Electrode desalination without an applied current
A group of European researchers have evolved a desalination technology by creating an ion adsorption/desorption cycle without using an applied cell voltage.In a paper for the American Chemical Society's Journal of Physical Chemistry Letters (2012, 3 (12)), the researchers, who work at the Wetsus centre and Wageningen University in the Netherlands, describe their development as Water Desalination With Wires.
Their novel capacitive technology involves anode/cathode wire pairs constructed from electrically conducting rods coated with a thin porous electrode layer of carbon. By alternately dipping an array of electrode pairs in fresh water and brine without an applied voltage, an ion adsorption/desorption cycle can be created.
They have shown experimentally how, in six subsequent cycles, the salinity of a brackish feedwater (20 mM - millimolars) can be reduced by a factor of 3. Potable water has a salinity of <15 mM.
Though unsuitable for seawater desalination, the researchers believe their method could compete with other technologies in certain brackish situations because of its low cost.
© Faversham House Group Ltd 2012. Water. desalination + reuse news articles may be copied or forwarded for individual use only. No other reproduction or distribution is permitted without prior written consent.