Synthesis of ZSM-5 zeolite from fly ash and its adsorption of phenol, quinoline and indole in aqueous solution

Abstract

This work tries to synthesize ZSM-5 zeolite using fly ash (FA) by hydrothermal method and study the adsorption effect of the zeolite on phenol, quinoline and indole in aqueous solution. The zeolites were characterized with x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray fluorescence (XRF), fourier transformation infrared (FTIR) and N 2 adsorption-desorption isotherm. The characterization results showed that HZSM-5 zeolite was successfully synthesized. The higher mass ratio of sodium carbonate to fly ash during melting is beneficial to improve the purity of ZSM-5 zeolite and its removal rate of organic matters. These results have been confirmed by XRD and principal component analysis (PCA). The adsorption process of phenol, quinoline and indole in aqueous can be well described with the double exponential kinetic model. The adsorption capacity of ZSM-5 zeolite for phenol, quinoline and indoles can be up to 24.41 mg g −1 , 35.99 mg l −1 and 34.05 mg g −1 respectively, and the removal rates can reach up to 82.80%, 84.86% and 83.20% respectively. The optimal pH value for adsorption ranges from 5 to 7.

Zeolite ZSM‐5 synthesized from natural silica sources and its applications: a critical review

“…Fly ash is one of the principal wastes produced by coal burning in power plants. Because the major components of fly ash are silica and alumina that are chemically comparable to the components of zeolite, several studies have focused on converting fly ash to ZSM‐5 zeolite 80‐82 . Rice husk ash is an agricultural by‐product with a high content of amorphous SiO 2 that can be collected when the husks are treated with alkali solutions 84,87 .…”

“…From 2018 to present, scientists have paid close attention to the synthesis and application of ZSM‐5 from fly ash, as evidenced by the growing number of publications. Some research has focused on the optimization of crystal formation 81 or the external surface phenomena in the dealumination and desilication of ZSM‐5, 142 while others concentrated on the catalytic 83,125,143,144 or adsorptive performance 80,90,126,145,146 . To be more specific, ZSM‐5 has been successfully used to eliminate volatile organic compounds (VOCs) or hazardous substances in aqueous solutions via adsorption.…”

“…During the 50 h of experimental assessment of the catalytic convertor, no significant deactivation of the convertor was found 125 . Other VOCs or hazardous compounds efficiently eliminated by ZSM‐5 were phenol quinoline, indole, benzene, toluene, and anionic dyes 80,90,126 …”

“…69,[76][77][78][79] Although several studies have reported using clays as Si/Al precursors, there has been little progress in directly producing ZSM-5 zeolite from abundant natural resources, such as kaolinite. Furthermore, fly ash [80][81][82][83] and biomass plant ash (rice husk, silica fume, water reed) [84][85][86][87][88][89][90] containing high concentrations of Si or Al have been effective in the production of ZSM-5 zeolite. Other natural aluminosilicate minerals, such as silicon-rich diatomite, 91,92 aluminum-rich rectorite minerals, 85,[91][92][93] illite clay, 94,95 natural zeolite, 79,96 palygorskite, 97 and perlite, 98 have also been reported as novel, cost-effective, and eco-friendly precursors for the synthesis of ZSM-5 zeolite.…”

CuO, MgO, and ZrO₂ Loading on HZSM5 by Deposition-precipitation: Study of Crystallinity, Specific Surface Area, and Morphology

“…However, the metal addition to the support (solid acid) often affects the catalyst's crystallinity, specific surface area, and morphology. Meanwhile, several studies showed an excellent catalyst gives a good performance related to the high crystallinity [3], high surface area [4], porous morphology [5,6], and metal distribution on support [5,7]. Therefore, it is crucial to study the effects of metal addition to support the bifunctional catalyst of direct DME synthesis.…”