Characterization and environmental application of a Chilean natural zeolite

Englert, Alexandre Hahn; Rubio, J.

doi:10.1016/j.minpro.2004.01.003

Cited by 194 publications

(91 citation statements)

References 22 publications

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“…In the same way, an increase of the adsorbed nitrogen was observed for values of P/P 0 close to 1, possibly due to the presence of mesopores. Results obtained here are in accordance with those reported elsewhere [23,24]. X-ray powder diffraction (XRD) patterns of natural and modified zeolite samples have been previously reported [25,26].…”

Section: Physical-chemical Characteristics Of Natural and Modified Zesupporting

confidence: 92%

Catalytic Ozonation of Toluene Using Chilean Natural Zeolite: The Key Role of Brønsted and Lewis Acid Sites

et al. 2018

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Abstract:The influence of surface physical-chemical characteristics of Chilean natural zeolite on the catalytic ozonation of toluene is presented in this article. Surface characteristics of natural zeolite were modified by acid treatment with hydrochloric acid and ion-exchange with ammonium sulphate. Prior to catalytic ozonation assays, natural and chemically modified zeolite samples were thermally treated at 623 and 823 K in order to enhance Brønsted and Lewis acid sites formation, respectively. Natural and modified zeolite samples were characterised by N 2 adsorption at 77 K, elemental analysis, X-ray fluorescence, and Fourier transform infrared (FTIR) spectroscopy, using pyridine as a probe molecule. The highest values of the reaction rate of toluene oxidation were observed when NH4Z1 and 2NH4Z1 zeolite samples were used. Those samples registered the highest density values of Lewis acid sites compared to other samples used here. Results indicate that the presence of strong Lewis acid sites at the 2NH4Z1 zeolite surface causes an increase in the reaction rate of toluene oxidation, confirming the role of Lewis acid sites during the catalytic ozonation of toluene at room temperature. Lewis acid sites decompose gaseous ozone into atomic oxygen, which reacts with the adsorbed toluene at Brønsted acid sites. On the other hand, no significant contribution of Brønsted acid sites on the reaction rate was registered when NH4Z1 and 2NH4Z1 zeolite samples were used.

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Section: Physical-chemical Characteristics Of Natural and Modified Zesupporting

confidence: 92%

Catalytic Ozonation of Toluene Using Chilean Natural Zeolite: The Key Role of Brønsted and Lewis Acid Sites

et al. 2018

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“…As shown in Figs. 5a-5c, the adsorption rates of MB on 0.08 g of unmodified zeolite and 2% SDBS-and 3% SDS-modified zeolites can reach 98.22, 99.44, and 98.47%, respectively; and the maximum MB adsorption on unmodified zeolite was about 35 mg/g, which is comparable to other studies [25]. For OII (Figs.…”

Section: Influence Of Adsorbent Amount Used On Mb and Oii Adsorptionsupporting

confidence: 83%

Adsorption of methylene blue and orange II onto unmodified and surfactant-modified zeolite

Jin

Jiang

Shan

et al. 2008

Journal of Colloid and Interface Science

195

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“…The maximum ammonium sorption capacity of clinoptilolite rich mineral specimen was found as 9.47 mg/g. Ammonium sorption capacity values were reported in the range of 6-30 mg/g for clinoptilolite rich mineral from various origins (Englert and Rubio, 2005;Lei et al, 2008;Saltalı et al, 2007;Sarıoğlu, 2005;Sprynskyy et al, 2005;Vassileva and Voikova, 2009;Wang et al, 2007;Weatherley and Miladinovic, 2004;Widiastuti et al, 2011).…”

Section: Sorption Isothermsmentioning

confidence: 99%

Ammonium sorption by Gördes clinoptilolite rich mineral specimen

Erdoğan

Ülkü

2011

Applied Clay Science

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Experimental and theoretical works were performed for the estimation of the effects of pH, initial concentration, agitation speed, particle size and temperature on the ammonium sorption by local clinoptilolite rich mineral specimen. The kinetic sorption data were analyzed using external mass transfer, intraparticle diffusion, pseudo first and second order kinetic models. Diffusion model results revealed that external film diffusion dominated at the very early stages of sorption process and then it was overcome by intraparticle diffusion. Pseudo-second order kinetic model correlated with the experimental data better than the pseudo first order kinetic model. Sorption isotherm model results indicated that the Langmuir isotherm fitted well to the experimental data. Thermodynamic parameters Gibbs energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were calculated. It was shown that the sorption process was exothermic and spontaneous. The value of the activation energy suggested that ammonium sorption by the clinoptilolite rich mineral specimen is likely due to physical interactions between the sorbent and the sorbate. Analysis of the cation exchange results revealed that ion exchange mechanism was not the only step which was effective in ammonium sorption.

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Characterization and environmental application of a Chilean natural zeolite

Cited by 194 publications

References 22 publications

Catalytic Ozonation of Toluene Using Chilean Natural Zeolite: The Key Role of Brønsted and Lewis Acid Sites

Catalytic Ozonation of Toluene Using Chilean Natural Zeolite: The Key Role of Brønsted and Lewis Acid Sites

Adsorption of methylene blue and orange II onto unmodified and surfactant-modified zeolite

Ammonium sorption by Gördes clinoptilolite rich mineral specimen

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