Sodium Dodecylbenzenesulfonate Promotes Fe@Fe₂O₃ Electron Transfer and Induces Free-Radical Conversion to Enhance Tetrabromobisphenol A Degradation

The solubility of hydrophobic pollutants in the aqueous phase affects the degradation efficiency of the pollutants, and cosolvents are usually used to enhance the solubility of hydrophobic pollutants; however, the effect of cosolvents on the pollutant degradation process is not clear. This study constructed a sodium dodecylbenzenesulfonate (SDBS)/Fe@Fe2O3/PMS system for the efficient removal of tetrabromobisphenol A (TBBPA). SDBS increases the adsorption of oxygen species on the surface of Fe@Fe2O3, disrupts the dense oxide layer, and promotes the release of iron ions from the core. Kinetic results indicate that the degradation rate constant of TBBPA increases by 87.5 times in the presence of SDBS, and the system is minimally affected by environmental factors, making it broadly applicable. SDBS enhances the dissolved oxygen in the system, promotes the conversion of hydroxyl radicals (•OH) into superoxide radical (O2•–) and singlet oxygen (1O2), and facilitates the transformation of TBBPA into TBBPA radical cations through electron transfer, which then undergoes debromination, hydroxylation, and demethylation to form small molecular degradation products. The dual role of SDBS enables the reutilization of aged ZVI, making it a promising technology for pollutant remediation.