The acidity of dealuminated clinoptilolite investigated by DSC, DTA and TG methods

Grejtak, F.; Horváth, I.; Kubranová, M.; Krajčovič, Jozef

doi:10.1016/0040-6031(92)80136-k

Cited by 5 publications

(3 citation statements)

References 7 publications

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“…The surface area and porosity of natural zeolites can be further enhanced by nano-milling of raw materials to achieve homogeneous particle morphology and sizes in a range of submicron to nano-meter (Box 1). Moreover, acid treatment can significantly increase the surface area of natural zeolites as reported in many studies [28][29][30]. This enhanced surface area and porosity of natural zeolites can improve its functioning in most of the WTE applications, hence optimizing the overall processes.…”

Section: Bet Surface Area Pore Size and Volume Of Natural Zeolitesmentioning

confidence: 92%

The potential of Saudi Arabian natural zeolites in energy recovery technologies

Nizami

Ouda

Rehan

et al. 2016

Energy

111

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Energy consumption in kingdom of Saudi Arabia (KSA) is growing rapidly due to economic development with raised levels of population, urbanization and living standards. Fossil fuels are currently solely used to meet the energy requirements. The KSA government have planned to double its energy generating capacity (upto 120 GW) by 2032. About half of the electricity capacity of this targeted energy will come from renewable resources such as nuclear, wind, solar, waste-to-energy (WTE) etc. Natural zeolites are found abundantly in KSA at Jabal Shamah occurrence near Jeddah city, whose characteristics have never been investigated in energy related applications. This research aims to study the physical and chemical characteristics of natural zeolite in KSA and to review its potential utilization in selected WTE technologies and solar energy. The standard zeolite group of alumina-silicate minerals were found with the presence of other elements such as Na, Mg and K etc. A highly crystalline structure and thermal stability of natural zeolites together with unique ion exchange, adsorption properties, high surface area and porosity make them suitable in energy applications such as WTE and solar energy as an additive or catalyst. A simple solid-gas absorption system for storing solar energy in natural zeolites will be a cheap alternative method for KSA. In anaerobic digestion (AD), the dual characteristics of natural zeolite like Mordenite will increase the CH 4 production of organic fraction of municipal solid waste (OFMSW). Further investigations are recommended to study the technical, economical, and environmental feasibility of natural zeolite utilization in WTE technologies in KSA.

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Section: Bet Surface Area Pore Size and Volume Of Natural Zeolitesmentioning

confidence: 92%

The potential of Saudi Arabian natural zeolites in energy recovery technologies

Nizami

Ouda

Rehan

et al. 2016

Energy

111

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“…ACL-A was used by treatment with ammonium chloride. De-aluminated sorbents were washed with boiling water and dried at 105°C (consist of NH 4 + cations) (Grejtak et al., 1992).…”

Section: Methodsmentioning

confidence: 99%

“…ACL-A was used by treatment with ammonium chloride. De-aluminated sorbents were washed with boiling water and dried at 105 C (consist of NH 4 þ cations) (Grejtak et al, 1992). NCL, ACL-H, and ACL-A were characterized by FT-IR (Perkin Elmer 460 Spectrum BXI spectrometer), Brunauer-Emmett-Teller (BET) surface area (Micromeritics Gemini 2360), scanning electron microscope (SEM) (LEO 1430VP), Zeta potential (MALVERN Nano-Z), X-ray diffraction (XRD) (Rigaku D-max 2200), and XRF methods (RIGAKU/ ZSX PRIMUS 2).…”

Section: Acid and Thermal Modification Of Clinoptilolitementioning

confidence: 99%

Adsorption of chlorophenolic compounds on activated clinoptilolite

Uçar

2019

Adsorption Science & Technology

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Nowadays, phenol and chlorophenols give rise to many organic pollutants. Concurrently, the occurring of phenolic compounds in aquatic ambit creates potential human health and environmental problems. There are a lot of technologies available for the treatment of organic pollutants. To remove phenol and chlorophenols, adsorption is a wastewater purification method. In this study, natural and activated clinoptilolite were carried out for the removal of phenol, orthochlorophenol, para-chlorophenol, and meta-chlorophenol. Activated clinoptilolite was prepared via acid activation and evaluated by means of Fourier transform infrared, scanning electron microscope, X-ray diffraction, X-ray fluorescence, and Brunauer-Emmett-Teller analysis. Phenol and chlorophenols have high adsorption rate, and equilibrium was reached in approximately 30 min. The maximum adsorptions of phenol, ortho-chlorophenol, meta-chlorophenol, and para-chlorophenols on the activated clinoptilolite were 6.7386, 8.6300, 9.5787, and 7.3758 mg g À1 , respectively. The affinity order was in the following order: m-CP > o-CP > p-CP > Ph. The adsorption of phenol and chlorophenols decreased after pH ¼ 6.25. Using the thermodynamic data, Gibbs free energy of the activated clinoptilolite was evaluated. The effects of different conditions such as pH, adsorption time, and initial concentration were analyzed. The adsorption rates of phenol and chlorophenols were constituted to be the maximum at approximately pH 6.5. Desorption of phenol and chlorophenols was carried out using ethyl alcohol solution (30%, v/v). The adsorption isotherms of phenol and chlorophenols on activated clinoptilolite were evaluated. The equilibrium adsorption data were the best suited to Freundlich adsorption isotherm pattern.

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