ultimate speaker buying guide has all the information you need to create your own home audio nirvana.
Emerging Tech

Here are the best (and least likely to explode) hoverboards you can buy

With widespread reports of cheap, knock-off Chinese hoverboards exploding, these self-balancing scooters may be getting a rough reputation. They're not all bad, though. Ride in style with our picks for the best -- and safest -- hoverboards
Emerging Tech

From electron microscopes to X-rays, high-tech tools expose low-tech art forgery

At the Indianapolis Museum of Art, conservation scientist Greg Smith and Glennis Rayermann, then a Ph.D student, used high-tech equipment to determine if a painting was made by master forger Icilio Federico Joni.
Product Review

Parrot Anafi drone review

It’s definitely not perfect, and there are a few little things that could be improved, but even so, Anafi is unquestionably the best drone that Parrot has ever made.
Emerging Tech

Looking for a good read? Here are the best, most eye-opening books about tech

Sometimes it's sensible to put down the gadgets and pick up a good old-fashioned book -- to read about the latest gadgets, of course. Here are the tech books you need to check out.
Emerging Tech

SpaceX Starlink: Here’s everything you need to know

SpaceX Starlink is the name of Elon Musk's ambitious plan to blanket the globe with high speed broadband internet via a network of satellites. Here's everything you need to know about it
Emerging Tech

Flying food: Uber has set a target date to use drones for meal delivery

Uber is better known for transporting people around town, but it also has a growing meal-delivery business called UberEats. It currently uses drivers and cyclists to deliver the food, but also has plans to use drones.

NYPD pulls thousands of body cams after one explodes

The NYPD has recalled thousands of body cameras after one of them exploded during an officer's shift on Sunday, October 21. No one was injured in the incident, which is thought to have been caused by the device's battery.
Emerging Tech

There’s finally a way to trace ‘untraceable’ 3D printed guns

To help track 3D-printed guns, researchers have developed a new algorithm which is able to identify which 3D printer was used to print an object, based on its unique fingerprint. Here's how.
Smart Home

Silo A.I. vacuum storage system tells you when your leftovers are going bad

"Alexa, is the chicken still OK to eat?" Newly launched on Kickstarter, Silo is a neat vacuum storage container that will extend your food's shelf life -- and add in a useful dose of A.I., too.