• Title/Summary/Keyword: 제올라이트 X

Search Result 192, Processing Time 0.023 seconds

Adsorption of Heavy Metal Ions by Synthesized Zeolite 4A using Bituminous Coal Fly Ash (유연탄 비산회로부터 합성한 제올라이트 4A에 의한 중금속 이온의 흡착)

  • 김상호;연익준;김광렬
    • Journal of environmental and Sanitary engineering
    • /
    • v.14 no.3
    • /
    • pp.63-70
    • /
    • 1999
  • A study on the zeolite synthesized of bituminous coal fly ash from power plant has been carried out to reuse industrial waste. The synthesized zeolite was proved to be 4A type by means of the X-ray diffraction analysis and the degree of crystallinity was found to be higher than 90%. Then the synthesized zeolite was used as an adsorbent to remove the heavy metal ions in the CU, Pb, and Cd containing wastewater and water. Also, adsorption characteristics and kinetics of synthesized zeolite in the each metal ion solutions were studied. In each ion solutions, the adsorbed amounts of Pb, Cd, and Cu to the unit weight of synthesized zeolite were 141.6, 118.8, and 131.4mg/g respectively when each metal ion concentration was 500mg/L solution. The adsorption kinetics was fitted well to the Freundlich isotherms. The value of l/n for Pb, Cd, and Cu and 0.27, 0.50, and 0.66, respectively. Those results showed that the synthesized zeolite could be used as an adsorbent to remove single heavy metal ions in the wastewater and water. The heats of adsorption, H values of Pb, Cd, and Cu were 4.87, 14.95, and 18.23kacl/mol by the Henry-van't Hoff equation.

  • PDF

양이온 물질로 오염된 지하수 정화를 위한 반응벽체 개발 : 제올라이트의 적용성 평가

  • 이승학;이재원;김시현;박준범;박상권
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2001.09a
    • /
    • pp.23-26
    • /
    • 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.

  • PDF

Zeolitification Characteristics of Coal Fly Ash by Amount of Na2CO3 Using the Fusion/Hydrothermal Method (용융/수열합성법으로부터 Na2CO3 첨가량에 따른 석탄비산재의 제올라이트화 특성)

  • Lee, Chang-Han
    • Journal of Environmental Science International
    • /
    • v.28 no.6
    • /
    • pp.553-559
    • /
    • 2019
  • In this study, zeolitic materials at $Na_2CO_3/CFA$ ratio of 0.6 - 1.8 were synthesized from coal fly ash from a thermal power plant using a fusion/hydrothermal method. The zeolitic materials were found to have cubic crystals structure and X-ray diffraction (XRD) peaks of Na-A zeolite by XRD and SEM analysis. When the zeolitic materials were synthesized from the coal fly ash, the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratios of 0.9-1.8 had the same location as the XRD peaks of commercial Na-A zeolite. The XRD peaks of the Na-A zeolite ($Na_{12}Al_{12}Si_{12}O_{48}27.4H_2O$) were confirmed in the $2{\theta}$ in the range of 7.18-34.18. However, it was also confirmed that peaks of $CaCO_3$, an impurity inhibiting synthesis of Na-A zeolite from CaO and $Na_2CO_3$ in the coal fly ash, occurred in the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratio of 1.5-1.8. The crystallinities of the zeolitic materials tended to increase gradually within the $Na_2CO_3/CFA$ ratio range of 0.6-1.8.

