• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.357-366
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• 2003

This study was conducted to develop n convenient and efficient granular type absorbent with high CEC from powdery zeolite, which is a waste produced while crushing the natural zeolite of Korea to get a particular particle size. The change of mineralogical characteristics during hydrothermal alternation of natural zeolite to Na-P zeolite in alkaline solution at various reaction times was determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and total elemental analysis. The columnar aggregate of Na-P Zeolite was produced by calcinating the natural zeolite-charcoal extrudates of about 3 mm diameter. In 24 hours reaction, clinoptillonite, mordenite and feldspar in natural zeolite were disappeared by 3 N NaOH treatment, while Na-P Zeolite with spherical granular structure was newly detected by XRD. As increasing reaction time, Si/Al ratio in remaining solution was deceased. The CEC of the synthesized material increased more than 2 times compared with that of natural zeolite, although the diameter of Na-P zeolite were rather increased.

• Journal of the Korean institute of surface engineering
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• v.26 no.6
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• pp.334-340
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• 1993

The physico-chemical properties and characteristics after thermal treatment of natural zeolite from Kampo area were studied. The physico-chemical properties of natural zeolite were studied by investigating chemical composition, x-ray diffraction pattern(XRD), scanning electronic microscope(SEM), infrared spec-tra(IR), thermal analysis(TA), and cation exchange capacity(C.E.C.), and the characteristics of natural zeo-lite after thermal treatment from $400^{\circ}C$ to $900^{\circ}C$ were compared with the natural zeolite. This study showed that clinoptilolite was the predominant costituent in natural zeolite, and the natural zeolite contained a little amount of quartz and feldspar as impurities. Zeolite mineral was seen to develop slowly by the natural alternation of volcanic ash considering the almost amorphous crystal structure. The more temperature of ther-mal treatment increased, the more adsorption capacity decreased, considering the fact that the hydroxy peak diminished on infrared spectra, and that cation exchange capacity also decreased distinctly.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.43-47
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• 1998

This study was performed to remove the dissolved benzene in water by using TMA-Zeolite complex which was formed by the adsorption of TMA(Tetramethyl ammonium), a kind of ration surfactant on a natural zeolite produced in Korea. The dorminant clay minerals of the natural zeolite was identified by X-ray diffractometry and Infrared spectrophotometry to be mordenite and clinoptilolite. The CEC of the zeolite used was 95.9 cmol/kg. TMA was adsorbed on natural zeolite very quickly, and the amount of TMA adsorption on zeolite was known to be equivalent to about 8% of the CEC of natrual zeolite. The amount of benzene adsorption on TMA-zeolite complex was much more than natural zeolite, indicating that the dissolved benzene in water could be removed effectively by TMA-zeolite comple.

• Korean Membrane Journal
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• v.2 no.1
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• pp.48-55
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• 2000

In order to improve organic vapor separation efficiency of polydimethylsiloxane (PDMS) membrane, various zeolites (zeolite 4A, zeolite 13X and natural zeolite) were introduced into a thin PDMS film. The measurements of permeability and selectivity of zeolite-filled PDMS membranes were carried out with a CO$_2$gas and a CO$_2$gas/acetic acid vapor mixture, respectively. The CO$_2$permeability of zeolite-filled membranes decreased with increasing zeolite content and then recovered up to 30 wt% content. The effect of zeolite type on the improvement of CO$_2$permeability was found to be in the order of zeolite 13X > natural zeolite > 4A. The CO$_2$selectivity of zeolite-filled membranes was enhanced up to 9 times compared with the selectivity of a pure (unfilled) PDMS membrane. The effect of zeolite type on the improvement of CO$_2$selectivity was found to be in the order of natural zeolite > zeolite 13X > zeolite 4A.

• Korean Journal of Environmental Agriculture
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• v.10 no.1
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• pp.11-19
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• 1991

This study was carried out to develop the low-priced adsorbent by synthesizing the zeolite of high CEC with the natural zeolite and examining the ability of this zeolite to adsorb heavy metals. The dominant clay minerals were clinoptilolite and mordenite in natural zeolite, while phillipsite in the synthesized zeolite. Adsorption reaction of Cu and Zn on clays were reached to equilibrium after 1 hr. The amount of adsorption was increased as the concentrations of heavy metals or the initial pH of suspension was increased. The synthesized zeolite adsorbed heavy metals about twice as much as the natural zeolite. The adsorption of heavy metals on the synthesized zeolite was less affected by the initial pH of suspension than that on natural zeolite. At cumulative adsorption, the synthesized zeolite adsorbed much more heavy metals at early three treatments than the natural zeolite did. The amount of desorption by chloride salts was increased as the concentration of chloride salts was increased. The ability of salt to desorb was in the order of NaCl>$CaC1_2$>$AlC1_3$. It is estimated that the ability of the synthesized zeolite to remove heavy metals was better than that of the natural zeolite.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.643-648
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• 2000

