To achieve more effective saltwater desalination, mechanical engineers focused on fluid movement rather than new materials in a new study. By adding microchannels to the inside of battery-like electrodes made of Prussian blue – an intense blue pigment often used in art that also has special chemical properties – researchers increased the extent of seawater desalination five times over their non-channeled counterparts to reach salinity levels below the freshwater threshold.

The study, led by University of Illinois Urbana-Champaign mechanical engineering and science professor Kyle Smith and graduate student Vu Do, used a chemical analog to Prussian blue. The findings are poised for applications in desalination, energy conversion and storage, CO2 conversion and capture, environmental remediation, and resource and nutrient recovery.

The study is published in the journal Energy and Environmental Science.

“In previous work, we predicted desalination could be performed using this method, but nobody had validated seawater-level desalination in the lab,” Smith said. “In the interim, we learned that in addition to the specific kind of material used in the electrodes, the system’s configuration also matters.”

Read more at University of Illinois Grainger College of Engineering

Image: A chemical analog to Prussian blue, the intense blue pigment used in Hokusai’s woodblock print “The Great Wave off Kanagawa,” is being utilized in an updated saltwater desalination technique. Mechanical engineers at U. of I. are using it in a new electrode equipped with flow channels to make the desalination process more effective and efficient. (Credit: Katsushika Hokusai, public domain, via Wikimedia Commons)