Variation of Copper and Zinc-Ion Adsorption Capacity via Zeolitification of Jeju Scoria (제주 스코리아의 제올라이트화에 따른 구리와 아연 이온의 흡착 용량 변화)

  • Chang-Han Lee;Sang-Kyu, Kam;Chul-Goo Hu
    • Journal of Environmental Science International
    • /
    • v.32 no.8
    • /
    • pp.563-572
    • /
    • 2023
  • Scoria from Jeju-island (Jeju scoria) was converted into zeolitic material (Z-SA) via zeolitification using the fusion/hydrothermal method. Jeju scoria could be synthesized into Z-SA to from a surface covered with Na-A zeolite crystals, which was confirmed through an analysis of X-ray diffraction peak patterns and scanning electron microscopy images. Jeju scoria and Z-SA were employed as adsorbents to evaluate the adsorption rate and adsorption capacities for Cu2+ and Zn2+ ions. The adsorption rates and isothermal adsorption capacities could be well fitted by the pseudo-quadratic adsorption kinetics and Langmuir adsorption isotherm, respectively. The maximum adsorption capacities (qm) of Z-SA for Cu2+ and Zn2+ ions were found to be 163.36 mg/g and 120.51 mg/g, respectively, using the Langmuir adsorption isotherm. When Z-SA is synthesized from Jeju scoria via zeolitification using the fusion/hydrothermal method, Z-SA exhibits an adsorption capacity that is more than approximately 100 times the value exhibited by Jeju scoria. As a result, the synthesized Z-SA was regarded as an effective, economic adsorbent.

Adsorption Characteristics of Ammonia-Nitrogen by Zeolitic Materials Synthesized from Jeju Scoria (제주 스코리아로부터 합성한 제올라이트 물질에 의한 암모니아성 질소의 흡착 특성)

  • Lee, Chang-Han;Hyun, Sung-Su;Kam, Sang-Kyu
    • Journal of Environmental Science International
    • /
    • v.29 no.12
    • /
    • pp.1261-1274
    • /
    • 2020
  • The characteristics of ammonia-nitrogen (NH4+-N) adsorption by a zeolitic material synthesized from Jeju scoria using the fusion and hydrothermal method was studied. The synthetic zeolitic material (Z-SA) was identified as a Na-A zeolite by X-ray diffraction, X-ray fluorescence analysis and scanning electron microscopy images. The adsorption of NH4+-N using Jeju scoria and different types of zeolite such as the Z-SA, natural zeolite, and commercial pure zeolite (Na-A zeolite, Z-CS) was compared. The equilibrium of NH4+-N adsorption was reached within 30 min for Z-SA and Z-CS, and after 60 min for Jeju scoria and natural zeolite. The adsorption capacity of NH4+-N increased with approaching to neutral when pH was in the range of 3-7, but decreased above 7. The removal efficiency of NH4+-N increased with increasing Z-SA dosage, however, its adsorption capacity decreased. For initial NH4+-N concentrations of 10-200 mg/L at pH 7, the adsorption rate of NH4+-N was well described by the pseudo second-order kinetic model than the pseudo first-order kinetic model. The adsorption isotherm was well fitted by the Langmuir model. The maximum uptake of NH4+-N obtained from the Langmuir model decreased in the order of Z-CS (46.8 mg/g) > Z-SA (31.3 mg/g) > natural zeolite (5.6 mg/g) > Jeju scoria (0.2 mg/g).

Crystal Structure of a Carbon Monoxide Sorption Complex of Fully $Ca^{2+}$-Exchanged Zeolite X (제올라이트 X 착물의 결정구조)

