• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.142-145
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• 1999

We confirm that when A-type zeolite supporting silver lone is placed in ion-exchanged distilled water, silver ions is eluted and eluted silver ions generates hydroxyl-radical (.OH) and hydro-radical (.H) continuously, the amount of those is proportion to the silver-ion concentration. Hydroxyl-radical is not generated by super-oxide anion-radical (.O2) but by directly dissolved water. To know such a above discussed mechanism, we prepare A-type zeolite supporting silver ions, and measure the amount of the eluted silver tons by atomic absorption spectroscopy and the generated radical by ESR The radical generated by A-type zeolite supporting silver ions is discussed in the application of elecrical and electronic materials.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.59-63
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• 2012

The use of dry chemical powder has been increased as it can be stored for a long period and sustain in stable condition compared to gas or liquid phase extinguishing agents. A new type of dry chemical powder using Zeolite was produced in the research. Chemical powder was adsorbed into Zeolite 13X, a porous material appearing negative catalytic effect, to create extinguishing powder obtaining core shell structure and measured physical properties and run a small scale fire extinguishment. SEM, XRD, TA analysis was also executed, and extinguishing characteristics were measured by fire extinguishing experiment on oil pool fire. The experiment showed that the average particle size of Zeolite 13X was equivalent, indicating about $3{\pm}1{\mu}m$ and thermal analysis result illustrated that Zeolite 13X showed exothermic reaction peaks at $900^{\circ}C$ due to solid-state transformation. Extinguishing characteristics on oil fire of $NaHCO_3$/Zeolite 13X and $NH_4H_2PO_4$/Zeolite were improved, influenced by adsorbed extinguishing powders on Zeolite 13X and Zeolite 13X that contains high phase transition temperature.

• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.1-5
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• 2005

Nitrate reduction with zero valent iron $(Fe^0)$ has been extensively studied, but the proper treatment for ammonium byproduct has not been reported yet. In groundwater, however, ammonium is regarded as contaminant species, and particularly, its acceptable level is regulated to 0.5 mg-N/L. for drinking water. This study is focused on developing new material to reduce nitrate and properly remove ammonium by-products. A new material, Fe-loaded zeolite, is derived from zeolite modified by Fe(II) chloride followed by reduction with sodium borohydride. Batch experiments were performed without buffer at two different pH to evaluate the removal efficiency of Fe-loaded zeolite. After 80 hr reaction time, Fe loaded zeolite showed about $60\%$ nitrate removal at initial pH of 3.3 and $40\%$ at pH of 6 with no ammonium release. Although iron filing showed higher removal efficiency than Fe-loaded zeolite at each pH, it released a considerable amount of ammonium stoichiometrically equivalent to that of reduced nitrate. In terms of nitrogen species including $NO_3-N$ and $NH_4^+-N$, Fe-loaded zeolite removed about $60\%\;and\;40\%$ of nitrogen in residual solution at initial pH of 3.3 and 6, respectively, while the removal efficiency of iron filing was negligible.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.203-209
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• 2019

A number of industrial zones in South Korea were reported contaminated by heavy metals. Such contamination could cause severe damage to the subsurface environment including soil and groundwater. The treatment of zeolite mixing with soil at the bottom of such industrial zones might prevent, or at least reduce the damage of contamination by adsorption of the heavy metals from the leakage. However, such mixtures should maintain the proper bearing capacity as a foundation fill material from the geotechnical point of view at the same time. To investigate the effect of mixtures of zeolite with local soils for the adsorption of heavy metals (Zn, Pb) and sustainability of bearing capacity, adsorption isotherm tests and direct shear test with compaction tests were performed. Results showed that the mixing zeolite with local soils effectively reduces the spreading of the heavy metal contamination when maintaining its proper geotechnical properties as a fill material of industrial zones.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.1
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• pp.1-8
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• 2021

This study is for the application of functional antibacterial packaging to fresh food. Zeolite/Zinc-polypeptide was coated on PP film at concentrations of 5%, 10%, and 15%, degree of dispersion was verified through FESEM and FT-IR analysis. In addition, the antibacterial and antifungal properties of the films were analyzed according to the control group and the concentration of coating materials. As a result, the degree of dispersion of coating material was irregular but wide, depending on the concentration of Zeolite/Zinc-polypeptide on the surface of PP film. The antibacterial effect against E. coli was over 99.9%, and the growth of R. oryzae was inhibited about 70%. Therefore, it was confirmed that Zeolite/Zinc-polypeptide had antibacterial and antifungal properties against E. coli and R. oryzae even after coated on PP film. In conclusion, Zeolite/Zinc-polypeptide coating film is expected to be effective in preventing corruption and improving the shelf life of fresh food as a functional packaging material. In order to be applied to various fresh foods in the future, storage experiments are additionally required with temperature and humidity conditions according to fresh foods.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.521-528
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• 2017

