OREANDA-NEWS   Russian scientists have found out that the plant biomass of Sosnovsky hogweed can be successfully used to create sorbents that purify water from radionuclides. The results of the study, supported by a grant from the Russian Science Foundation (RNF), are published in the journal Carbon Resources Conversion.

The nuclear industry is one of the most reliable and efficient ways to generate energy. However, radionuclides — radioactive elements formed during nuclear reactions — enter the environment and lead to its pollution. This may occur as a result of human activity (fertilization of agricultural lands, heavy industry, development of mineral deposits, disposal of radioactive waste, radiation emissions from nuclear power plants), or it may be due to natural causes — radioactive radiation of elements of the Earth's crust, gamma radiation from space. Thus, uranium — one of the most common long—lived radionuclides - gets into the soil, accumulates in it, pollutes underground and surface waters and, dissolving in them, spreads across lakes, rivers and seas. Further, radionuclides can enter living organisms, including humans, which can cause damage to vital organs and oncological diseases. In this regard, experts are looking for an effective method of cleaning water from radionuclides.

Scientists from the Federal Research Center "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences" (Syktyvkar), the Research Institute of Synthetic Rubber named after Academician S. V. Lebedev (St. Petersburg) and the Northern (Arctic) Federal University named after M. V. Lomonosov (Arkhangelsk) have created nanocarbon adsorbents capable of absorbing radioactive elements from liquid media and retaining them. As a raw material, the researchers used the biomass of Sosnovsky hogweed, natural lignin — a polymer compound contained in the cells of terrestrial plants, as well as technical lignin — a by-product of deep chemical processing of wood.

Initially, the hogweed was brought to central Europe to be used as livestock feed, but the plant filled all the free spaces along the roads and in the forests, destroying the local flora. Moreover, it turned out to be dangerous for humans. The stems and pollen of hogweed contain poisonous compounds — furanocumarins, which cause burns, blindness and damage to the respiratory system. The use of this plant as a raw material for nanomaterials will help partially limit its spread.

The authors obtained a porous sorption material from a mixture of powders of the original plant biopolymers with the addition of an oxidizer using the latest technology of self-propagating high-temperature synthesis, that is, they synthesized a filter material that was given a porous structure by treatment with nitrogen compounds and cooling.

Experiments have shown that the new nanocarbon adsorbent retains uranium well. Thus, about 70% of these radionuclides are not washed out by water or other solvents. Scientists also found out that such a material is able to adsorb mycotoxin T-2 — a product of the vital activity of mold fungi, which can accumulate in cereals, fruits, vegetables, nuts and cause serious diseases.