According to international organizations, up to 2 billion people in the world are deprived of access to clean drinking water. Meanwhile, we are surrounded by oceans filled with salty water that is not suitable for human consumption. The Australian scientists have made a discovery that can become the solution to the problem of desalination of salty water. They have created a device that uses Metal-Organic Framework (MOF) and sunlight to obtain freshwater in just 30 minutes.
A research team from Australia’s Monash University has created a special MOF, which is called PSP-MIL-53, by integrating MIL-53 (material for the adsorption of water and carbon dioxide molecules) and Self-protonating spiropyran (PSP). One of the features of MOF’s spongy structure is its enormous internal surface area. For example, if we deal with PSP-MIL-53 volume of one teaspoon, its inner surface area will be comparable in size to that of a football field.
The operating principle of the PSP-MIL-53 desalination system lies in the absorption of salt ions from salty water upon contact of the liquid with the surface of the Nano Sponge. During testing, water contacted with MOF for 30 minutes and purification was carried out from an initial level of total dissolved solids (TDS) of 2233 ppm (foreign matter per million) to 500. Meanwhile, the WHO drinking water quality standard is 600 ppm.
After just four minutes in the sun, the MOF was ready for reuse. According to scientists, 1 kg of MOF PSP-MIL-53 is capable of desalinating 139.5 liters in a day. At the same time, renewable solar energy will be required to clean the installation. The surplus of this energy is precisely in the area, where the problem with the shortage of freshwater is the most serious.