• Journal of the Korean Applied Science and Technology
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• v.16 no.2
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• pp.117-125
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• 1999

The alkylation benzene with 1-dodecene of Mordenite, Zeolite ${\beta}$ and Zeolite Y was studied in the stirring batch reactor. The kinds of zeolites were found to have influenced the reaction conversion and distribution of phenyldodecane isomer in the product. Compared to the alkylation conducted over Zeolite Y and Zeolite ${\beta}$, the alkylation over Mordenite exhibited higher distribution of 2-phenyldodecane and the alkylation conducted over Zeolite Y and Mordenite, the alkylation over Zeolite ${\beta}$ exhibited higher distribution of heavy alkylate which formed through oligomerization reaction readily deactivated the Lewis acid sites. A special feature of the effect of the benzene to 1-dodecene ratio the reaction conversion and selectivity of phenyldodecane isomer was found. At alkylation of benzene with 1-dodecene over Zeolite ${\beta}$, when the catalyst content in the system was high, the reaction will reach the optimal conversion at the higher B/D. When the benzene to 1-dodecene ratio was high, the selectivity of phenyldodecane isomer is high. It was also found that at the similar reaction conversion there was the same product distribution regardless of D/C ratio.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1463-1468
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• 2012

The purpose of this work is to study the desorption characteristics of water vapor on zeolites saturated with water vapor. Three kinds of zeolite; zeolite 3A, zeolite 4A, and zeolite 5A were used as adsorbent. The desorption experiments with several different temperatures in the range of $90{\sim}150^{\circ}C$ and several different flow rates in the ranges of 0~0.4 L/min on zeolite bed were carried out. The desorption ability of water vapor was most effective on zeolite 5A among the compared zeolites. The higher the desorption temperature of water vapor was, the faster the desorption velocity was. The desorption ability of water vapor with an air supply was higher than that without an air supply. The most appropriate air flow rate was considered as 0.1 L/min.

• Environmental Engineering Research
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• v.25 no.4
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• pp.554-560
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• 2020

This study focuses on nitrification through a biological aerated filter (BAF) that is filled with a zeolite medium at low concentrations of ammonia. The zeolite medium consists of natural zeolite powder. The BAF is operated under two types of media, which are a ball-type zeolite medium and expanded poly propylene (EPP) medium. Nitrification occurred in the zeolite BAF (ZBAF) when the influent concentration of ammonia nitrogen was 3 mg L-1, but the BAF that was filled with an EPP medium did not experience nitrification. The ammonia nitrogen removal efficiency of ZBAF was 63.38% and the average nitrate nitrogen concentration was 1.746 mg/L. The ZBAF was tested again after a comparison experiment to treat pond water, and municipal wastewater mixed pond water. The ZBAF showed remarkable ammonia-nitrogen treatment at low concentration and low temperature. During this period, the average ammonia nitrogen removal efficiency was 64.56%. Especially, when water temperature decreased to 4.7℃, ammonia nitrogen removal efficiency remained 79%. On the other hand, the chemical-oxygen demand (COD) and phosphorus-removal trends were different. The COD and phosphorus did not show as efficient treatment as the ammonia-nitrogen treatment.

• Journal of the Korean Applied Science and Technology
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• v.16 no.3
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• pp.217-221
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• 1999

This study was carried out to synthesis the zeolite using the bituminous coal fly ash emitted from power plant that occurs several environmental problems. In spite of fly ash has contained high content of $SiO_2$ and $Al_2O_3$, it disposed mainly landfill. If the effective methods to recover the $SiO_2$ and $Al_2O_3$ were developed, the fly ash could be utilized valuable raw materials. In this study, fly ash was used as raw material to synthesize the zeolite by pressurized hydrothermal reaction. Also, experimental parameters included temperature($70{\sim}110^{\circ}C$, and pressure($140{\sim}200$ psi) of crystallization were investigated. The more crystallization pressure was increased, the more Zeolite 4A was synthesized at 70 and $90^{\circ}C$. Zeolite 4A of metastable phase tend to be transformed into sodalite of stable phase at $110^{\circ}C$.

• KSBB Journal
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• v.18 no.6
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• pp.506-510
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• 2003

The artificial sewage was treated using a horizontal flow zeolite-filled reed bed. The artificial sewage was fed into the reed bed for 10 minutes every 6 hours at the hydraulic load of 314 L/㎡$.$day. The filtering height of the reed bed was 100 cm and the zeolite mixture was filled in the reed bed. The mixttjre consisted of the same volume of two types of zeolite: 0.5∼l mm and 1∼3 mm in diameter. Annual average removal efficiency was CODcr 95.8%, T-N 56.5％, NH$\_$4/$\^$＋/-N 99.4％ and T-P 61.3%. T-N removal efficiency decreased remarkably from 84 to 32％ with the operating time.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.215-220
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• 1989

For development of slow releaseing K-fertilizer using natural zeolite, two kinds of K adsorbed zeolite were made by ion exchange reaction in $K^+$ saturated aqueous solution. K-Zeolite was prepared by removing the excess salt after K adsorption on zeolite, however, NW. K-Zeolite was prepared only by K adsorption reaction without removing the excess salt. The adsorbed K on zeolite was not easily released, but continuously and slowly released from the surface of zeolite. By the results of application for tobacco cultivation, the K contents in soil treated with K-Zeolite and NW. K-Zeolite were lower than that of control (20kg/10a) at the early growth stage, but were higher at the late growth stage. Therefore, the results suggest that K adsorbed zeolite could be applied as a slow-releasing K fertilizer.

