found this fascinating...

http://phys.org/news/2012-06-nanopor...alination.html

(Phys.org) -- Although oceans and seas contain about 97% of Earth’s water, currently only a fraction of a percent of the world’s potable water supply comes from desalinated salt water. In order to increase our use of salt water, desalination techniques must become more energy-efficient and less expensive to be sustainable. In a new study, two materials scientists from MIT have shown in simulations that nanoporous graphene can filter salt from water at a rate that is 2-3 orders of magnitude faster than today’s best commercial desalination technology, reverse osmosis (RO). The researchers predict that graphene’s superior water permeability could lead to desalination techniques that require less energy and use smaller modules than RO technology, at a cost that will depend on future improvements in graphene fabrication methods.

The scientists, David Cohen-Tanugi and Jeffrey C. Grossman of MIT, have published their study on water desalination using single-layer nanoporous graphene in a recent issue of Nano Letters.
“This work shows that some of the drawbacks of current desalination techniques could be avoided by inventing more efficient and targeted membrane materials,” Grossman told Phys.org. “In particular, tailored nanostructuring of membranes could allow for actual flow of water (with full salt rejection) via size exclusion, leading to much higher permeability compared to reverse osmosis.”

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