HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF NANO SIZED ZSM-5 AND THEIR EFFECT ON THE DECOLORIZATION OF INDIGO CARMINE DYE

Abstract

Silica sources can influence different effects of ZSM-5 crystallization and it leads to change in the properties of the final product. The crystallinity of nanosized ZSM-5 zeolite from precursors mixtures containing different silica sources, e.g. tetraethylorthosilicate (TEOS), colloidal silica (CS), silicic acid(SA) and fumed silica(FS) have been studied. The produced samples are investigated using XRD, SEM, FT-IR, pyridine adsorption and N2 adsorption measurements. XRD results show that the product obtained by different silica sources is nano sized ZSM-5 phase. SEM results show that silica sources influences on shape of the produced ZSM-5; the sample which was prepared by silicic acid crystallized in spherical shape crystals, the samples which was prepared by TEOS crystallized in cubical shape crystals, the sample which was prepared by colloidal silica crystallized in spherical shape crystals with smaller aggregated but the sample which was prepared by fumed silica crystallized in round shape crystals. N2 adsorption results show thatsilica sources influences on pore diameter and pore volume of the produced ZSM-5.The adsorption of indigo carmine dye by ZSM-5 has been studied. It was found that the synthesized zeolite by SA exhibited significantly higher adsorption capacity for indigo carmine than other ZSM-5 states due to the difference in morphological properties. The optimum ZSM-5 loading is 1 g at pH 4 after 180 min.