Seawater needs to be treated before it can be fit for consumption. Distillation is a method that has long been used to treat seawater. It involves boiling the water into steam and then cooling the pure vapors in condensation tubes. However, this method requires a lot of energy as almost half of the input goes towards just boiling the water. Researchers at Rice University have come up with a more effective way of doing this by relying on sunlight.
A team of researchers from Rice University’s Center for Nanotechnology Enabled Water Treatment (NEWT) conducted this research. The center has developed the “nanophotonics-enabled solar membrane distillation” or NESMD technology in which the flows of hot and cold water are separated using a thin membrane.
This process is different than distillation as it draws water vapor across the membrane from the hot side to the code while straining the salt out of the water in the process. This needs much less energy than distillation since the water doesn’t need to be boiled, it only needs to be hot.
They have tried to push the efficiency of this system even further by using commercially available membranes that have nanoparticles which can convert light into heat. This eliminates the need to have a steady supply of hot water. All it then requires is sunlight.
“Direct solar desalination could be a game changer for some of the estimated 1 billion people who lack access to clean drinking water,” the researchers say.
They point out that this method is going to bring down the power requirements significantly, so much so that the entire system can be run off the grid with just a couple of solar panels.