January 22, 2025

Oil spills worsen soil fertility in Siberia. Russian scientists have assessed the impact of oil pollution on the soil in the middle taiga of Western Siberia. The presence of petroleum products reduces the soil's ability to retain water and nutrients and leads to serious changes in soil pH. Podzolic soils are particularly affected by oil pollution. Deterioration of soil quality can lead to nutrient imbalances and adverse effects on plant growth. The results of the study will help in the development of effective strategies for solving environmental problems related to oil pollution. The results of the study are published in the journal Sustainability.

Oil pollution is a global environmental problem that has a devastating impact on ecosystems. For example, oil pollution of the soil, even in relatively low concentrations, alters the chemical, physical, biological and morphological properties of the soil, reduces the availability of nutrients and hinders the activity of soil organisms. The study of the impact of oil pollution on the environment is important for understanding and reducing their negative impact. Oil toxicity poses a long-term threat to ecosystem stability, so restoration requires an integrated approach combining biological and physical purification methods.

A team of Russian scientists, which included specialists from the Krasnoyarsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences, assessed the impact of oil pollution on soil in the middle taiga of Western Siberia. The experts studied the physical and chemical characteristics of the soil at new oil fields in remote areas of Western Siberia and how different types of soils react to oil pollution.

The researchers studied the effects of oil pollution on three types of soils: podzolic, sod-gley and alluvial in the middle taiga of Western Siberia in the Kondinsky district of the Khanty-Mansi Autonomous Okrug. This region suffers from both crude oil spills and pollution from its extraction and transportation. Under controlled laboratory conditions, scientists introduced oil into the soil in different doses: from moderate pollution of 50 grams per kilogram, to severe pollution of 150.

"It is important to understand the physical properties of soils, such as their ability to retain water, porosity, and density. They determine how suitable the soil is for plant growth and how resistant it is to external influences. When the soil is polluted with oil, its properties can change, and this affects how it will recover. It is necessary to understand these properties of the soil in order for the cleaning methods to be effective and the restoration to be successful," said one of the authors of the study, Alexander Shpedt, Doctor of Agricultural Sciences, Corresponding Member of the Russian Academy of Sciences, Director of the Krasnoyarsk Scientific Center SB RAS.

The results of the study showed that oil contamination of the soil leads to serious changes in its pH, ability to retain nutrients and water. Podzolic soils, which have less organic matter and a more acidic environment, have been particularly badly affected. The capacity of cation exchange, the ability to retain essential nutrients, in podzolic soils decreased fivefold with higher levels of pollution. Sod-gley and alluvial soils also experienced a negative impact, although to a lesser extent. Experts note that this raises concerns because it worsens the quality of the soil and can lead to an imbalance of nutrients, a decrease in microbial diversity and adverse effects on plant growth.

Experts also noted that the presence of petroleum products reduces the ability of the soil to retain water. Soils with low water retention capacity cannot provide sufficient moisture for plant growth. In addition, experts have found that the hydrophobic properties of petroleum products create water-repellent layers on the soil surface that prevent water from penetrating inside. This can lead to runoff, erosion, and deterioration of the soil structure. Studies have shown that soil properties begin to degrade after oil enters them at a concentration of 50 g/kg. This can seriously affect the hydrological properties of the soil, which will negatively affect the health of the soil and ecosystem.

In recent years, Russian oil companies have been developing new oil fields in remote areas of the Khanty-Mansiysk Autonomous Okrug. Therefore, the scientists also decided to find out how the modified synterol surfactant, which is used in oil production to treat bottomhole zones of wells and clean tanks and cargo tanks of ships from oil, affects the soil. Can this substance help to remove oil from polluted soil? It turned out that its use does not accelerate the decomposition of oil. Even after 35 days of treatment, the concentration of petroleum products in the soils remained virtually unchanged, and the rate of decomposition was low. This indicates the persistence of oil pollutants and the failure of the proposed methods, even for a long time, to eliminate high levels of pollution from the soil.

"The results show that cleaning strategies need to be tailored to specific soil types. Our research provides important insights for developing effective, adapted strategies to address environmental issues of oil pollution and promotes sustainable soil management practices for sensitive taiga ecosystems. In addition, the results of our work provide the basis for the development of specialized software for soil pollution analysis. The data can be used to build mathematical models for calculating and predicting changes in soil properties due to oil pollution. The integration of such models into analytical software will facilitate the assessment and forecasting of the effects of soil pollution in real time, support informed decision—making in the context of pollution management and restoration for taiga ecosystems," said Alexander Shpedt.

Specialists from Surgut State University, Siberian Federal University, Omsk State Technical University, Surgutneftegaz PJSC and Gazprom Transgaz Surgut LLC also participated in the study.

Sources:

https://www.mdpi.com/2071-1050/16/24/11204

https://scientificrussia.ru/articles/razlivy-nefti-uhudsaut-plodorodie-pocv-sibiri