• 한국환경농학회지
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• 제28권4호
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• pp.386-391
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• 2009

The purpose of this study is to elucidate the adsorption properties of fly ash (FA)-derived zeolites A and X for the divalent cationic herbicides, paraquat and diquat. Their adsorption isotherms were well fitted to the Langmuir equation, indicating that adsorption mainly occurred on the crystal surface. FA-zeolite X showed a higher adsorption capacity than that of FA-zeolite A due to wide pore window size in spite of its low CEC. The equilibrium adsorption increased with increasing the reaction temperature because of the enhanced molecule activity and the thermal expansion of zeolite pore windows. Overall, these results demonstrated that the FA-zeolite synthesized from fly ash could be used as a low-cost mineral adsorbent for the removal of environmental cationic organic pollutants from the aqueous solution.

• Journal of Applied Biological Chemistry
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• 제42권1호
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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.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1542-1546
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• 2015

The purpose of this study was to investigate the potential of zeolite-supported sulfatereducing bacteria (SRB) in enhancing the removal of Cu²⁺, Ni²⁺, and Cr⁶⁺ in contaminated seawater. Our results show that SRB-immobilized zeolite carriers can enhance the removal of heavy metals. In addition, heavy metals were generally better removed at conditions of 37°C. Cu²⁺, Ni²⁺, and Cr⁶⁺ were effectively removed by 98.2%, 90.1%, and 99.8% at 100 parts per million concentration of the heavy metals, respectively. These results indicate that SRB-zeolite carriers hold great potential for use in the removal of cationic heavy metal species from marine environment.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.23-26
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• 2001

Batch test and column test were performed to develop the design factors for PRBs against the contaminated groundwater by ammonium and lead. Clinoptilolite, one of the natural zeolites having excellent cation exchange capacity(CEC), was chosen as the reactive material through the ion-exchange mechanism. In the batch test, the reactivity of Clinoptilolite to ammonium and lead was examined with varying the particle size of Clinoptilolite. The nit weight of Clinoptilolite showed removal efficiencies of 65 % against the ammonium and 98% against lead. The effect of particle size of Clinoptilolite was not noticeable. In the column test, the permeability was examined using flexible-wall permeameters with varying the particle size of Clinoptilolite. When the washed Clinoptilolite having the diameter of 0.42-0.85 nm was mixed with Jumunjin sands in 20:80 ratio (w/w), the highest permeability of 2$\times$10$^{-3}$ -7 x 10$^{-4}$ cm/s was achieved. The reactivity and the strength property of the mixed material were investigated using fixed wall column having 8 sampling ports on the wall and the direct shear test, respectively. Clinoptilolite was found to be a suitable material for PRBs against the contaminated groundwater with ammonium and/or heavy metals.

• 공업화학
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• 제7권1호
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• pp.43-50
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• 1996

Clinoptilolite 계열의 국내산 천연제올라이트에 대한 상규명과 암모늄 이온 제거능력에 대해 연구하였다. 영일만 지역에 매장되어 있는 국내산 천연제올라이트는 XRD와 FT-IR 분석에 의해 열적으로 불안정한 heulandite임이 증명되었다. 또한 $K^+$ 이온으로 이온교환된 heulandite가 가장 높은 열적 안정성을 보였다. 그러나 암모늄이온의 제거능력에 있어서는 이온교환하지 않은 제올라이트가 가장 우수한 제거능력을 보였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.435-442
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• 2000

Batch test and column test were performed to develop the design factors for permeable reactive barriers(PRBs) against ammonium and heavy metals, Clinoptilolite, a kind of natural zeolites having excellent cation exchange capacity(CEC), was choosen for the reacting materials through the ion-exchange mechanism. In the batch test, the reactivity of clinoptilolite for ammonium, lead, and copper was examined varying the initial concentration of contaminants(ammonium: 20, 40, 80 ppm, heavy metals: 10, 20, 40 ppm) and the particle size of clinoptilolites(0-0.15, 0.42-0.85, 1-1.25 mm). The reactivity is increasing as the initial concentration decrease and particle size decrease. In the column test, the permeability and the reactivity of the specimens were examined using flexible-wall permeameter. Specimens were made of clinoptilolite and Jumunjin-sand with 20 : 80 weight ratio varying particle size of clinoptilolite. The maximum permeability(1${\times}$10$\^$-4/-5${\times}$10$\^$-5/cm/s) was achieved in the specimen made of 0.42-0.85 mm clinoptilolite and sand.

