STUDY OF THE MECHANISM OF DECOLORIZATION OF THE AZO DYE ORANGE G IN AQUEOUS SOLUTION VIA A HETEROGENEOUS UV/FENTON-LIKE REACTION CATALYSED BY IRON PILLARED MONTMORILLONITE

The azo dye Orange G (OG) in wastewater was treated via heterogeneous UV/Fenton-like reaction catalysed by a highly catalytic active iron pillared montmorillonite (Fe-Mt). The results showed that the pH 3.0, H2O2 20.0 mmol/L and Fe-Mt 1.0 g/L are the optimum conditions for the OG decolorization (i.e., 99.7% after 180 min) if the temperature and OG concentration were kept constant at 30℃ and 50 mg/L, respectively. Under the above conditions, the OG decolorization followed the two-stage pseudo-first-order kinetics in the heterogeneous UV/Fenton-like reaction system.