Light-assisted 1,4-dioxane degradation

The oxidative degradation induced by light of 1,4dioxane been investigated in homogeneous solution in the presence of inorganic peroxides (either hydrogen peroxide or peroxydisulfate) and under heterogeneous photocatalytic conditions in the presence of titanium dioxide. The effect of photon energy spectral distribution, pH, O2 and scavengers has been examined. The degradation mechanism involves common intermediates. Ethylene glycol diformate was observed as the main intermediate. In the presence of UV light peroxydisulfate showed high degradation efficiency. A tentative chain radical oxidation mechanism is postulated. The distinctive features of heterogeneous photocatalytic treatment were the good efficiency under simulated solar spectrum and the absence of inhibition of the degradation rate by HCO3−. The presence of peroxydisulfate enhances the TiO2 photocatalytic degradation rate.