Efficiency and Mechanism of Degradation of 2-Methylisoborneol(2-Mib) by O3/H2O2 in Water

Abstract-The research on efficiency and mechanism of removing the odor compound 2-MIB in water is performed by adopting the O₃/H₂O₂ technology. And in particular, the effects of addition manner, mol ratio, pH value of the solution and water quality etc, on the 2-MIB degradation are studied. And the intermediate products in the oxidative degradation of 2-MIB were analyzed by GC/MS. It is found that H₂O₂ can evidently promote the ozonation of 2-MIB in water by O₃. The degrading ratio of 2-MIB is 38.7% with O₃ separately oxidizing for 20min, and the degrading ratio of 2-MIB rises to 89.2% by adding adequate H₂O₂ in the same system. The optimal adding mol ratio of H₂O₂ to O₃ is about 0.6. A small amount of humic acid evidently promotes the degrading ratio of 2-MIB in O₃/H₂O₂ system. However, humic acid of high concentration significantly inhibits the oxidation process. The free radical scavenger, tertiary- butanol obviously inhibits the degradation of 2-MIB in O₃/H₂O₂ system. It is identified that the oxidation products of 2-MIB by GC/MS include 4-Hydroxy-1,7,7-trimethylbicyclo [2.2.1]heptan- 2-one, 1,7,7-Trimethylbicyclo [2.2.1] heptane-2,5-dione, 1,7,7-Trimethylbicyclo[2.2.1] heptan-2 -one etc. The mechanism of the whole oxidation process is deduced.