Australian researchers have discovered a highly efficient and economically sustainable way to filter salt and metal ions from water.
With two billion people worldwide lacking access to clean and safe drinking water, joint research by Monash University, CSIRO and The University of Texas at Austin published in Sciences Advances may offer a breakthrough new solution.
It all comes down to metal-organic frameworks (MOFs), according to the paper – a next-generation material that has the largest internal surface area of any known substance.
The sponge like crystals can be used to capture, store and release chemical compounds. In this case, the salt and ions in seawater.
Dr Huacheng Zhang, Professor Huanting Wang and Associate Professor Zhe Liu and their team in the Faculty of Engineering at Monash University in Melbourne, Australia.
They worked in collaboration with Dr Anita Hill of CSIRO and Professor Benny Freeman of the McKetta Department of Chemical Engineering at The University of Texas at Austin, have recently discovered that MOF membranes can mimic the filtering function, or ‘ion selectivity’, of organic cell membranes.
With further development, these membranes have significant potential to separate metal ions in a efficient and cost effective manner, offering a revolutionary new technological approach for the water and mining industries.
In the mining industry, for example, membrane processes are being developed to reduce water pollution, as well as for recovering valuable metals.
In manufacturing, lithium-ion batteries are now the most popular power source for mobile electronic devices.
However, at current rates of consumption, there is rising demand likely to require lithium production from non-traditional sources, such as recovery from salt water and waste process streams.
“We can use our findings to address the challenges of water desalination,” Wang said. “Instead of relying on the current costly and energy intensive processes, this research opens up the potential for removing salt ions from water in a far more energy efficient and environmentally sustainable way.”
Building on the growing scientific understanding of MOFs, CSIRO’s Dr Hill said the research offers another potential real-world use for the next-generation material.
“The prospect of using MOFs for sustainable water filtration is incredibly exciting from a public good perspective, while delivering a better way of extracting lithium ions to meet global demand could create new industries for Australia,” she said.