Slashdot Mirror
New Process For Nanoscale Filtration Holds Promise of Cheap, Clean Water
New submitter Spinnakker writes "Lockheed Martin, traditionally known for its development of military systems and aircraft, has developed a process for perforating graphene (carbon sheets only one atom thick) that could potentially reduce the energy required for desalination by two orders of magnitude. The process tailors the hole size to the molecules being separated. In the case of desalination, one would create holes in the graphene large enough to allow water to pass but small enough to block the salt molecules. The advantage to using graphene comes from how extremely thin the material is compared to traditional filters. The thinner the filter, the less energy is required to facilitate reverse osmosis."
Considering that the theoretical minimal energy requirement for seawater desalination is approx. 0.75 kWh/m3 and current RO technology can be as low as 1.5 to 2 kWh/m3 (+ an other 2 kWh/m3 to pretreat the seawater) then I am really wondering how they will gain two orders of magnitude less energy? Can anybody enlighten us about that?
The issue with normal filtration is you need to replace the filter media after so many gallons. The issue with normal desalination is you need a lot of energy to purify the water.
Yes you need to re-add minerals when you use this new filter for watering plants and properly hydrating the human body, but think about it. With this invention you get a filter that will pretty much last forever with no degradation as long as it is maintained properly, and you can get fresh water from the sea and toxic sources without having to use up a ton of energy and money. In the end this idea is win-win, just make sure to include the trace minerals before drinking.