Russia develops water purification technology using buckwheat husks

Scientists at the Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of the Russian Academy of Sciences (Novosibirsk) have created a new biosorbent from agricultural waste – buckwheat husks. It is designed to purify wastewater and natural water bodies from heavy metals, and in the future may be used in cartridges for home drinking water filters. This is reported by the official website of the Russian Academy of Sciences.

According to Tatyana Skripkina, senior researcher at the Institute of Solid State Chemistry and Mechanochemistry, the sorbent is processed buckwheat husks – a bio-renewable material that is available in large quantities in Russia but has not yet found widespread use.

"Buckwheat husks contain a lot of melanin, a polymer that can sorb metals. We have learned to modify it in such a way as to increase its sorption capacity, while ensuring that it remains stable and the resulting product can be loaded into purification systems. Our biosorbent should work both independently for local water purification and in other water-mobile systems for purifying running water," added Skripkina.

The production of the sorbent involves the mechanochemical processing of husks in special mills with the addition of a small amount of oxidants. This allows the melanin deep within the husk cells to remain available for binding heavy metals and other pollutants.

The technology was first tested in laboratory mills and is now being transferred to industrial plants that can process tonnes of product per hour. Buckwheat husks are a very cheap raw material, so the technology should remain affordable: only 5 per cent of oxidant needs to be added to produce the sorbent.

Biosorbent made from buckwheat husks can replace expensive ion-exchange resins in home filter cartridges. There is also evidence that melanin can combat bacterial contamination, but this area requires further research.