Nanotech desalination membrane developed

LOS ANGELES, Nov. 7 (UPI) -- U.S. researchers say they've developed a reverse osmosis membrane that promises to cut the cost of seawater desalination and wastewater reclamation.

Reverse osmosis desalination uses extreme high pressure to force saline or polluted waters through the pores of a semi-permeable membrane. Water molecules under pressure pass through the pores but salt ions and other impurities cannot, resulting in highly purified water.

Civil and environmental engineering Assistant Professor Eric Hoek and colleagues developed the membrane at UCLA's School of Engineering and Applied Science. It uses a uniquely cross-linked matrix of polymers and engineered nanoparticles designed to draw in water ions but repel nearly all contaminants.

"The nanoparticles are designed to attract water and are highly porous, soaking up water like a sponge, while repelling dissolved salts and other impurities," Hoek said. "The water-loving nanoparticles embedded in our membrane also repel organics and bacteria, which tend to clog up conventional membranes over time."

The improvements result in a water purification process that is as effective as current methods but more energy efficient and potentially much less expensive, Hoek said.