• Journal of Environmental Science International
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• v.13 no.7
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• pp.661-665
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• 2004

As the concentration of ammonium nitrogen could be reached 2～3 mg/L in the winter in the river. It was clear that the excessive concentration of chlorinated organics could be produced with the increase of chlorine addition to remove ammonium nitrogen. In the innovative ammonium nitrogen removal process, zeolite adsorption is very efficient as substitute for rapid sand filtration without other adverse quality change in the water. This study is conducted to evaluate the feasibility of ammonium nitrogen removal and regeneration by zeolite adsorption in drinking water treatment. Also, the reuse possibility of zeolite is evaluated to change the removal efficiency of ammonium nitrogen through several times of regeneration. The ammonium nitrogen was not removed in sand filter, but it was almost removed in zeolite filter during 7 days. The sand and zeolite filters have a similar result of turbidity removal. Therefore, zeolite filtration was confirmed the removal of turbidity and ammonium nitrogen as a media. When compared KCl with NaCl as a chemical for zeolite regeneration, it is demonstrated that KCl was more efficient than NaCl in the ability of zeolite regeneration. The adsorption rate of ammonium nitrogen was almost not decreased in the results of several times of regeneration. It is indicated that both zeolite and regeneration solution were possible to reuse without variation of regeneration rate through this study.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1321-1327
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• 2003

Two different kinds of cases, with and without addition of noncrystalline silica to the Hadong kaolin were studied to obtain useful information on the synthesis of zeolite. The research was carried out to investigate the formation area and the crystalized degree of zeolite according to a synthetic time, the water content of raw material mixture, KOH concentration, and stirring intensity. In the case of without addition of noncrystalline silica to the Hadong kaolin and the low concentration range of KOH, the structure of the kaolin was not changed. However, when the mole ratio of K2O/SiO$_2$ in natural kaolin was increased, Linde-L zeolite and unknown structure of kaolins, U-1 and U-2 were produced. While in the high concentration range of KOH, the unknown structure of kaolins, U-6 and U-2, were produced and the production rate of U-6 was increased with the increased of K2O/SiO$_2$ mole ratio. In the case of with addition of noncrystalline silica to the Hadong kaolin and treatment with KOH hydrothermal processing, ZSM-5, ZSM-35, and Linde-L zeolites and the mixture of unknown structure of zeolites, U-1, U-2, U-3, and U-4, were obtained. Both cases demonstrated that the synthesis of zeolite from the Hadong kaolin was highly influenced by KOH concentration of raw material mixture.

• Journal of Applied Biological Chemistry
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• v.42 no.1
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• pp.25-28
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• 1999

For investigating the effectiveness of Korean natural zeolite for removal of $NH_4{^+}$ in waste waters containing $NH_4{^+}$ and $Cu^{2+}$, the adsorption of $NH_4{^+}$ and $Cu^{2+}$ by three Korean natural zeolite samples, which contained mordenite and/or clinoptilolite, was measured by adding solutions containing $NH_4{^+}$ and $Cu^{2+}$ or both at a concentration range from 1 to 7 mmol(+)/L of each cation. In the solutions, the zeolite samples adsorbed more amounts of $NH_4{^+}$ than $Cu^{2+}$. By seven successive equilibrations, Korean natural zeolites adsorbed $NH_4{^+}$ corresponding to 23~33% of those cation exchange capacity from the solution containing both $NH_4{^+}$ and $Cu^{2+}$ at 3 mmol(+)/L of each cation. Whereas, the corresponding adsorption of $Cu^{2+}$ was 17-27% of the CEC. Korean natural zeolite exhibited selectivity for $NH_4{^+}$ but not for $Cu^{2+}$. Nevertheless, it using as a soil amendment after removing of $NH_4{^+}$ in waste waters should be carefully controlled on the application rate.

• Macromolecular Research
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• v.12 no.5
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• pp.443-450
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• 2004

We have studied the effects that inorganic zeolite powder have on structurally different copolymer [poly(propylene-co-ethylene)] and terpolymer [poly(propylene-co-ethylene-co-l-butene)] systems and the possibility of preparing suitable porous composite films. The impact strength and yield stress of the composites did not improve upon any further loading of zeolite, but the modulus increased gradually with respect to the filler loading. The experimental modulus of each of the two systems was compared with theoretical models. We performed a morphological study of the filler mixing efficiency and image analysis. The number-, weight-, and z-average air hole diameters were compared with respect to the draw ratio as well as the zeolite loading. The experimental results suggest that these two matrices can provide a new choice for preparing future multiphase polymeric porous films by stretching them unidirectionally. In particular, we suggest that a 40 wt% zeolite loading at a draw ratio of 4 is useful for porous film applications.