One of the great opportunities in desalination research is developing a new way to bring drinkable water to disadvantaged people with limited resources. Engineers and researchers make this possible in many ways, such as innovating less expensive parts or powering their systems with renewable energy.
A team from MIT has done both of these and made their desalination system no bigger than a suitcase.
Electricity replacing filters and pumps
Jongyoon Han, a professor of electrical engineering, computer science, and biological engineering, and his team developed a device that weighs less than 10 kilograms (22 pounds) and requires less energy to function than a cell phone. Not only that, but it can also run on solar power from a portable, collapsible panel that one can buy online for $50. Han and his team designed it to be user-friendly, as simple as opening it up and pushing a button.
Unlike other portable desalination units that use high-pressure pumps pushing water through filters, this new system uses ion concentration polarization (ICP), a process that Han and his team developed 10 years ago. This ICP system uses only a low-pressure pump and applies electrical fields above and below the flow of water which repel positively or negatively charged particles like salt, bacteria, and viruses. Then the charged particles are funneled into a second stream and separated from the drinking water.
The ICP process does not catch all the salt, though, so the team added an electrolysis stage which removes the remaining salt ions.
A day at the beach
Han and his team took the device to Boston’s Carson Beach to test it on water with high salinity and murkiness. Half an hour after putting a tube in the water and running the system, the team had a plastic cup full of purified drinking water.
When they tested it, they found that the filtered water actually exceeded the World Health Organization quality standards.
“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,” said Han.
This system is not only energy-efficient, its size and user-friendliness make it accessible to a whole variety of communities around the world that might not have plentiful resources or training in advanced equipment. Not only that, the device could be used in any number of emergencies on seacraft or with rescue teams. Han and the team next want to bring the device into the testing stages and then commercialize the technology.