1,4?Dioxane Removal using the Sono Fenton Reaction System

초록

We report the successful removal of 1,4 dioxane (1,4?D, arecalcitrant and non?degradable solvent stabilizer), by the sono?Fenton process using nanoscale zero?valent iron (core?shellnanowires, nZVI) or microscale zero?valent iron (mFe0) as a method for long?term wastetreatment. The time?dependent concentrations of 1,4?D, H2O2, leaching ionic Fe and pH were measured as a function of zero?valent iron (ZVI) dosage. The optima dosage of nZVI and mFe0 in the sono?Fenton process were found to be 0.1 g/L and 0.5 g/L, respectively, holding the leaching ionic Fe concentration (below 2 mg/L). In addition, The large surface area of nZVI facilitated a fast phase change from nZVI to iron oxide, maghemite(？？?Fe2O3)/magnetite (Fe3O4), which resulted in the loss of catalytic activity, although Fe0 was conserved. On the other hand, the mFe0 was only partially transformed to iron oxide. The degradation mechanism took place entirely on the ZVI surface, but the initial step of the homogeneous sono?Fenton reaction involved leaching of Fe ions (total Fe2+ and Fe3+ ions). Consequently, the ratio of catalyst size to surface area is important for the efficiency of degradation of aromatic toxic compounds via the sono?Fenton system. We demonstrate the sono?Fenton system with ZVI is suitable for wastewater treatment.