Researchers at MIT have created a portable desalination system that can produce safe drinking water from seawater. The unit is the size of a suitcase and weighs around 20 lbs. Unlike other portable desalination units, it does not require any filters or high-pressure pumps. It requires less power than a cell-phone charger to operate and can even run on solar, making it ideal for remote locations.
The work is a 10-year culmination of research and development by Jongyoon Han and his group. Han is a professor of electrical engineering and computer science and of biological engineering, and a member of the Research Laboratory of Electronics (RLE).
Rather than using filters, the unit relies on a technique called ion concentration polarization (ICP). Han’s group pioneered the technique more than 10 years ago. The ICP process applies an electrical field to membranes placed above and below a channel of water. The membranes repel positively or negatively charged particles — including salt molecules, bacteria, and viruses — as they flow past. The charged particles are funneled into a second stream of water that is eventually discharged.
The process removes both dissolved and suspended solids, allowing clean water to pass through the channel. ICP does not always remove all the salts floating in the middle of the channel. An electrodialysis process is used to remove remaining salt ions.
The researchers hope to make the device more user-friendly and improve its energy efficiency and production rate through a startup to commercialize the technology.