Abstract
Soil contamination caused by accidental oil spills represents a serious environmental risk, particularly in industrial, transportation-related, and storage areas. In this study, waste rigid polyurethane foam derived from refrigeration insulation was investigated as a low-cost sorbent material for potential application in oil spill mitigation and soil protection. The combined effects of mechanical piece size reduction and mild surfactant-based surface modification were evaluated using different hydrocarbon liquids, including crude oil, diesel fuel, and used motor oil. The rigid polyurethane foam was processed into three piece size fractions, and selected samples were modified with nonionic surfactants, namely Span 80 and alkyl polyglucoside.The results showed that piece size reduction strongly influenced oil sorption performance, with the smallest particle fraction exhibiting the highest sorption capacity for all tested oils. Surface modification further improved oil uptake, particularly in the case of Span 80-treated samples. The highest sorption capacity was obtained for the 2–5 mm fraction treated with Span 80, reaching 12.49 g/g for crude oil. The observed trends suggest that sorption performance is affected by the combined influence of piece size, oil viscosity, surface affinity, and retention during drainage.Although the present work confirms the potential of mechanically processed and surface-modified waste rigid polyurethane foam as an oil sorbent, the proposed mechanisms related to opened cell structures and surfactant-induced wettability changes require further confirmation by detailed structural and surface characterization. The study provides a practical preliminary basis for the valorization of rigid polyurethane insulation waste in oil spill remediation and highlights key directions for further development, including statistical validation, sorption kinetics, reusability, oil/water selectivity, and testing under realistic environmental conditions.