UNSW’s Global Water Institute revolutionises desalination

The UNSW Global Water Institute (GWI) is developing a solar-powered desalination technology called Capacitive Deionisation (CDI) in hopes of revolutionising irrigation and food production.

The new technology should provide dependable water supplies to the agricultural industry that are cost effective, and work in isolation from the grid.

The idea was born when Ratan Tata, chairman of the philanthropic Tata Trusts in India, visited UNSW.

Professor David Waite, from the School of Civil and Environmental Engineering, began work on a second and third generator unit inspired by Tata’s visit.

Once constructed, the solar powered generator units had reduced energy usage by recovering a portion of the energy used.

“Scope exists for use of this technology in remote parts of Western Australia and the Northern Territory where the treatment of brackish water, typically the only water available, has been problematic using existing technology,” said Waite.

“For this project, we innovated in both the mode of operation of the established technology of membrane capacitive deionisation (MCDI) and the use of solar energy combined with energy recovery to power the device,” he said.

The technology works by passing water through a stack of electrode pairs with positive ions, removing salt from the brackish water.

A desalted stream of water is produced when a voltage is employed across the electrodes.

Although conventional CDI’s use main power, UNSW researchers are prototyping CDI powered by solar energy.

Using solar energy CDI allows the technology to be used in remote-off grid communities due to its energy efficiency and easy maintenance, UNSW explains.

As Australia’s most advanced water research centre, researchers at the institute hope that such technology will improve the agriculture industry and provide a reliable source of water by revolutionising irrigation through desalination.