Liquid metal discovery to make toxic water safe and drinkable

Researchers found that nano-filters made of aluminium oxide could be economically produced using virtually no energy from a fixed amount of liquid metal gallium and explained how when a chunk of aluminium is added to the core of liquid gallium at room temperature, layers of aluminium oxide are quickly produced at the surface of the gallium.

It was also discovered that these aluminium oxide nano-sheets were highly porous and its efficiency in filtering both heavy metal ions and oil contamination at unprecedented, ultra-fast rates.

 Researchers said these low cost and portable filters produced by this new liquid metal based manufacturing process could be used by people without access to clean drinking water to remove substances like lead and other toxic metals in a matter of minutes. This technology could be put to good use in Africa and Asia in places where heavy metal ions in the water are at levels well beyond safe human consumption. It is estimated that 790 million people, or one in 10 of the Earth's population, do not have access to clean water.

There are portable filtration products available that do remove heavy metals from water, but they are comparatively expensive, often costing more than $100. By contrast, aluminium oxide filters produced from liquid gallium could be produced for as little as 10 cents, making them attractive to prospective manufacturers. While aluminium is a plentiful and cheap metal, gallium is relatively expensive. But what makes gallium the hero in the process is the fact that it remains pure and unchanged after each production of aluminium oxide.