"Electrochemically Mediated Seawater Desalination" Makes a Splash
By creating a small electrical field that removes salts from seawater, CEC chemists in the Crooks group at The University of Texas at Austin and the University of Marburg in Germany have introduced a new method for the desalination of seawater that consumes less energy and is dramatically simpler than conventional techniques.
The new method requires so little energy that it can run on a store-bought battery. Graduate student Kyle Knust in the Crooks research group is conducting research in electrochemical membraneless desalination. A 3.0 V potential bias is applied across a microelectrochemical cell comprising two microchannels spanned by a single bipolar electrode (BPE) to drive chloride oxidation and water electrolysis at the BPE poles. The resulting ion depletion zone and associated electric field gradient direct ions into a branching microchannel, producing desalted water.
The process evades the problems confronting current desalination methods by eliminating the need for a membrane and by separating salt from water at a microscale. The technique, called electrochemically mediated seawater desalination, was described in a recent publication in Angewandte Chemie. The research team was led by Richard Crooks of The University of Texas at Austin and Ulrich Tallarek of the University of Marburg. It’s patent-pending and is in commercial development by startup company Okeanos Technologies.
“The availability of water for drinking and crop irrigation is one of the most basic requirements for maintaining and improving human health,” said Crooks, the Robert A. Welch Chair in Chemistry in the College of Natural Sciences. “Seawater desalination is one way to address this need, but most current methods for desalinating water rely on expensive and easily contaminated membranes. The membrane-free method we’ve developed still needs to be refined and scaled up, but if we can succeed at that, then one day it might be possible to provide fresh water on a massive scale using a simple, even portable, system.”