Innovative Sulfur-Modified TiO₂-Loaded SiO₂ Nanocomposite: Unveiling Superior Removal Performance of Contaminants in Waste Oil

Corrosive sulfur compounds and trace moisture were key factors causing the rapid deterioration of finished mineral oils. In power systems, insulating oil contaminated by such substances not only threatens the stable operation of power equipment but also transforms into hazardous waste due to performance degradation. This study innovatively developed a sulfur-modified TiO₂-loaded SiO₂ nanocomposite (S-nTDSGS) adsorbent, which was comprehensively characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and specific surface area analysis. Using dibenzyldisulfide (DBDS) as a model contaminant, desulfurization tests following national standards showed that S-nTDSGS achieved a desulfurization efficiency of 88.54% for oils with an initial DBDS concentration of 100 μg/mL, confirmed by significantly reduced copper strip corrosion. Karl Fischer method tests demonstrated an 83.94% dehydration rate for oils with an initial water content of 200 μg/mL, stabilizing the water content below 35 μg/mL in compliance with national standards. Comparative studies with SiO₂, nano-TiO₂, and other adsorbents showed that S-nTDSGS outperformed in both desulfurization and dehydration efficiencies and effectively adsorbed dark-colored contaminants, as evidenced by color comparisons. Overall, the S-nTDSGS adsorbent exhibits excellent pollutant removal performance for insulating oils, demonstrates great potential in mineral oil purification, and holds promise as an innovative solution for hazardous waste treatment and oil recycling.