Australian and Chinese researchers have made a breakthrough in desalination technology that they say could benefit billions of people worldwide.
In a new study, which was published by the University of South Australia (UniSA), researchers found that common clay minerals can make seawater evaporate faster than freshwater.
UniSA researchers had previously demonstrated the potential of interfacial solar-powered evaporation as an energy-efficient and sustainable solution to alleviate global freshwater scarcity.
However, the method was constrained by the lower evaporation rate for saltwater than freshwater due to the negative effects of salt ions on evaporation.
In the new study, UniSA materials science researcher Xu Haolan and collaborators from Australia and China reversed the limitation by introducing inexpensive and common clay minerals into a floating hydrogel evaporator.
The team achieved seawater evaporation rates that were 18.8 percentage points higher than pure water. Previous studies found that seawater evaporation rates were around 8 percentage points lower than pure water.
“This new strategy, which could be easily integrated into existing evaporation-based desalination systems, will provide additional access to massive amounts of clean water, benefitting billions of people worldwide,” Xu said. He said that the key to the breakthrough lies in the exchange of ions at the air-water interface.
The researchers found that the evaporator maintained its performance even after months of immersion in seawater. The team will next explore further strategies to accelerate seawater evaporation.