  • Lee, Seok-Hee;Kim, Yong-Gwon;Jeong, Gyoung-Hwa;Kim, Nam-Seok;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
    • /
    • v.22 no.1
    • /
    • pp.28-34
    • /
    • 2005
  • The structure of a carbon monoxide sorption complex of dehydrated fully $Ca^{2+}$-exchanged zeolite X, $|Ca_{46}(CO)_{27}|[Si_{100}Al_{92}O_{384}]$-FAU, has been determined in the cubic space group $Fd\;{\overline{3}}$ at $21^{\circ}C$ (a = 24.970(4) ) by single-crystal X-ray diffraction techniques. The crystal was prepared by ion exchange in a flowing stream of 0.05 M aqueous ${Ca(NO_3)_2}$ for three days, followed by dehydration at $400^{\circ}C$ and $2{\times}10^{-6}$ Torr for two days, and exposure to 100 Torr of zeolitically dry carbon monoxide gas at $21^{\circ}C$. The structure was determined in this atmosphere and was refined, using the 356 reflections for which $F_o$ > $4{\sigma}(F_o)$, to the final error indices $R_1$ = 0.059 and $wR_2$ = 0.087. In this structure, $Ca^{2+}$ ions occupy three crystallographic sites. Sixteen $Ca^{2+}$ ions fill the octahedral site I at the centers of hexagonal prisms (Ca-O = 2.415(7) ${\AA}$). The remaining 30 $Ca^{2+}$ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 3 and 27 ions. Each of these $Ca^{2+}$ ions coordinates to three framework oxygens, either at 2.276(10) or 2.298(8) ${\AA}$, respectively. Twenty-seven carbon monoxide molecules have been sorbed per unit cell, three per supercage. Each coordinates to one of the latter 16 site-II $Ca^{2+}$ ions: C-Ca = 2.72(8) ${\AA}$. The imprecisely determined N-C bond length, 1.26(14) ${\AA}$, differs insignificantly from that in carbon monoxide(g), 1.13 ${\AA}$.

A Study on the Modification of NH4+Y-zeolite for Improving Adsorption/Desorption Performance of Benzene (NH4+Y-zeolite의 개질을 통한 벤젠 흡·탈착 성능 증진 연구)

  • Jang, Young Hee;Noh, Young Il;Lee, Sang Moon;Kim, Sung Su
    • Clean Technology
    • /
    • v.25 no.1
    • /
    • pp.33-39
    • /
    • 2019
  • A.C (activated carbon) is mainly used to remove VOCs (volatile organic compounds), however, it has many problems such as fire risk due to increasing of adsorbent surface temperature during VOCs ad/desorption, increased cost by frequent replacement cycles requirement and performance degradation when containing moisture. In order to solve these problems, many researches, hydrophobic zeolite adsorbents, have been reported. In this study, $NH_4{^+}Y$-zeolite was synthesized with Y-zeolite through steam treatment and acid treatment, which is one of the hydrophobic modification methods, to secure high surface area, thermal stability and humidity resistance. The Y, Y-550-HN, Y-600-HN and Y-650-HN had adsorption capacities of $23mg\;g^{-1}$, $38mg\;g^{-1}$, $77mg\;g^{-1}$, $61mg\;g^{-1}$. The change of Si/Al ratio, which is an index to confirm the degree of modification, was confirmed by XRF (X-ray fluorescence spectrometer) analysis. As a result, the adsorbtion performance was improved when Y-zeolite modified, and the Si/Al ratio of Y, Y-550-HN, Y-600-HN, Y-650-HN were increased to 3.1765, 6.6706, 7.3079, and 7.4635, respectively. Whereas it was confirmed that structural crystallization due to high heat treatment temperature affected performance degradation. Therefore, there is an optimal heat treatment temperature of Y-zeolite, optimum modification condition study could be a substitute for activated carbon as a condition for producing an adsorbent having high durability and stability.

Depth-dependent Variations in Elemental and Mineral Distribution in the Deep Oceanic Floor Sediments (WP21GPC04) near the Mariana Trench in the Western Pacific Ocean (마리아나 해구에 인접한 서태평양 심해평원의 정점 WP21GPC04에서 수집된 해양 퇴적물의 깊이에 따른 원소 및 광물 분포 변화)

