Future Now
The IFTF Blog
Nanotubes for clean water
"According to the World Health Organization, 1.1 billion people around the world lack access to safe water. Dirty drinking water is to blame for approximately 240 child deaths every hour, almost all of them occurring in developing nations. During our Mapping The Long Term Future presentation at the Technology Horizons Spring Exchange last month, my colleague Mike Liebhold mentioned that one application of carbon nanotubes could be as membrane material in inexpensive and efficient filtration systems. An article in Technology Review magazine this week reports on progress in this area.
Researchers at Lawrence Livermore National Laboratory have prototyped a carbon nanotube-based membrane they expect could cut the cost of purifying sea water by 75 percent. Tge researchers estimate that the technology could be ready for market within ten years. From the Technology Review article:
The membranes, which sort molecules by size and with electrostatic forces, could also separate various gases, perhaps leading to economical ways to capture carbon dioxide emitted from power plants, to prevent it from entering the atmosphere.
The carbon nanotubes used by the researchers are sheets of carbon atoms rolled so tightly that only seven water molecules can fit across their diameter. Their small size makes them good candidates for separating molecules. And, despite their diminutive dimensions, these nanopores allow water to flow at the same rate as pores considerably larger, reducing the amount of pressure needed to force water through, and potentially saving energy and costs compared to reverse osmosis using conventional membranes.