Researchers in Australia use filter to make seawater drinkable in half an hour

SYDNEY－Using only a high-tech filter and the power of direct sunlight, Australian researchers have developed a world-first technology that can make large volumes of seawater safe to drink in under 30 minutes.

According to the Melbourne-based Monash University, the specially-designed filter is capable of generating hundreds of liters of drinkable water per day, and requires only direct sunlight to purify it, making the process energy-efficient, low cost and sustainable.

Used in making the filters are metal-organic frameworks, or MOF, a class of compounds consisting of metal ions that form a crystalline material with the largest surface area of any material known.

During the desalination process, a functionalized MOF filter firstly adsorbs salts from water, which consumes no energy, then the salt-filled MOF can be put under sunlight to regenerate, taking fewer than four minutes, before it can absorb salt from water once more.

Lead author of the research paper, professor Huanting Wang from the Department of Chemical Engineering at Monash University, says the desalination is a feasible option to address the pressing water shortage crisis around the world.

"Desalination has been used to address escalating water shortages globally. Due to the availability of brackish water and seawater, and because desalination processes are reliable, treated water is able to be integrated within existing aquatic systems with minimal health risks," Wang says.

"But thermal desalination processes by evaporation are energy-intensive, and other technologies, such as reverse osmosis, has a number of drawbacks, including high energy consumption and chemical usage in membrane cleaning and dechlorination."

With low energy consumption and no chemicals needed during the process, Wang says this highlights the durability and sustainability of the new technology for future clean water solutions.

"This study has successfully demonstrated that the photo-responsive metal-organic frameworks are a promising, energy-efficient and sustainable adsorbent for desalination," he says.

"Our work provides an exciting new route for the design of functional materials for using solar energy to reduce the energy demand and improve the sustainability of water desalination."

Xinhua