• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.258-261
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• 2006

The addition of zeolite particles enhances the stability of mRNA molecules in a cell-free protein synthesis system. When $20{\mu}g/{\mu}L$ of zeolite (Y5.4) is added to a reaction mixture of cell-free protein synthesis, a substantial increase in protein synthesis is observed. The stabilizing effect of zeolite is most dearly observed in an in vitro translation reaction directed by purified mRNA, as opposed to a coupled transcription and translation reaction. Upon the addition of zeolite in the in vitro translation reaction, the life span of the mRNA molecules is substantially extended, leading to an 80% increase in protein synthesis. The effect of zeolite upon the mRNA stability appears be strongly related to the cation exchange (potassium to sodium) reaction. Our results demonstrate the possibility of modifying this biological process using heterogeneous, non-biological substances in a cell-free protein synthesis system.

• 환경위생공학
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• 제12권1호
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• pp.49-58
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• 1997

A study on the synthesis of zeolite from bituminous coal ESP fly ash as a raw material, which was emitted from the power plant, was carried out to reduce environmental problems and reuse of the industrial wastes. Bituminous coal fly ash was used as the source of silica and alumina. Zeolite was synthesized by hydrothermal reaction in aqueous NaOH solution with sodium aluminate as additive. The objective of this study is to elucidate the effect of several experimental variables on the synthesis of zeolite. The effects of preroasting temperature, mixing speed, leaching alkalinity, and molar ratio of Na$_{2}$O/SiO$_{2}$ and SiO$_{2}$/Al$_{2}$O of the products were investigated. The synthesized zeolite was proved to be NaA, which is known as 4A type, by comparing with SEM images, and X-ray diffraction analysis. And also we know that the transformation of zeolite A take places into other types of zeolites, i.e. Hydroxysodalite, zeolite P, with the variation of leaching alkalinity.

• 한국환경보건학회지
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• 제33권4호
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• pp.317-324
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• 2007

The sewage treatment sludge disposal has become a serious environmental problem because of restricted direct land-filling and oceandumping in spite of their large amounts discharged. So the recycling of sewage treatment sludge is very useful alternative for waste management. Here, we studied the feasibility of zeolite synthesis in open system from the sewage treatment sludge incinerator fly ash by means of hydrothermal synthesis. We considered the concentration of NaOH, reaction time, reaction temperature and reaction step as synthesis variables. The phase of zeolite products was identified by X-ray diffractometer(XRD) and ammonium ion exchange test was performed for the raw fly ash and two zeolite products(Z-3 and Z-5). In leaching test of the raw fly ash, hazard metal is detected very low level compared with regulatory leaching test standard. But in total recoverable test, the total contents of the fly ash were very high in terms of the standard for waste-derived fertilizer. Through hydrothermal reaction, small amount of zeolite P was synthesied in 1 N of NaOH solution and relatively large amount of hydroxysodalite was synthesied in 3 N and 5 N of NaOH solution with similar peak intensity. Addition of an aging step in the synthesis didn't increase the amount of zeolite phase. Maximum $NE_4^+-N$ exchange capacity is 1.49 mg $NH_4^+-N/g$ in Z-3 and 1.38 mg $NH_4^+-N/g$ in Z-5. Most of the ammonium ion is exchanged in 30 minutes and disorption did not occur until 5 hours.

• 공업화학
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• 제28권3호
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• pp.286-289
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• 2017

통계적 실험계획법을 이용하여 나노입자 합성 공정의 최적화 방법론을 제시하기 위하여 대상 물질로 제올라이트 4A의 합성을 수행하였다. 실리콘 전구체인 sodium metasilicate (SMS)의 농도를 조절하여 합성한 제올라이트 4A를 XRD, SEM 및 질소흡착법으로 특성분석 하였다. 특히 XRD 분석으로 결정한 결정도로 제올라이트 4A의 합성결과를 판단할 수 있었다. 실험계획법 중 일반요인분석을 이용하여 반응장치, 반응온도 및 반응시간에 따른 주효과도 및 교호작용을 분석하였다. 또한 반응표면분석법을 통하여 결정도 최대치를 가지는 제올라이트 4A를 합성할 수 있는 최적의 조건으로 계산하였다. 구체적으로는 autoclave를 사용하고 반응시간 3 h 및 반응온도 $110^{\circ}C$의 반응조건이 제시되었다. 더욱이 실리콘 전구체로 Ludox를 사용하는 조건하에서, 다양한 결정화도를 가지는 제올라이트 4A에 대한 최적의 합성조건을 모든 범위에서 대하여 표면도와 등고선도를 이용하여 제시하였다.

• 청정기술
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• 제24권1호
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• pp.21-26
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• 2018

석탄은 오랜 전부터 사용해온 유용한 산업 자원이다. 그러나 채굴과정에서 많은 폐기물인 석탄 폐석이 발생된다. 석탄 폐석은 주변 환경오염의 주범이며, 그 양 또한 수억 톤이 적치된 상태이다. 이러한 석탄 폐석에 포함된 성분 중 상당량이 $SiO_2$와 $Al_2O_3$ 성분이고 이것은 여러 산업에서 유용하게 사용되는 제올라이트의 주원료이기도 하다. 본 연구는 석탄 폐석을 이용하여 제올라이트를 합성하고, 상용 제올라이트와의 물성 및 흡착 성능을 비교한 것이다. 합성제올라이트는 상용 제올라이트와 유사한 물성을 보여주고 있으며, 대기 환경오염 유발가스($CO_2$, Toluene, $SO_2$, 등)에 대한 흡착성능 또한 우수하였다.

