Resource Recovery from Oil-Contaminated Soil Through Organic Phase Extraction for Bitumen-like Material Production

Oil-contaminated soils represent a significant environmental challenge due to the presence of petroleum hydrocarbons and associated pollutants. At the same time, such materials may contain valuable hydrocarbon-rich organic fractions that can potentially be recovered and reused. In this study, the organic phase extracted from oil-contaminated soil was investigated as a secondary hydrocarbon resource for the production of bitumen-like materials. The extracted organic phase was subjected to thermal oxidation to obtain a bitumen-like material, followed by modification using road bitumen (BND 50/70) and an SBS polymer. The resulting bitumen-like material exhibited improved performance after modification, with the softening point increasing from 32.1 to 40.6 °C, the rotational viscosity from 3.11 to 101.5 Pa·s, and enhanced high-temperature rutting resistance. The structural and compositional characteristics of the obtained materials were analyzed using FTIR spectroscopy, nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and Saturates, Aromatics, Resins, and Asphaltenes (SARA) fractionation. Physicomechanical and rheological properties were evaluated using penetration, softening point, rotational viscosity, and dynamic shear rheometer (DSR) measurements. The results indicate the presence of aliphatic and aromatic hydrocarbon-rich structures characteristic of petroleum-derived materials. Modification with road bitumen and SBS resulted in redistribution of SARA fractions and improved physicomechanical and rheological properties, including increased softening point, higher viscosity, and enhanced resistance to permanent deformation at elevated temperatures. Overall, the obtained results demonstrate that oil-contaminated soils can be considered a promising secondary source of hydrocarbon-rich raw materials. The proposed approach combines waste remediation with resource recovery and supports the development of sustainable technologies for the utilization of petroleum-containing wastes within a circular economy framework.