RESUMO
The degradation efficiencies of dimethyl phthalate (DMP) by O3, O3/H2O2, Ti(IV)/O3 and Ti(IV)/O3/H2O2 were investigated under acidic conditions. The results indicated that Ti(IV)/O3/H2O2 was the best system with the highest degradation efficiency and mineralization rate of DMP, and the highest utilization rate of ozone at pH 2.8. The apparent rate constants of DMP degradation by O3, O3/H2O2, Ti(IV)/O3 and Ti(IV)/O3/H2O2 under the same conditions were 3.96 x 10(-4) s(-1), 9.54 x 10(-4) s(-1) 1.07 x 10(-3) s(-1) and 6.41 x 10(-3) s(-1), respectively. The ozone utilization rate of Ti(IV)/O3/H2O2 was improved by 6.51% compared with that of ozonation alone. The experimental results showed that the optimized concentrations of Ti(IV) and H2O2 were 1.4 mg x L(-1) and 10 mg x L(-1), respectively. According to the results of gas chromatography-mass spectrometry (GC/MS) and ion chromatography analysis, the possible reaction pathway of DMP degradation by Ti(IV)/O3/H2O2 was proposed and discussed.
