People cannot survive without water, yet more than 10 percent of the world’s population lacks sufficient access to it — a figure likely to grow as climate change alters weather patterns and worsens droughts. While most of the planet is covered by water, 96 percent of it is too salty to drink.
Removing salt from seawater is possible, but not always practical. Conventional desalination plants that employ reverse-osmosis technology, used since the 1960s, are pricey: The new Carlsbad desalination plant in California, which outputs 50 million gallons a day, cost $1 billion to build.
The high price tag makes traditional desalination plants unfeasible for many communities. But now they have a simpler, cheaper alternative: the aero-desalinator, which harnesses the wind to wring freshwater from the brine.
How It Works:
The aero-desalinator, invented by engineer Juan Carlos Borrero, hooks up a windmill to a standard well. Wind power provides the pressure necessary to suck the well’s saltwater through a series of filters and membranes laced with copper and silver ions to kill off any potential pathogens, rather than the more expensive chemical compounds used in reverse-osmosis plants.
As unfiltered water passes through the membrane, the positively charged ions react with a microbe’s negatively charged cell walls, rendering it unable to reproduce or absorb nutrients.
From there, the still-salty water is sucked through reverse-osmosis membranes permeable to water molecules but not salt ions. The final result: purified freshwater.