Photodecolorization of Eriochrome Black T using NiS-P zeolite as a heterogeneous catalyst.

NiS-P zeolite was prepared by ion exchange and precipitation procedures and it was characterized by FT-IR, SEM and thermal methods. The prepared composite was used as a catalyst in the photodecolorization process of Eriochrome Black T (E.B.T.) dye in aqueous solution under UV irradiation. The effect of key operating parameters such as catalyst dosage, temperature, initial concentration of the dye and initial pH of the solutions were studied on the decolorization process of dye. The primary objective was to determine the optimal conditions for each of the parameters. UV-vis spectrophotometric measurements were performed for the determination of decolorization and mineralization extents. The optimal operation parameters were found as follows: pH 9.1, 0.8 g L(-1) of catalyst loading and 40 ppm of dye concentration. The NiS particles out of zeolite framework did not show significant decolorization efficiency. The decolorization process obeyed first-order kinetics.