"Water, water, everywhere,
Nor any drop to drink."
– Samuel Coldridge, The Rime of the Ancient Mariner, 1798
There may be plenty of water on our blue planet, but the vast majority (almost 98%) is unfit for human use. Today, an estimated three hundred million people now meet their water needs with water that is too salty to drink. And the situation isn't getting any better. Climate change and population growth are causing precious freshwater resources to evaporate before our very eyes.
Enter desalination. The process of removing salt from sea or brackish groundwater took off in the oil-rich Middle East in the 1970s and has since spread to 150 countries. The problem? Besides the harmful concentrated brine left behind by the process, desalination is hugely expensive and energy-intensive.
But new technologies are helping the cause.
National Geographic reports on three new technologies that promise to reduce the energy (and cost) requirements of removing salt from water, while warning that none are simple and cheap enough to offer much hope to the world’s poor,
(Via National Geographic)
Information graphic by Bryan Christie