Episode 151: Are there any problems with using water desalination to increase our water supply?
Meagan Mauter, a professor at Carnegie Mellon University, discusses the possibility of desalinating water to increase the water supply of areas experiencing drought conditions.
Saline Water: Desalination from the United States Geological Survey
Desalination of Ground Water: Earth Science Perspectives from the United States Geological Survey
Antifouling Ultrafiltration Membranes via Post-Fabrication Grafting of Biocidal Nanomaterials from the American Chemical Society
MODERATOR: Can we desalinate water to increase our water supply? On this week’s Energy Bite, Megan Mauter, a professor at Carnegie Mellon University, has some answers.
MEAGAN: We often hear about drought conditions in states like California and Texas that have ready access to salt water on their shores. In these areas, water desalination – the removal of salt from water—may be an important stopgap technology for providing freshwater when other resources and conservation measures have been exhausted.
In the most common way to desalinate water, reverse osmosis, salt water is passed through a semi-permeable membrane that retains salt, but allows water to pass through. This membrane is made from a very thin layer of polyamide polymer.
Unfortunately, the water desalination process is both expensive and consumes a lot of energy — on the order of 3-4 kWh per cubic meter, or the amount of electricity it takes to keep your iPhone powered for a full year.
MODERATOR: Can we do something about it?
MEAGAN: The lower the concentration of salt in your feed water, the less energy is needed to produce fresh water. So one way to reduce energy consumption of water desalination is to treat less saline water sources. Many reverse osmosis water treatment facilities use wastewater or low-salinity brackish water as the source water.
MODERATOR: Would you drink desalinated wastewater? Take our poll, see the results, and ask your energy questions at Energy Bite dot org.