MIT researchers have developed a portable desalination unit that is set to help millions have access to clean, drinking water. The unit created by the MIT team weighs less than 10 kg and removes particles and salts from sea water to make it safe for drinking. It also does not require a change of filters, considerably reducing costs.
Portable desalination units can be extremely useful in rural areas and disaster sites where access to clean water is limited or worse, non-existent. In coastal regions plagued by water problems, a sea water purification system can help restart the economy.
Filter-Free and Solar-Powered Technology
The desalination unit developed by the MIT research team only requires a small amount of electricity to perform its task. This feature also reduces additional maintenance requirements. It also does not require a change of filters, considerably reducing costs.
The suitcase-sized device requires less power than a cell phone charger and can also run on a small, solar-powered panel that is usually available online for approximately $50. The water desalination unit produces safe drinking water that exceeds the quality standards set by the World Health Organization. It is packed into a device that runs at the push of a button.
Senior author Jongyoon Han, a professor of electrical engineering and computer science and of biological engineering, and a member of the Research Laboratory of Electronics (RLE), said, “This is really the culmination of a 10-year journey that I and my group have been on. We worked for years on the physics behind individual desalination processes, but pushing all those advances into a box, building a system, and demonstrating it in the ocean, that was a really meaningful and rewarding experience for me.”
Energy Efficient and Portable
As the device uses electricity to remove unclean particles from water, it eliminates the use of filters. Junghyo Yoon, a research scientist in RLE mentions that commercially available desalination units usually require high-pressure pumps to push water through the filters. The unit created by them is easy to carry and energy efficient.
Through a technique called Ion Concentration Polarization (ICP), the process applies an electrical field to membranes placed above and below a channel of water. As the molecules repel positively and negatively charged particles, the charged particles pass through a second stream that is discharged. This process eliminates both suspended and dissolved solids, and pushes clean water through the channel. Once the salinity level and the number of particles decrease to specific thresholds, the device notifies the user that the water is drinkable. For easy access, the MIT research team also developed a smartphone app that will update the user on energy consumption and water salinity in real time. It can also be used to control the device wirelessly.
The current prototype generates drinking water at a rate of 0.3 liters per hour, and requires only 20 watt-hours per liter. Yoon revealed that they are currently working to increase the production rate. The team also wants to make the device more efficient and user-friendly so that it benefits more people. Yoon has plans to scale the production rate through a startup and eventually commercialize the technology.
He mentions that drinking water issues go beyond desalination, and includes the need for rapid detection of contaminants. As pleased as he is with the desalination, he also wants to optimize its value by figuring out a way to build it using low cost materials.
Above all, Yoon is well-aware that water scarcity is a rising problem across the world. As rising sea levels and droughts threaten access to drinking water, he wants to help people be prepared for the future. The MIT research team believes their device will be handy in severely resource-limited areas and while dealing with calamities.
