Decontamination of Groundwaters Containing tert-Butyl Methyl Ether and Aromatic Hydrocarbons (BTEX) by Photolysis of H2O2

A highly contaminated groundwater (235 mg l–1 MTBE and 112.6 mg l–1 BTEX) was subjected to UV/H2O2 photolysis at ambient temperature in a batch UV reactor. GC/MS analysis showed that BTEX are completely destroyed while the degradation of MTBE proceeds via tert-butyl formate as the main reaction byproduct. High MTBE conversions (> 99.9 %) were obtained under conditions of the zero-order reaction with respect to hydrogen peroxide. The photolysis was of the first order with respect to both of MTBE and BTEX. The observed negative effect of BTEX on the rate of MTBE degradation was reduced by pretreatment of the groundwater with activated bentonite or by biodegradation. The pretreatment ensured short decontamination times and high MTBE degradation > 99.95 % ).