To find a recycling method for waste liquid crystal display (LCD) panel glasses, we investigated the synthesis process of zeolite with an ion exchange ability by hydrothermal reaction using waste LCD panel glass as a raw material. It was shown that the waste LCD panel glass can be used as a raw material for the production of zeolites having the ion exchange ability. Following conditions for the synthesis of the zeolite with an ion exchange ability were required : the molar ratio of Si to Al components of the waste LCD glass needs to be 2.0 to 2.8, and the temperature of $100^{\circ}C$ and reaction time of 12 hours are needed for the hydrothermal reaction. Based on the required conditions previously mentioned, the A type zeolite was synthesized when the molar ratio of the Si to Al component was 2.0, and the P type zeolite was produced when the molar ratio was 2.8. The type A zeolite synthesized by using the waste LCD panel glass showed a good ion exchange ability and heavy metal adsorption ability. Also, an excellent ion exchange capacity was observed as the crystal phase grows stably in a cubic phase.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.615-618
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• 1998

The zeolite crystals were synthesized by hydrogel process into the pore of activated carbon. The effect of activated carbon in the course of the crystallization of zeolite was investigated. The phenomena of impregnation of zeolite crystals into the pore of the activated carbon were also examined. The results show that in case of the addition of 5% of activated carbon to the aluminosilicate gel including the mole composition of zeolite A, zeolite A was purely synthesized without the existence of other type of zeolite. However, in case of the addition of 20% of activated carbon, zeolite X was purely synthesized. In the pore mouth and internal of activated carbon, zeolite crystals having the size under $1{\mu}m$ was observed. From the results of the pore size and particle size distributions, it was confirmed that the synthetic sample was the composite material impregnated by the zeolite crystals into the pore of activated carbon, not the simple mixture of zeolite and activated carbon.

• Rapid Communication in Photoscience
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• v.4 no.1
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• pp.19-21
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• 2015

Zeolite is an ideal host material for encapsulating nano-size metal catalyst species because of its defined microporous structure, prominent adsorption/condensation properties, high surface area, chemical/thermal stability, and transparency to light. In this study, $TiO_2$ photocatalyst was incorporated in highly hydrophobic Y zeolite and its photocatalytic activity was examined in the photocatalytic oxidation of olefins under UV-light irradiation using molecular oxygen as an oxygen source. $TiO_2$ nanoparticles incorporated in hydrophobic Y zeolite exhibited a markedly enhanced photocatalytic activity compared with bare $TiO_2$ owing to its excellent affinity toward organic moieties, which facilitates the mass transfer of organic substrates and allows them to efficiently access to the neighboring active $TiO_2$ surface.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.151-154
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• 2005

Laboratory column experiments for simultaneous removal of Cd and Cr(VI) are conducted using newly developed material, referred to as Fe-loaded zeolite, which has both reduction ability of iron and ion exchange ability of zeolite. Breakthrough curves were obtained from each column experiment, and described with advection-dispersion equation. Apparent parameters including $K_{app}\;and\;D_{app}$ were newly introduced for effectively describing the Cr(VI) breakthrough curve. $K_{app}$ decreased with increasing initial contaminant concentration and with decreasing flow rates. Whereas, $D_{app}$ were not significantly affected by initial contaminant concentration or flow rate.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.341-347
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• 2006

Adsorption characteristics of benzene by zeolite were investigated using irradiating microwave. Experimental apparatus was applied to a U-type fix-bed column equipped with microwave system. Zeolite, itself, seems to be inappropriated to remove benzene because of a hygroscopic property, Microwave irradiation to zeolite, however, brings about decreasing $H_{2}O$ adsorption and increasing benzene adsorption. This causes that the dipole material such as $H_{2}O$ was vibrated and heated by irradiation of microwave and desorbed from zeolite. And then, benzene starts to be absorbed by zeolite. In this study, the results showed that the selective adsorption of benzene was occurred by the microwave irradiation and the adsorption capacity of benzene was increased by increasing microwave energy. As a results, it was found that the zeolite could be used to adsorb benzene with microwave and this method make it feasible simultaneously to adsorb and desorb benzene.