A new composite material from the so-called MOF class removes heavy metals from water much more efficiently and economically than the techniques available today. There are currently around a billion people around the world who supply themselves with water contaminated with heavy metals, and the problem could get worse due to the increasing increase in their use in industrial processes.
Credits Pixabay
A new composite material is able to remove heavy metals from water simply, quickly and economically. Its development, carried out by researchers and described on "ACS Central Science", could finally provide drinking water to the approximately billion people who today are exposed to serious health risks related to use of water contaminated by substances such as lead and arsenic.
The sources of heavy metals that can contaminate the water are innumerable: lead, for example, has been used, and sometimes it is, to produce paints, ceramic enamels, jewelry, toys and pipes. Furthermore, the increase in the use of heavy metals in various industrial processes risks increasing the number of people potentially exposed to them.
By contrast, the methods currently on the market to remove heavy metals from water networks are expensive both economically and as energy consumption, as well as being inefficient. Moreover, they are often single-use or difficult to regenerate and can produce large amounts of toxic waste as waste.
Wendy L. Queen and her colleagues looked at particular materials called metal organic framework(MOF), porous materials with an extremely high internal surface, whose reticular structure is punctuated by metallic "nodes" able to attract different substances to itself. The researchers realized a MOF / polymer composite material capable of capturing heavy metals.
Credits Pixabay
In the experiments conducted on solutions with lead levels similar to those found in Flint, Michigan, (the city became famous in 2016 for the high concentrations of lead in water supply), the material showed to remove 40 percent of its weight in lead, quickly reducing lead concentrations to 2 parts per billion, which is the limit set by the EPA (the US Environmental Protection Agency) for water potability .
In other tests, the authors removed lead from samples of Rhone water, the Mediterranean Sea and a sewage treatment plant in Switzerland.
The new material has shown even greater efficiency with mercury, which removes more than 1.6 times its weight. And it has proved to be stable both in fresh and marine waters and resistant to fouling even in the presence of high concentrations of common organic substances, remaining also regenerable - without the use of other toxic products - for many cycles of use.
