New Desalinating System Uses Shockwaves For Turning Saltwater Into Drinking Water

 MIT Researchers Discover New Process for Converting Salt Water into Drinking Water: Desalination systemsMIT Researchers Discover New Process for Converting Salt Water into Drinking Water: Desalination systems

 

As populations continue to grow and the planet continues to heat up, the issue of clean drinking water has become a growing concern. While there have been advances in desalination technology, many of them are costly and are only capable of desalinating small amounts of sea water at a time. Now, researchers at MIT’s Department of Chemical Engineering have discovered a new way to remove salt from ocean and brackish water, including that generated from fracking.

Emergency Uses


The team at MIT has designed a new desalination system that uses, of all things, a shockwave to remove salt from seawater, something we have in abundance. The method could turn out to be both practical and energy efficient for the purpose of desalination in providing water purification to remote areas and for use in emergencies. This would be especially useful after hurricanes and tsunamis that wreak havoc, like the one in Japan back in 2011 or several years earlier in the Indian Ocean.

 

New Desalinating System Uses Shockwaves for Creating Drinking Water: Desalination System Illustration: MITtleman Lab/Brown UniversityNew Desalinating System Uses Shockwaves for Creating Drinking Water: Desalination System Illustration: MITtleman Lab/Brown University

 

Desalination Systems


MIT’s Professor Martin Bazant has been experimenting with a process called shock electrodialysis that uses very little energy and no thick membranes, like other desalination systems from the past. In this new design, water would flow through a charged porous material made of tiny glass particles sintered together. Sintering is the process of compacting and forming solid masses through heat and/or pressure without melting them to the point of liquefaction. It occurs naturally in mineral deposits and during manufacturing processes with metals, plastics, ceramics and other materials.

Turning Saltwater into Drinking Water


In MIT’s system, a small electric current is applied across the sintered glass material and the salt ions gather on one side of the flow, in turn creating an ion-rich side and an ion-deficient side. Once the current is increased sufficiently, the charged surface of the porous glass essentially generates a shockwave that divides the flowing water into two separate streams, one with desalinated drinking water and the other with salt. The two streams are separated at the center of the flow.

 

Desalinating Systems Turn Salt Water into Drinking Water: MIT prototype shows promiseDesalinating Systems Turn Salt Water into Drinking Water: MIT prototype shows promise

 

Environmental Science & Technology


Bazant, a professor of chemical engineering and mathematics, and the rest of the MIT scientists connected to the project, have already used the process in a prototype electrodialysis system. If you’re interested, the group published their findings on November 3 in the journal Environmental Science & Technology. This prototype was able to remove over 99 percent of salts while recovering up to 79 percent of the water used in the experiments. They also found it can remove various contaminants such as dirt and bacteria.

Using Shockwaves in Science


Because of the simplicity of the MIT desalination design, the team is eager to try scaling it up in size, especially since materials involved in the development of it are relatively inexpensive. They are currently working on a larger prototype for continuing their experiments. In a recent press release, the researchers noted that the system they’re working on “opens up a whole range of new possibilities for water desalination, both from seawater and brackish water resources, such as groundwater.” With advances like this, maybe we can get a handle on our water-shortage problems after all.