Scientists have created low-cost material to remove heavy metals from water


2021-06-22 14:20:55

Credit: NUST MISiS

Credit: NUST MISiS

Scientists from the National University of Science and Technology “MISiS” (NUST MISIS) as part of international group of researches has created nanomaterials for groundwater treatment for drinking water supply. According to the researchers, the new material is three times more efficient than analogues, and requires 100 times less energy to produce. The results were published in the Journal of Environmental Chemical Engineering.

Water from groundwater sources on the territory of Russia, CIS and many other countries often contains iron and manganese 100-200 times above sanitary standards, specialists of the NUST MISIS said. Poisoning with these metals disrupts the nervous system, functions of liver, digestive system and causes cancer and other acute pathologies.

To remove excess dissolved metals, they must be oxidized until insoluble, scientists explained. Nowadays a variety of materials for water treatment are available, but they are all very expensive, while their production technology is complex and harmful for the environment.
The specialists of the Research Center of Engineering Ceramic Nanomaterials of the NUST MISIS together with their colleagues have discovered a new way of obtaining filtering materials for purification of water from metals, which, according to them, excels analogues for all indicators.
“The iron-containing sediment taken from the active water decontamination stations was dissolved in nitric acid, and the silicate mineral granules - fire-resistant grog (clay), were soaked in the resultant solution. The granules were then placed in a heated furnace where self-propagating high-temperature synthesis took place. Our approach allows to reduce energy consumption more than 100 times in comparison with analogues, and to reduce the consumption of reagents up to 10 times”, - Director of the Research Center of Engineering Ceramic Nanomaterials of the NUST MISIS Dmitry Moskovskikh said.

After modification, iron oxide nanoelements are formed on the surface of the grog, which contribute to the active oxidation of iron and manganese in water. According to the authors of the research, the materials received are 3.5 times more efficient than the analogues used today at water treatment stations.

Scientists have also shown that it`s possible to use industrial waste both as a source of grog and as a source of metals for nano-coating. Non-toxic by-products are formed during the production of the material, the NUST MISIS specialists emphasized.

“The new technology can be used as a basis for the creation of multifunctional coatings for efficient removal of poisonous substances from groundwater and control of biofouling. This will make it possible to ensure the high quality of drinking water and to lower the use of chlorine for its decontamination», - the main author of the research Valentin Romanovsky said.

Specialists from the Institute of General and Inorganic Chemistry (Belarus), the University of Virginia (USA), the Istanbul University (Turkey), the University of Limerick (Ireland), the Royal Institute of Technology (Sweden) also took part in the research.