How can sea water be made drinkable?

Rescue for millions of people ?: A new type of filter makes seawater drinkable


2.2 billion people worldwide do not have regular access to clean water. Australian researchers have introduced a filter that aims to change that once and for all.

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  • Millions of people suffer from a lack of safe drinking water.
  • Australian researchers have now developed a filter that can desalinate more than 100 liters of seawater within 30 minutes with just the help of sunlight.
  • The method is not only productive, but also energy-efficient, inexpensive and sustainable.

No electricity, just sunlight - according to researchers at Monash University in Melbourne, nothing more is needed for the filter they have developed to turn inedible salt water into vital drinking water. As stated in the journal “Nature Sustainability”, this is the first technology with which large quantities of seawater can be made drinkable in just 30 minutes.

According to a statement from the university, the high-tech filter used by chemical engineer Huanting Wang and his colleagues can produce several hundred liters of drinking water per day, which meets the standards of the World Health Organization for desalination. All that is needed is direct sunlight - something that is abundant in regions where drinking water is particularly scarce.

Another advantage of the technology: It is energy-efficient, inexpensive and sustainable.

People or families in the poorer regions of the world are particularly affected by a lack of drinking water - and there in particular in rural areas, especially in Africa, Latin America and Asia. Because the drinking water supplies, which only make up 0.3 percent of the global water supply, are unevenly distributed.

The filter is based on so-called organometallic framework compounds, MOFs for short. These are microporous materials that consist of metal ions and, when they come into contact with salt water, remove the salts and bind them to themselves.

If the MOF, which is then filled with salt, which was specially created for the filter, is exposed to the sun, it releases all the salt ions that it previously attracted. Then it is ready for use again.

875 million people suffer

According to Wang and his colleagues, this represents a significant improvement over existing desalination methods. “Thermal desalination processes through evaporation are energy-intensive, and other technologies, such as reverse osmosis, have a number of disadvantages, such as high energy consumption and the use of chemicals in membrane cleaning and Dechlorination, ” quotes Wang.

Sunlight, on the other hand, is the most common and renewable energy source on earth. "Our development of a new desalination process based on adsorbents through the use of sunlight for regeneration offers an energy-efficient and environmentally friendly solution for desalination," explains the chemical engineer. However, it is still unclear whether and when the researchers will be able to bring their system into a functioning, practical form.

New solutions cannot come quickly enough - according to the WHO, around 785 million people do not even have a basic supply of drinking water. That means: You cannot reach a clean drinking water source within half an hour of walking from your place of residence. The experts fear that climate change will worsen the problem. Their prognosis: by 2025, half of the world's population will live in arid areas.

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