[font face=Serif][font size=5]Freshwater from salt water using only solar energy[/font]
Jade Boyd June 19, 2017
[font size=4]Modular, off-grid desalination technology could supply families, towns[/font]
[font size=3]HOUSTON (June 19, 2017) A federally funded research effort to revolutionize water treatment has yielded an off-grid technology that uses energy from sunlight alone to turn salt water into fresh drinking water. The desalination system, which uses a combination of membrane distillation technology and light-harvesting nanophotonics, is the first major innovation from the Center for Nanotechnology Enabled Water Treatment (
NEWT), a multi-institutional engineering research center based at Rice University.
NEWTs new technology builds upon research
in Halas lab to create engineered nanoparticles that harvest as much as 80 percent of sunlight to generate steam. By adding low-cost, commercially available nanoparticles to a porous membrane, NEWT has essentially turned the membrane itself into a one-sided heating element that alone heats the water to drive membrane distillation.
The integration of photothermal heating capabilities within a water purification membrane for direct, solar-driven desalination opens new opportunities in water purification, said Yale University s Menachem Meny Elimelech, a co-author of the new study and NEWTs lead researcher for membrane processes.
In the PNAS study, researchers offered proof-of-concept results based on tests with an NESMD chamber about the size of three postage stamps and just a few millimeters thick. The distillation membrane in the chamber contained a specially designed top layer of carbon black nanoparticles infused into a porous polymer. The light-capturing nanoparticles heated the entire surface of the membrane when exposed to sunlight. A thin half-millimeter-thick layer of salt water flowed atop the carbon-black layer, and a cool freshwater stream flowed below.
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