Excerpts taken from SOURCE article: Scientists reveal key insights into emerging water purification technology, August 6, 2019, by Anne Manning
“With water scarcity a critical challenge across the globe, scientists and engineers are pursuing new ways to harvest purified water from unconventional sources, like seawater or even wastewater. One of those researchers is Tiezheng Tong, an assistant professor in the Department of Civil and Environmental Engineering, whose lab is studying an emerging technology called membrane distillation.
Membrane distillation involves a thin, water-repellant membrane that exploits vapor pressure differences between hotter impure liquid, called “feedwater,” and colder purified water, called “permeate.” During the process, water vapor passes through the membrane and is separated from the salty or dirty feedwater. According to Tong, membrane distillation works better than other technologies like reverse osmosis, which can’t treat extremely salty water such as desalination brines or produced water from hydraulic fracturing. While it holds promise, membrane distillation doesn’t work perfectly. A key challenge is designing membranes to purify water efficiently while ensuring zero contamination of the clean water.
Tong and materials scientist Arun Kota in the Department of Mechanical Engineering joined forces to get at the fundamental science behind designing that perfect membrane. In new experiments they describe in Nature Communications, the CSU engineers offer new information into why certain membrane designs used in membrane distillation work better than others.
“The fundamental knowledge from our paper improves mechanistic understanding on the water-vapor transport within microporous substrates and has the potential to guide the future design of membranes used in membrane distillation,” Tong said.”