• Korean Chemical Engineering Research
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• 제51권1호
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• pp.1-9
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• 2013

제올라이트 촉매를 이용한 알킬 방향족 화합물의 전환은 현대 석유화학 산업에서 큰 비중을 차지한다. 본 총설에서는 제올라이트의 구조적 물리화학적 특성에 따른 알킬 방향족 화합물 전환 반응의 기구에 대해 고찰하였다. 제올라이트의 형상선택성은 알킬 방향족 화합물 전환에 있어서 반응중간체의 생성을 조절함으로써 반응 기구 및 생성물 분포에 직접적인 영향을 미친다. 다양한 알킬 방향족 화합물의 전환 반응에 대하여 반응 중간체의 구조 및 역할에 대한 고찰을 통해 지금까지 알려진 반응기구들을 정리하였다. 아울러 제올라이트 촉매를 기초로 하는 향후 석유화학 공정 개발에 대한 전망을 기술하였다.

• KSBB Journal
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• 제18권2호
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• pp.140-144
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• 2003

제올라이트로 충진된 수직 흐름 갈대 여과상에 인공하수를 주입하면서 처리효율을 조사하였다. 여과상 표면적 $m^2$당 1일 314 L의 인공하수가 6시간마다 10분 동안 간헐적으로 주입되었다 각 항목별 연중 평균 처리효율은 CO $D_{Cr}$ , 95.1%, T-N 49.5%, N $H_4$$^{+}$-N 99.4%, T-P 56.4%이었다. T-N의 처리효율은 가동 시간이 경과함에 따라 현저하게 감소하였다. 여과상의 상층에서 많은 인이 흡착되었으며 흡착된 인 중 대부분은 Fe-p, Ca-P와 환원가용성 Fe-P이었다.

• KSBB Journal
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• 제30권3호
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• pp.114-118
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• 2015

In this study, we have developed a microbe-carrier that combined Desulfovibrio desulfuricans and zeolite for removal of Zn and As in contaminated seawater. Desulfovibrio desulfuricans, one of the sulfate-reducing bacteria (SRB) microorganism was exhibited stable growth characteristics in highly salted water and strong resistance to Zn and As contaminated seawater. Moreover, zeolites are one of the most useful carrier to remove heavy metals from wastewaters. The results showed that SRB immobilized zeolite carrier can enhance removal ratio of Zn and As. In addition, heavy metals tended to be better removed in medium at conditions of $37^{\circ}C$. In case of heavy metal concentration, they were effectively removed ranging from 50 to 100 ppm. These results show that SRB-zeolite carriers hold great potential to remove cationic heavy metal species from industrial wastewater in marine environment.

• 공업화학
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• 제5권1호
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• pp.24-29
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• 1994

모더나이트와 크리노프티로라이트가 혼재되어 있는 한국산 천연 제올라니트(경북 구룡포산)로부터 제올라이트 X를 합성하였다. 원료를 열처리한 결과 크리노프티로라이트는 없어지고 모더나이트만 남았다. 2N-8N의 염산으로 알루미늄을 추출하거나 혹은 열처리한 국산 천연 제올라이트에 NaCl과 $NaAlO_2$ 및 NaOH를 첨가한 혼합용액을 $95^{\circ}C$에서 12~36시간 동안 반응시켜 제올라이트 X를 얻었다. 염산으로 전처리한 시료 25g을 3.5g NaCl, 8g $NaAlO_2$와 6N NaOH 50ml의 혼합용액으로 $95^{\circ}C$에서 24시간 반응시킨 것이 제올라이트 NaX의 최대수율을 나타내었다.