[Oxidation of cationic red 3R in water with H2O2 catalyzed by mineral loaded with Fe/Co]

Catalyst supported on pyrite was prepared by the impregnation method to enhance the activity of catalyst and characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). Some Fe2O3 and CoFe2O4 species were formed on the surface of pyrite. Synthetized catalyst was used to catalyze H2O2 oxidative discoloration of azo dye. Under the conditions of the catalyst adding dosage of 3 g x L (-1), H2O2 adding dosageof 0.3 mL x L(-1), and the oxidation reaction timeof 1 h, results showed that about 99.8% of color removal rate and 58.4% of TOC removal rate could be achieved. The active ingredients of catalyst were Fe2O3 and CoFe2O4. Hydroxyl radical was determined during the reaction by ESR technology, the chromophore of dyes could be destroyed with 1 min, and small molecular substances might be produced during the process according to the spectrum analysis. Reaction with wide pH ranges is beneficial to overcome the limitation of traditional Fenton reactions. This technology might be used as a potential alternative for treatment of recalcitrant wastewater.