| In this dissertation, the effect of hydrogen peroxide as well as its complex with different adsorption catalysts (molecular sieve, Al2O3, bentonite and titanium pillared bentonite) on the simulated concentrated malachite green (MG) dye wastewater in the presence of microwave irradiation was studied. The removal capacity of each system was discussed compared with the methods using electric stove or sunlight. The effect of all the possible conditions including H2O2, adsorption catalysts, and the irradiation time on the decolorization efficiency of MG were also discussed . Decolorization kinetics and mechanisms of malachite green dye solution were studied by HPLC, UV-VIS spectra, FTIR, 1H-NMR and XRD.The experimental results showed that high decolorization efficiency and fast decolorization speed were obtained when the solution of MG was radiated by microwave in the presence of H2O2 or the complex system of H2O2 and adsorption catalysts. The microwave/H2O2/adsorption catalysts systems were proved to be more effective compared to any other condition. More than 99.0% of MG (initial dye concentration 400mg.L-1) was removed when it was irradiated by microwave for 8 minutes. The decolorization ratio was testified to be increased with the irradiation time, and the dosage of H2O2 and the adsorption catalysts. The degradation reactions of all the studied systems were comformed to be pseudo first-order reactions, except for the case that microwave/H2O2/Al2O3 synergestically acted on MG dye wastewater, which was proved to be pseudo zero-order reaction.Our results showed that all the degradation products obtained by different methods were basically the same, however, the degradation mechanisms were quite different. The·OH free radical is a key role in the process of degradation in all cases.
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