The polymer, studied by American and Australian scientists, would also allow extracting lithium from the oceans in a simple and sustainable way. 🏖️
According to the WHO, 848 million people in the world do not have access to safe drinking water, and it is estimated that in seven years half of humanity will suffer shortages of this vital resource. A joint work carried out by scientists from the University of Texas at Austin (USA), Monash University and the Commonwealth Scientific and Industrial Research Organization (CSIRO), these last two institutions in Australia, proposes a new method to alleviate the problem: use as a filter a material that could purify seawater in the most sustainable, efficient and cheapest way possible.
The idea is to take advantage of the qualities of so-called metal-organic structures (MOF), a type of compounds whose internal surface area is the largest among all known substances. And what is even more interesting: it emulates a capacity of cell membranes technically called "ionic selectivity", as the researchers have discovered. According to his observations, the group of MOF polymers would have the potential to carry out with great efficiency a double function: remove salts from water and separate their metal ions. The research has been published in the journal ScienceAdvances.
Cheapest desalinators 💸
In the first place, the use of MOF would represent a significant advance in the desalination processes, which use similar membranes - called reverse osmosis - with a still very high energy expenditure. 70% of the 18,000 desalination plants that currently exist on the planet resort to this technique, and experts believe that its energy efficiency has the potential to double or triple through the application of technological improvements.
Today, only between 1% and 3% of drinking water comes from this source. By getting closer to the biological processes carried out by the cells, the polymers studied by the Australian experts would reduce costs considerably.
Secondly, and not least, the MOFs promise to revolutionize the lithium mining sector, an essential and increasingly coveted ingredient in the manufacture of batteries for devices or electric cars. This has been explained by Professor Huanting Wang, from the University of Monash, one of the authors of the study: "Lithium ions abound in seawater, so our work has implications for the mining industry, which currently uses treatments inefficient chemicals to extract lithium from rocks and brines ". The ionic selectivity of the MOFs would allow obtaining the valuable mineral from a practically inexhaustible resource: the oceans.