As global warming worsens on our watch, there might eventually come a time when drinking water is harder to come by for a lot of the world. That’s why we need a better way to convert salt water to potable drinking water in case of emergencies. Inspired by the intricate system of water circulating in a tree, a team of researchers from Princeton University has figured out how to use a thin slice of wood as a membrane through which water vapor can evaporate.
Rather than using massive amounts of energy to boil water for long periods of time, the filtration method works by gently heating one side of the wood so that the water evaporates to the colder side of the wood, leaving behind salt or other contaminants. Most membranes that are used to distill fresh water from saltwater are made of polymers, which are derived from fossil fuels and are also difficult to recycle.
The wood membrane is a more sustainable material, and according to the researchers, performs 20% better than commercial membranes in water distillation tests. Collectively, the wood membrane method filtered 20 liters of water per square meter, but the team believes that they will be able to improve the system with additional experimentation.