Korean scientists have developed a new technology that enhances seawater desalination performance four times higher than the conventional method.
The new technology is dubbed “carbon-nanotube-based high-efficiency capacitive water desalination technology.” It was developed by a joint research team led by Dr. Kim Dong-guk of the Korea Institute of Energy Research (KERI) and Dr. Yoo Choong-yeol of Department of Energy System Engineering at Soon Chun Hyang University.
KERI said on Jan. 16 that the technology was published in Water Research, one of the top journals in the field of water resources.
Capacitive seawater desalination is a technology to refine salt from seawater using a capacitive deionization method. This technology has attracted more attention than conventional filter or distillation-based technologies due to its high energy efficiency.
While flow-electrode based seawater desalination technology is more energy efficient, it is not without its own problems. Unlike the conventional seawater desalination technology that uses fixed electrodes, it uses flowing electrodes, which lower the conductivity of the electrode. Due to the low conductivity, the amount of salt ions adsorbed by the electrode material is reduced, thereby deteriorating desalination performance.
To overcome such a problem, the researchers developed a way to improve the conductivity of the flow electrodes by adding carbon nanotubes with high conductivity to the activated carbon slurry electrode after chemical treatment. The 1 millimeter (mm)-long carbon nanotube added to the electrode acts as a conductive bridge that electrically connects the activated carbon particles in the fluid. As a result, more salt ions were absorbed by the activated carbon particles, enhancing the deionization performance more than four times than that of the conventional technology.