The purpose of this study is to remove the ammonia by using the ion exchange effect of natural zeolite (clinoptilolite in this system) and artificial zeolite and remove the organic material by using the Absorbent Biofilter. On the removal of ammonia, natural zeolite is the more effective than artificial zeolite But on the simultaneous removal of ammonia and phosphorus, artificial zeolite is the more effective than natural zeolite.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.750-757
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• 2009

The ammonium ion exchange characteristics of natural zeolite were investigated to remove ${NH_4}^+-N$. The effect of water temperature, particle size and competitive cation on the exchange capacity was examined. Ammonium ion exchange capacity tended to decrease when the temperature increased from $25^{\circ}C$ to $40^{\circ}C$. Exchange capacity was increased according to the particle size of natural zeolite comes to be small. Batch isotherm experiments were conducted for measuring ammonium ion exchange capacity. The ion exchange capacity was well described either by the Langmuir isotherm model or by the Freundlich isotherm model. The ammonium ion exchange capacity ($q_m$) of zeolite carrier can be calculated $11.744mg-{NH_4}^+/g$-carrier. The ion exchange capacity of manufactured zeolite carrier was showed a similar tendency as ion exchange capacity of powder-sized natural zeolite. Therefore, zeolite carrier can be used for increasing of nitrogen removal efficiency in the wastewater treatment plants.

• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.42-53
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• 1999

A study on the synthesis of zeolite from coal fly ash from power plant was carried out to reduce environmental problems and reuse industrial waste. The synthesized zeolite was proved to be Zeolite 4A type by means of the XRD and SEM analysis, and then the synthesized zeolite was used as an absorbent to remove the $NH_4^+$ ions in the wastewater and water. In the ion exchange of single $NH_4^+$ ions by the natural zeolite and the synthesized zeolite, the ion exchange reached equilibrium within 10 min. and 1hr, respectively. The amount of ion exchanged $NH_4^+$ to the unit weight of natural zeolite and zeolite 4A were 1.09 and 3.54 meq/g respectively, and the amount of $NH_4$ ion exchanged by the synthesized zeolite was higher than by the natural zeolite. The ion exchange kinetics fitted very well to the Feundlich and Langmuir isotherm. The effects of coexisting cations on the ion-exchange properties of zeolites were studied in order to apply them to water treatment. In the bisolute-system of the $NH_4^+-K^+$ and $NH_4^+-Na^+$ systems, the ion exchange capacity was smaller than the single $NH_4^+$ ion system. The effects of coexisting cations on the ion exchange system by the natural zeolite and the synthesized zeolite were found to be $K^+>Na^+$ and $Na^+>K^+>>Mg^{2+}>Ca^{2+}$, respectively.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2003.10a
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• pp.122-128
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• 2003

To develop a Mg-Zeolite for simultaneous recovery of the N and the P from sewage water, the natural zeolite was treated with 20% $MgCl_2$ solution by changing the pH the temperature and the treating time of the solution. And the contents of Ca Fe Na K Mg of Mg-Zeolite were analyzed by ICP. The optimum treatment condition for Mg-Zeolite was induced to pH 7.0 $50^{\circ}C$ in 20% $MgCl_2$ solution and for 80min treatment. And the Na and the K ions in natural zeolite are significant factors for Mg exchange in the zeolite.

• Computers and Concrete
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• v.22 no.5
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• pp.449-459
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• 2018

Concrete is one of the most widely used construction materials in the world. Producing economical and durable concrete is possible by employing pozzolanic materials. The aim of this study is to underline the possibility of the utilization of natural zeolite in producing concrete and investigate its effects basically on the strength and durability of concrete. In the production of concrete mixes, Portland cement was replaced by the natural zeolite at ratios of 0%, 10%, 15%, and 20% by weight. Concretes were produced with total binder contents of $300kg/m^3$ and $400kg/m^3$, but with a constant water to cement ratio of 0.60. In addition to compressive and flexural strength measurements, freeze-thaw and high temperature resistance measurements, rapid chloride permeability, and capillary water absorption tests were performed on the concrete mixes. Compared to the rest mixes, concrete mixes containing 10% zeolite yielded in with the highest compressive and flexural strengths. The rapid chloride permeability and the capillary measurements were decreased as the natural zeolite replacement was increased. Freeze-thaw resistance also improved significantly as the replacement ratio of zeolite was increased. Under the effect of elevated temperature, natural zeolite incorporated concretes with lower binder content yielded higher compressive strength. However, the compressive strengths of concretes with higher binder content after elevated temperature effect were found to be lower than the reference concrete.