Ion exchanges in clinoptilolite.

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University of Salford , Salford
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The three zeolites examined (clinoptilolite, mordenite and ferrierite) were prepared in both the sodium and ammonium forms before exchange with lead was attempted. The selectivity of these materials for lead was measured in terms of experimental ion-exchange isotherms at a temperature of by: The process of ion exchange occurs between the A ZA cation in solution and B ZB* cation in the zeolite, and can be formulated as follows: Z B A ZA + Z A B ZB* ↔ Z B A ZA* + Z A B ZB.

where Z A and Z B show the valences of the cations, and A ZB* and B ZB* show the cations in the zeolite : Tevfik Ünaldı, Selahattin Kadir.

Natural clinoptilolite (Cpt: O 2 •H 2 O) from Castle Creek, Idaho, and its cation-exchanged variants (Na-Cpt, NaK-Cpt. Nak-Cpt. and Ca-Cpt) were studied by high-temperature calorimetry.

The hydration enthalpy for all the clinoptilolites is about - 30 kJ/mol H 2 O (liquid water reference state) at 25 °C. The energetic stabilization effect of hydration on each clinoptilolite can be Cited by: Abstract The two‐dimensional channel structure of clinoptilolite has been altered systematically by ion exchange to study the effects of cation type, size, location, and distribution on the diffusi Cited by: The ion-exchange and reduction processes for Cu2+ ions in clinoptilolite from the Caimanes deposit (Moa, Cuba) were studied at different temperatures.

The ion-exchange studies were done to determine the kinetic parameters of Cu2+ removal from. The obtained results indicate that the rate of exchange of lead ions Ion exchanges in clinoptilolite. book the H-form of clinoptilolite is controlled by internal diffusion mechanism of the process. The effective diffusion coefficient depends linearly on the radius of the incoming ion and does not depend on the concentration of external solution.

Abstract: In order to combine the microbial metabolism characteristics in biological aerated filter (BAF) with the adsorption and ion-exchange ability of natural clinoptilolite to treat sanitary wastewater, the experiment use clinoptilolite powder as main materials to prepare the large specific surface and high porosity spherical compound.

Ion exchange removal of ammonium by clinoptilolite-Na is shown in eqn [24 ], where Z– is clinoptilolite framework, bold font is used to show exchangeable ion and zeolite framework, electrostatic interactions are shown as ‘:’, and aqueous species are shown in plain font.

[24]Z–:Na++NH4+=Z–:NH4++Na+. widening the range of ion-exchange materials. The results of the study of structural, physicochemical and ion-exchange properties of natural alumosilicates allow developing the theoretical bases for the directed alternation of the complex of useful properties of natural minerals, meeting the main criteria required for sorption materials.

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User Name: Password: Guest User: Company. Ion-exchange is the most commonly employed in industrial water treatment, among the water purification technologies [2]. Ion-exchange is a process whereby a solid substance (the ion-exchanger) and some aqueous solution exchange ions [3].

Clinoptilolite has been widely exploited as solid substance for Na. Get this from a library. Ion-exchange of clinoptilolite-rich rocks in Argo drain water at Idaho Springs, Colorado, and related experimental aspects.

[George A Desborough; Geological Survey (U.S.)]. Phillipsite has one of the highest known ion-exchange capacities among natural zeolites. It reaches the value of 5 meqg −1, whereas the one of a natural clinoptilolite is meqg−1, the highest ion-exchange capacity has been found at the synthetic zeolite A ( meq g −1).

@misc{etde_, title = {Ion exchange properties of clinoptilolite; Ionoobmennie svoystva klinoptilolita} author = {Bogatirev, V.

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L., and Kramarenko, L. D.} abstractNote = {Physicochemical and sorption properties of clinoptilolite are studied. Kinetics of ion exchange for system R H-Cu{sup 2+} is studied. Sorption of copper and iron from their mixed solutions in wide range of component.

Description Ion exchanges in clinoptilolite. PDF

Mačala and Pandová () have noticed that the clinoptilolite modified by ion exchange and thermally could be used for reducing the nitrogen monoxide in the noxious gases evolved by the combustion engines, by adsorption. In addition to that, the adsorption capacity increases significantly by chemical treatment since the clinoptilolite exchanged with ammonium chloride and cobalt chloride show o high ability in decreasing the nitrogen monoxide.

In the present study natural and Na-rich form of clinoptilolite are examined, in respect to ion exchange of Pb 2+, Cu 2+, Cr 3+, and Fe 3+. Equilibrium and kinetic. Solid‐State Ion Exchange with Salts of Noble Metals; Miscellaneous; Some Considerations on Thermodynamic and Kinetic Aspects of SSIE Effect of Temperature and Salt Concentration in Salt/Zeolite Mixtures; The Role of Water in Solid‐State Ion Exchange; Kinetics of Solid‐State Ion Exchange.

