Sodium Dodecylbenzenesulfonate\nPromotes Fe@Fe<sub>2</sub>O<sub>3</sub> Electron Transfer and Induces\nFree-Radical Conversion\nto Enhance Tetrabromobisphenol A Degradation

The solubility of hydrophobic pollutants in the aqueous\nphase affects\nthe degradation efficiency of the pollutants, and cosolvents are usually\nused to enhance the solubility of hydrophobic pollutants; however,\nthe effect of cosolvents on the pollutant degradation process is not\nclear. This study constructed a sodium dodecylbenzenesulfonate (SDBS)/Fe@Fe<sub>2</sub>O<sub>3</sub>/PMS system for the efficient removal of tetrabromobisphenol\nA (TBBPA). SDBS increases the adsorption of oxygen species on the\nsurface of Fe@Fe<sub>2</sub>O<sub>3</sub>, disrupts the dense oxide\nlayer, and promotes the release of iron ions from the core. Kinetic\nresults indicate that the degradation rate constant of TBBPA increases\nby 87.5 times in the presence of SDBS, and the system is minimally\naffected by environmental factors, making it broadly applicable. SDBS\nenhances the dissolved oxygen in the system, promotes the conversion\nof hydroxyl radicals (<sup>•</sup>OH) into superoxide radical\n(O<sub>2</sub><sup>•–</sup>) and singlet oxygen (<sup>1</sup>O<sub>2</sub>), and facilitates the transformation of TBBPA\ninto TBBPA radical cations through electron transfer, which then undergoes\ndebromination, hydroxylation, and demethylation to form small molecular\ndegradation products. The dual role of SDBS enables the reutilization\nof aged ZVI, making it a promising technology for pollutant remediation.