  • Junte Heo;Seohee Yun;Jonguk Kim;Young Tak Ko;Yongjae Lee
    • Economic and Environmental Geology
    • /
    • v.56 no.5
    • /
    • pp.581-588
    • /
    • 2023
  • This study reports depth-dependent elemental distribution and mineral abundance of the oceanic sediment sample (WP21GPC04) near the Mariana Trench collected during the WP21 expedition in 2021. The elemental distribution determined by μ-XRF shows no significant differences with varying depth, with an average SiO2 53.91 wt%, FeO 4.48 wt%, Al2O3 16.56 wt%, MgO 2.56 wt%, CaO 4.79 wt%, Na2O 3.52 wt%, K2O 5.48 wt%, similar to the average chemical composition of global subducting sediments (GLOSS). The mineral abundances analyzed using synchrotron XRD, however, vary with depth. While quartz, mica, and plagioclase were identified at all depths, chlorite was found at shallow depths, and zeolite group minerals, phillipsite and heulandite, showed a gradual change in phase fraction with depth. This suggests a change in sedimentation and alteration environments in the region, or the potential for coexistence emerges due to similar sediment stability. Overall, this study will provide a basis for the future investigations on the evolution of sedimentary environment near the Mariana Trench in the western Pacific Ocean and the phase distribution and the behavior of subducting oceanic sediments, which will affect the lithological and geochemical characteristics of the Mariana susduction system.

Synthesis of Sodalite from Water Glass: Effect of the Composition of Synthetic Mixtures on Its Crystallinity and Crystallite Size (물유리에서 소달라이트의 합성: 합성모액 조성이 결정화도와 입자 크기에 미치는 영향)

  • Bae, Song Eun;Seo, Gon;Song, Mee Kyung;No, Kyoung Tai
    • Korean Chemical Engineering Research
    • /
    • v.47 no.4
    • /
    • pp.424-429
    • /
    • 2009
  • The effects of $Na_2O$, $SiO_2$ and $H_2O$ contents of the synthetic mixtures prepared from water glass on the crystallinity and crystallite size of sodalite were studied. The composition of the synthetic mixtures described by $x\;Na_2O{\cdot}y\;SiO_2{\cdot}Al_2O_3{\cdot}z\;H_2O$ was varied within x=2.5~7.5, y=1.4~3.0, z=140~400. The hydrothermal reaction was carried out at $140^{\circ}C$ for 2 days. High content of $Na_2O$ resulted in the high crystallinity and small crystallite of sodalite. The $SiO_2/Al_2O_3$ molar ratios of around 2 were suitable for the synthesis of sodalite, and produced zeolite species were varied by the $H_2O$ content. Sodalite was mainly obtained with a high crystallinity from the synthetic mixtures with $SiO_2/Al_2O_3$ molar ratio of around 2 and high content of $Na_2O$. The high content of sodium ions caused a decrease in the particle sizes because of their role of structure directing agent.

Effect of the Additives on Direct Dimethyl Carbonate Synthesis using Methanol and Carbon Dioxide over Ce0.8Zr0.2O2 Catalyst (Ce0.8Zr0.2O2 촉매 상에서 메탄올과 이산화탄소를 이용한 디메틸카보네이트 직접 합성에 대한 첨가제의 영향)

  • Han, Gi Bo;Park, No-Kuk;Yoon, Suk Hoon;Lee, Tae Jin
    • Korean Chemical Engineering Research
    • /
    • v.45 no.6
    • /
    • pp.554-559
    • /
    • 2007
  • In order to improve the reactivity for the direct synthesis of dimethyl carbonate (DMC) using methanol and carbon dioxide, the various additives were used in the DMC synthesis using $Ce_{0.8}Zr_{0.2}O_2$ catalyst, and then effect of the additives was investigated. The various additives were molecular sieves 3A and the compounds having the various functional groups such as sulfate, carbonate, nitrate and phosphate. As a result, the compound such as $K_2SO_4$ and $Na_2SO_4$ having sulfate group were the most effective additive among the various additives. When $K_2SO_4$ was used as an additive in the direct synthesis of DMC, the amount of DMC was about 0.91 mmol, which was the highest mount of DMC among using only-$Ce_{0.8}Zr_{0.2}O_2$ catalyst and the various additives.