• 한국세라믹학회지
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• 제20권3호
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• pp.255-259
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• 1983

Am(rphous aluminosilicate zeolite A and hydroxysodalite were obtained by reaction of Hadong kaolin(halloysite) with IN sodium hydroxide solntion in the temperature range of 60 to 10$0^{\circ}C$ For determination of the mechanism of the reaction Various possible mechanisms were compared with the experimental results. It was observed that the reaction mechamism of zeolite A synthesis from Hadong kaolin was first order consecu-tive reaction as follows : halloysitelongrightarrowamorphous aluminosilicatelongrightarrowzeolite Alongrightarrowhydroxysodalite

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.616-620
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• 2001

The objectives of this study are to investigate the suitability of various coal fly ashes and incineration ashes for zeolite synthesis. Zeolite P and hydroxysodalite are produced from coal fly ash and paper sludge incineration ash. When soluble and acid-soluble materials in incineration fly ash are removed by the water washing or acid washing before hydrothermal synthesis, hydroxysodalite can be produced. The factors to make solid-liquid separation difficult are the calcium component and the unburned carbon in ash.

• 대한환경공학회지
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• 제30권6호
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• pp.659-665
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• 2008

본 연구는 서울특별시 소재 S 물재생센터의 하수슬러지 소각로에서 발생하는 비산재를 이용한 제올라이트 합성에 관한 것이다. 이를 위해 출발물질로서 소각비산재의 특성, 제올라이트 합성을 위한 수열반응조건, 합성된 제올라이트의 적용성을 조사하였다. 하수슬러지 소각 비산재에는 중량으로 각각 42.8%와 21.2%로 많은 양의 SiO$_2$와 Al$_2$O$_3$를 함유하고 있어, 제올라이트 합성의 출발물질로 이용이 가능하였다. 소각 비산재의 중금속 유해성 파악을 위해 용출시험과 함유량 시험을 실시하였는데, 용출시험 결과는 폐기물관리법에서 규제하는 용출기준에 비해 매우 적은 양이 검출되었으나, 함유량 시험에서는 비료관리법 상의 보통 비료 중 유기질 비료 및 부산물 비료의 중금속 위해성 기준을 초과하였다. 수열반응 결과, 주로 생성된 제올라이트는 analcime과 zeolite P1이었다. Analcime은 teflon 반응용기에서 생성되었고, 최적의 반응조건은 알칼리(NaOH)용액의 농도 1 N, 합성온도 135$^{\circ}C$, 합성시간 16시간이었다. 한편, Zeolite P1은 붕규산 유리질 반응용기에서 합성되었고, 알칼리(NaOH)용액 농도 5 N, 합성온도 130$^{\circ}C$, 합성시간 16시간에서 가장 많은 양이 합성되었다. 수열반응 후의 유해 중금속 함유량은 합성전과 비교하여 analcime 생성물에서는 비슷한 수준으로, zeolite P1 생성물에서는 약 절반 정도 감소하였다. 합성된 제올라이트의 성능은 암모늄 이온의 교환정도로서 파악하였는데, 소각 비산재에서 0$\sim$1.0 mg NH$_4{^+}$/g, analcime합성물 3.0$\sim$7.4 mg NH$_4{^+}$/g, 그리고 zeolite P1합성물에서 14.6$\sim$17.8 mg NH$_4{^+}$/g이었다. 천연 제올라이트인 clinoptilolite와 phillipsite의 암모니아 제거능력이 15$\sim$35 mg NH$_4{^+}$/g 정도인데, 본 연구에서는 zeolite P1합성물이 이 범위를 충족하였다. 이러한 관점에서 하수슬러지 소각 비산재를 이용한 제올라이트 합성은 폐기물 재활용의 좋은 대안이 될 수 있을 것으로 판단된다.

• 한국환경과학회지
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• 제12권12호
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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.

• 한국표면공학회지
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• 제46권6호
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• pp.277-282
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• 2013

This study is an experimental attempt to confirm the binder effect of zeolite coating on glass plate by heat treatment. As a result, zeolite was successfully formed with low concentratios of pressure, whose concentration was effective in 10% or more for thin film zeolite coating. And as the content of the binder (TEOS) in mixed coating solution was higher, the zeolite was fastened better on the surface. Above 5% content of the binder in the coating solution, TEOS hindered zeolite synthesis of the precursor and brought to zeolite capacity decrease. Furthermore, when the concentration of the precursor, sedimentation rate of the precursor was higher and the coating efficiency is reduced thereby. Therefore, the most effective concentrations of the precursor and TEOS in the coating solution was 10% and 5%, respectively. It was concluded that zeolite coating is produced by heat treatment method after dipping without hydrothermal synthesis.