Water scarcity is one of the most critical issues facing the world today, with over two billion people struggling to access clean water.
As climate change and population growth intensify the demand for freshwater, scientists are exploring new solutions.
Desalination, the process of removing salt from seawater, is emerging as a promising way to meet this need.
However, current desalination methods produce large amounts of brine—a salty waste product that harms the environment and is costly to dispose of.
In fact, around 141.5 million cubic meters of brine are discharged from desalination plants every day.
To address this challenge, a research team led by Associate Professor Masatoshi Kondo from the Institute of Science Tokyo in Japan has developed a groundbreaking approach.
Their new method uses liquid metal tin to purify water and recover valuable metals from desalination brine.
The findings were recently published in Water Reuse.
The team’s innovative technology works by spraying brine onto the surface of liquid tin heated to 300°C.
When the brine touches the hot metal, freshwater instantly evaporates and is collected as distilled water. Meanwhile, important minerals such as sodium, magnesium, calcium, and potassium are left behind in the tin. This not only purifies water but also turns waste into a resource.
Dr. Kondo explains that this process can be powered by concentrated solar energy, making it both energy-efficient and sustainable.
Unlike traditional desalination methods, which require large amounts of electricity, this new technology relies mostly on heat. This makes it cheaper and more eco-friendly, opening up possibilities for large-scale desalination without the environmental downsides.
The researchers also developed a method for separating the metals after they are absorbed by the liquid tin.
As the tin cools slowly, different metals solidify at different temperatures. Potassium is recovered first, followed by sodium, calcium, and finally magnesium. This step-by-step process allows for targeted recovery of each mineral, adding economic value to what was previously just waste.
One of the most exciting aspects of this technology is its versatility. Dr. Kondo notes that it can also purify groundwater contaminated with arsenic—a major problem in countries like Bangladesh, India, and Vietnam. This means the same method could be used to solve multiple water challenges across the globe.
This innovative use of liquid metal tin could transform desalination and groundwater treatment, turning environmental problems into valuable opportunities.
With its sustainable energy requirements and minimal waste production, this method could help communities around the world access clean water while also recovering important minerals from seawater.
