Degradation Pathways during the Treatment of Methyl tert-Butyl Ether by the UV/H₂O₂ Process

The application of the UV/H 2 O 2 process to the degradation of methyl tert -butyl ether (MTBE) in dilute aqueous solution resulted in the generation of tert -butyl formate (TBF), 2-methoxy-2-methyl propionaldehyde (MMP), formaldehyde, acetone, tert -butyl alcohol (TBA), and methyl acetate as primary byproducts. Other intermediates, such as carbonyl compounds (hydroxy- iso -butyraldehyde, hydroxyacetone, pyruvaldehyde) and organic acids (hydroxy- iso -butyric, formic, pyruvic, acetic, oxalic) were also detected and quantified during the irradiation. A good organic carbon balance is obtained throughout the treatment, indicating that almost all of the intermediates have been detected. The TOC pattern shows that eventually all the organic compounds are mineralized. Various analytical techniques, such as GC/MS, GC, IC, HPLC, and TOC analysis, were employed in order to identify and quantify the organic products. The detailed reaction mechanism proposed in this study for the degradation of MTBE by • OH-driven oxidation processes accounts for all observed intermediates and the high oxygen demand required for their complete mineralization.