For the first time, researchers have designed an electrochemical cell that can desalinate seawater (Nano Lett., DOI: 10.1021/nl203889e). They think that its cost and efficiency eventually could improve on standard techniques of purifying seawater.
Worldwide demand for freshwater is skyrocketing as the population increases. Many of today’s desalination plants use reverse osmosis or evaporation, both of which require enormous amounts of energy to supply heaters or high-pressure pumps. To find cheaper, room-temperature, energy-efficient solutions, many researchers are looking to nanomaterials and electrochemistry.
The new system uses both. It first draws ions from seawater into a pair of electrodes. As the researchers pass current through the electrodes, electrochemical reactions drive chloride ions into a silver electrode and sodium ions to an electrode made from manganese oxide nanorods. Next, the researchers remove the desalinated water and release the trapped ions into a separate stream of waste seawater by reversing the direction of the electrical current. Although the pilot experiments were not automated, the researchers say that a pump could automate the process — via redwolf.newsvine.com