The ion exchange on natural zeolites – clinoptilolites is characterized by a number of specific features, particularly, two-stage particle diffusion kinetics. The possibilities for using available solutions of sorption dynamics for modeling and calculation of the ion-exchange processes on.

Clinoptilolite-Na – heulandite-Na solid solution series Use of clinoptilolite in industry and academia focuses on its ion exchange properties having a strong exchange affinity for ammonium (N H 4+).

A typical example of this is in its use as an enzyme -based urea sensor. Abstract. To provide a thermodynamic basis for understanding zeolite-water interactions in geologic systems, ion-exchange experiments were conducted at 25°C between clinoptilolite, which is the predominant zeolite mineral in altered pyroclastic and volcaniclastic rocks and aqueous mixtures of Na + /K + and Na + /Ca 2+.Isotherm points were obtained by equilibrating Na-clinoptilolite, which was.

generation consisted of ion exchange followed by oxidation of the liberated ammonium. As soon as clinoptilolite containing a large amount of ammonium ions is placed in a salt solution, ion exchange takes place according to Equation 1.

Z-NH4+ + Na. A natural clinoptilolite-rich zeolite (from St. Cloud Mine near Winston, NM, USA) with a size of mesh ( mm) was used in this study. Detailed information on the mineral composition, cation exchange capacity, and surface area of the zeolite can be found in previous studies [19, 20].

clinoptilolite structural model of Koyama and Takeuchi [7] (ICSD #) was used. Results Powder XRD and EDS Data of Ba Exchanged Clinoptilolite The clinoptilolite sample subjected to ion exchange with barium cations for a period up to the 22 days (at RT and 90 C) undergoes exchange, which proceeds all the time with di erent speed.

Over the past four decades, notable advancements in the theory and application of ion exchange science uncovered a wealth of knowledge that fueled new scientific pursuits and created synergies with myriad scientific endeavors.

Today, pioneers continue to break new ground by synthesizing novel materials and merging the interdisciplinary fields of sc. In the present study ion exchange of Pb2+, Cu2+, Fe3+ and Cr3+ on natural clinoptilolite is examined at 27±1°C and initial concentration of 10 meq/dm3.

Equilibrium is favorable for Pb2+, unfavorable for Cu2+ and sigmoid for Cr3+ and Fe3+. Get this from a library. Optimization of ammonia removal by ion exchange using clinoptilolite. [John H Koon; Warren J Kaufman; University of California, Berkeley. Sanitary Engineering Research Laboratory.; University of California, Berkeley.

School of Public Health.; United States. Environmental Protection Agency.] -- The zeolite ion exchanger clinoptilolite was investigated with the objective.

Throughout the s there was a decline in the number of fundamental studies carried out on the ion exchange properties of zeolites and related materials. () Reduction of caesium and cobalt activity in liquid radwaste processing using clinoptilolite zeolite at Duke power company.

Proceedings of the Buy this book on publisher's site. Zeolites are porous minerals with high absorbency and ion-exchange capacity. Their molecular structure is a dense network of AlO4 and SiO4 that generates cavities where water and other polar molecules or ions are inserted/exchanged.

Even though there are several synthetic or natural occurring species of zeolites, the most widespread and studied is the naturally occurring zeolite clinoptilolite.

Natural clinoptilolite (Cpt: Na K Ca Mg Al Si O 2 H 2 O) from Castle Creek, Idaho, and its cation-exchanged variants (Na-Cpt, NaK-Cpt, K-Cpt, and Ca-Cpt) were studied by high-temperature calorimetry.

The hydration enthalpy for all the clinoptilolites is about −30 kJ/mol H 2 O (liquid water reference state) at 25 °C. The energetic stabilization. each cation-exchange treatment, the Cp sample was washed with distilled water to eliminate soluble impurities and subsequently dried at room temperature.

Then, 1 g of the sample was placed in a cm diameter glass ion-exchange column of 12 cm length and held at 20 ºC. Subsequently, m of solution was percolated through the sample for h.

Ion-exchange Clinoptilolite from Beli plast deposit, Kardzhali, Bulgaria, was used for this study. For three months a set of single crystals with average size between and mm was treated in an aqueous NaCl solution (1 M) in a Teflon reactor with temperature.Thermodynamic calculations of ion-exchange reactions were applied for clinoptilolite in a natural state and after irradiation with three doses of β-radiation (10 12, 10 15, 3 × 10 16 e/cm 2) and γ-radiation (70 Mrad).Samples were equilibrated with binary systems of K + ↔ Na + and Cs + ↔ Na + at 25° and a total normality of ivity for K was not affected after γ-radiation.Forward and reverse ion-exchange isotherms for the binary sodium-ammonium, potassium-ammonium, and calcium-ammonium systems on clinoptilolite have been measured in aqueous solutions at a total concentration of equiv/dm{sup 3} and at K.

Prior to exchange experiments it was attempted to prepare homoionic forms of the zeolite by exhaustive.