Obtaining water suitable for seawater consumption only with solar energy would provide an answer to the a billion people who live in the world without access to this resource and, in many cases, without connection to the power grid. This possibility is more likely today, after a science team from Rice University found a revolutionary design for water desalination only thanks to the energy captured by the sun.
“Direct solar desalination can be a game-changer for the billion people without access to drinking water ”, says water treatment expert Qilin Li, promoter of this “A technology outside the network capable of providing enough clean water to supply a family and that it can be expanded to provide water to larger communities “, develops the idea promoted by the Center for Nanotechnology to Purify Water (NEWT), for its acronym in English.
Compared to the classic method of obtaining fresh water from salt water, which is none other than distillation, this idea starts from membrane distillation to improve its efficiency, because this method is still very expensive in energy. . To overcome these pitfalls, this scientific team worked on a nanoparticle membrane that uses up to 80% of sunlight to generate steam.
Incorporating inexpensive nanoparticles into a porous membrane not only reduces the investment required to produce the system, but turns the membrane into a heating element which on its own heats the water for distillation. “The integration of photothermal heating properties in a membrane for direct and solar distillation opens up new opportunities in water purification “says Menachem Elimelech, co-author of the study.
This initiative has already been subjected to various tests at Rice University. First, tests were carried out in a small chamber (the equivalent of three postage stamps). The results showed that the behavior of the system improves considerably with the concentration of solar energy. “Intensity increased to 17.5 kilowatts per square meter using lenses to concentrate solar energy”, explains Li, who adds that water production has thus increased for six liters per square meter per hour.
Scientists are currently working on building a much larger system that incorporates a 70 x 20 centimeter panel. the the ultimate goal is to produce a modular system that allows users to use the panels they need depending on the desired amount of water. “You can assemble them as you would with the panels of a solar installation”, the scientist says of the next step in this breakthrough that may address a rooted problem for millions of people around the world.
More information in Rice University.