Monday, March 23, 2009

Drink Up: Taking the Salt Out of Seawater

FREE FROM SALT: Special membranes help desalinize 25 million gallons of water a day at the Tampa Bay Seawater Desalination Plant in Florida. COURTESY OF DOW

From Scientific American:

Removing the salt from briny water is becoming more affordable.

Almost three quarters of Earth's surface is covered with water, but most of it is too salty to drink. And the 2.5 percent that is freshwater is locked up either in soil, remote snowpacks and glaciers or in deep aquifers. That leaves less than 1 percent of all freshwater for humans and animals to drink and for farmers to use to raise crops—and that remnant is shrinking as rising global temperatures trigger more droughts. The upshot: it's becoming increasingly difficult to slake the world's thirst as the population grows and water supplies dwindle. Analysts at the investment bank Goldman Sachs estimate that worldwide water use doubles every 20 years.

Read more ....

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