Ecologists of the Perm Polytechnic University have developed a technology that will help restore the fertility of soils contaminated with oil products and heavy metals. official website of the organization.
They suggested using soda sludge for this purpose and proved their effectiveness. The development will allow not only to improve the state of the environment, but also to utilize lime waste, reducing the consumption of natural raw materials.
— Heavy metals and oil products are the main soil pollutants in urban areas: closed industrial enterprises; lands that are removed from the sanitary protection zones adjacent to highways and production facilities. For reclamation and restoration of soil fertility, lime ameliorants and fertilizers can be used. We proposed to use soda production waste for this. This will help save natural raw materials,” says Elena Kalinina, Associate Professor of the Department of Environmental Protection at the Perm Polytechnic University, Researcher at the Laboratory for Rational Nature Management and Nature-Like Technologies, Candidate of Technical Sciences.
Scientists conducted a series of experiments to evaluate the physicochemical, physico-mechanical and toxicological properties of soda sludge. The researchers found that it has the properties of an ameliorant. Ecologists have proposed using the sludge for the reclamation of disturbed lands. They proved on soil samples from the territory withdrawn from the sanitary protection zone of an oil refinery that the use of sludge leads to a decrease in the phytotoxicity of contaminated lands. After the introduction of sludge into the soil in the amount of 1-3 g per 1 kg, the germination of plants increased, as well as the length of their ground parts and roots.
According to Perm ecologists, heavy metals and oil products worsen the agrochemical and agrophysical characteristics of soils, increase their phytotoxicity, and negatively affect biochemical processes and the microbial community.
— Soil pollution with oil and heavy metals leads to a decrease in the number of Azotobacter bacterium colonies. After introducing the sludge from soda production into the soil at a dose of 1-3 g per 1 kg, we found that the number of bacterial colonies increased by 3 times. The total number of microorganisms also increased. At the same time, it is important to prevent alkalization of the soil and maintain the optimal content of water-soluble salts,” explains the head of the Department of Environmental Protection of the Perm Polytechnic University, researcher at the Laboratory for Environmental Management and Nature-Like Technologies, Doctor of Technical Sciences, Professor Larisa Rudakova.
Scientists have found that the most safe in terms of physicochemical and toxicological properties are sludge with a particle size of less than 0,1 mm. They meet the requirements of GOST, which apply to lime ameliorants.
According to the researchers, the technology will help improve the environment, recycle industrial waste and reduce the consumption of natural resources.