Scientists have used solar energy to turn salty water into fresh water

Scientists have found a way to get fresh water from salt, using only solar energy. This can be a serious breakthrough in methods of desalination.

Modern desalination plants

At present, expensive and energy-intensive desalination plants are used to remove salt from water. In essence, to desalinate the water, it should be boiled, and then capture and condense the steam. To boil water requires a large amount of heat, resulting in half the cost of the installation is determined by the need for energy.

How the sun's energy is used

However, a new study, the results of which were published in the Proceedings of the National Academy of Sciences, can change the rules of this game. It was conducted by scientists of the Center for Water Treatment using Nanotechnology (NEWT) at Rice University in Texas.

"Direct desalination with solar energy can ease the lives of about 1 billion people who do not have access to clean water," said research co-author and water treatment expert Kilin Lee. "The new off-grid technology will provide many families with clean water."

Membrane distillation

The technology in question includes so-called membrane distillation. Desalination is due to the fact that heated salt water flows along one side of the membrane, and cold fresh water flows along the other side of the membrane. This allows you to remove water vapor from hot to cold side. Nevertheless, although energy costs in this case are reduced, the constant use of heat indicates that they are still significant.

However, NEWT technology is more efficient. It uses developed nanoparticles that can convert sunlight to heat. If you add them to the membrane, it will heat up by itself, so to heat the water does not require a lot of energy. This technology is called NESMD.

Desalination speed

To prove the effectiveness of using the new technology, a team of scientists used the NESMD camera, whose sizes were equal to three postage stamps, and the thickness - to several millimeters. The desalination rate of water, which scientists received, was about 6 liters per square meter. M of their installation per hour. Their idea is that in the future people will be able to order NESMD panels, the number of which will depend on their daily water needs.

"Depending on the desalination rate you need, you could calculate what area of the membrane you will need," Lee said. "For example, if you need 20 liters per hour and the panels produce 6 liters per hour per square meter, You will need to order a little more than 3 square meters of panels. "