Bottomless Well: De-Salting Water Could Help Drought-Stricken Areas
A team from the Massachusetts Institute of Technology and Jain Irrigation Systems has devised a method of turning brackish water into drinking water using renewable energy. This solar-powered machine is able to pull salt out of water and disinfect it with ultraviolet rays, making it suitable for both irrigation and drinking.
Electrodialysis works by passing a stream of water between two electrodes with opposite charges. Because the salt dissolved in water consists of positive and negative ions, the electrodes pull the ions out of the water, leaving fresher water at the center of the flow. A series of membranes separate the freshwater stream from increasingly salty ones.
The photovoltaic-powered electrodialysis reversal system recently won the top $140,000 Desal Prize from the U.S. Department of Interior. “This technology has the potential to bring agriculture to vast barren lands using brackish water,” says Richard Restuccia, Jain’s vice president of landscape solutions. The prize was developed to supply catalytic funding to capture and support innovative ideas and new technologies that could have a significant impact on resolving global water demand.
Among 13 desalination projects under consideration along the California coast, the Carlsbad Desalination Project will be the largest in the Western Hemisphere once it is completed in the fall.