The most basic way of purifying water is to boil it. This holds true for sea water as well.
Even though it sounds easy on paper, it takes a lot of time and energy to complete.
A team of researchers from Rice University have come up with a new method of purifying water that not only decreases the amount of energy required for the process, it works without electricity as well.
The study was carried out at the Center for Nanotechnology Enabled Water Treatment (NEWT) at Rice University. Since its inception in 2015, NEWT has been working on “nanophotonics-enabled solar membrane distillation” or NESMD.
How it Works
Hot and cold water is separated by a thin membrane, water vapor is drawn from hot water to cold water which separates the salt(s). This saves energy as the water only needs to be heated and not boiled (boiling/melting uses a lot of energy).
The team also incorporated another step into the process to improve the efficiency of the system. They combined commercially available membranes with nano particles that convert light into heat. This means that you won’t need to manually heat the water as sunlight will do that for you.
The entire system can run on just a couple of solar panels, thanks to low energy requirements.
During their research the team also discovered that concentrating solar power increases the efficiency further. One of the researchers, Qilin Lin says,
The intensity got up 17.5 kilowatts per meter squared when a lens was used to concentrate sunlight by 25 times, and the water production increased to about 6 liters per meter squared per hour.
Another important features is that this system is completely modular. It can be easily taken apart, transported to remote areas then reassembled there. The researcher added that,
Direct solar desalination could be a game changer for some of the estimated 1 billion people who lack access to clean drinking water. This off-grid technology is capable of providing sufficient clean water for family use in a compact footprint, and it can be scaled up to provide water for larger communities.