A process that has been present on the planet for billions of years in the form of rain and that it seems that finally some scientists have managed to make it efficient and sustainable to be able to convert salty water into drinking water using solar energy.
A team from MIT (Massachusetts Institute of Technology) in the United States has presented a portable desalination system to be used wherever it is needed. This team launched this system in a competition led by USAID to promote better solutions to periods of water scarcity in certain periods in developing countries.
To get the first prize of $ 140.000, participants had to demonstrate not only that their invention worked, but that it was economical, environmentally sustainable and energy efficient.
The proposal of this team is based on using solar panels to charge a group of batteries that supply energy to an electrodialysis machine that removes salt from water and makes it drinkable and ready for consumption.
David L. Chander explains how it works: «Electrodialysis works by passing a stream of water between two electrodes with opposite charges. Due to the dissolved salt in the water containing positive and negative ions, the electrodes "push" the ions out of the water leaving the drinking water in the center of the stream. A series of membranes separates what is the stream of water without salt from that which does contain it.«.
One of the greatest virtues of this system is the use of membranes that because they are under an electrodialysis system do not support a lot of load and pressures which allows them to last much longer and require less maintenance. These membranes must be counted on to have a high cost.
Chandler reports that this system can convert 90 percent of salt water into ready-to-drink water, which is in itself a very high percentage compared to other systems such as reverse osmosis.