Researchers at the Politecnico di Torino, in collaboration with the Massachusetts Institute of Technology (MIT), have created a solar desalination device which helps remove accumulated salt during water desalination.

The biggest drawback of the current water desalination technologies is that during the process, the crystallized salt gets stuck within the machines. This causes clogging which leads to a deprovement in the overall performance of these machines overtime. If we tackle this problem, the production of freshwater will be much more durable for the same machines.

Although methods to prevent this were found like using nanostructured material which have anti-clogging properties, these methods are way too costly for mass-production and replacing the machinery might be more cost effective.

To find another way out for this issue, a team of engineers went all down to the mechanisms underlying the transport of salt particles. An interesting thing found was the huge difference between the theoretical models and the experimental observations of salt transport.  A further study regarding this was done and it is shown that the differences due to the Marangoni effect.

The Marangoni effect, in simple words, is the tendency of liquid molecules (at different concentrations in an aqueous solution) to generate cohesive forces between each other through intermolecular bonds.

In their desalination device (where the treated solutions are based on sea water at different concentrations), this phenomenon allows to avoid the accumulation of salt in the evaporators, ensuring constant and lasting productivity of distilled water, and safeguarding the components subject to deterioration. Therefore they designed a device capable of taking full advantage of this effect, achieving a further step towards future commercial applications of the device.

In the current version and considering an area for the absorption of solar energy of about one square meter, the desalination device can supply more than 15 liters of water per day. Furthermore, thanks to the Marangoni effect, the salt removal process is up to 100 times faster than predictions based on spontaneous diffusion, thus favoring a rapid restoration of the properties of the components.