• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.442-448
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• 2012

The effects of zeolite-type catalysts addition on the thermal decomposition of the PP resin have been studied in a thermal analyzer, a Pyrolyser GC-mass, and a small batch reactor. The zeolite type catalysts tested were natural zeolite, used FCC catalyst, and ZSM-5. As the results of TGA experiments, the pyrolysis starting temperature for PP varied in the range of $330{\sim}360^{\circ}C$ according to the heating rate. Addition of the zeolite type catalysts in the PP resin increased the pyrolysis rate in the order of used FCC catalyst> natural zeolite> ZSM-5 > PP resin. Adding the used FCC catalyst in the PP reduced most effectively the pyrolysis finishing temperature. In the PY-G.C. mass experiments, addition of zeolite type catalysts decreased the molecular weight of pyrolyzed product. In the batch system experiments, the mixing of used FCC catalyst enhanced best the initial yield of fuel oil, but the final yield of fuel oil was 2% higher in the case of mixing of natural zeolite. Also in the carbon number analysis, used FCC catalyst was the most useful one in this experiments for fuel oil.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.54-61
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• 2019

In this study, a magnetic adsorbent was synthesized by growing ferrite nanoparticles substituted with metals (Me = Co, Mn, Ni) on zeolite 4A for the efficient separation of waste adsorbents present in the solution after the adsorption of Cu(II). The metal ferrite grown on the surface of zeolite was prepared by solvothermal synthesis. Characteristics of the magnetic adsorbent were analyzed by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and physical property measurement system (PPMS). The saturation magnetization of the A type zeolite coated with Co-ferrite (CFZC) was the highest at 5 emu/g and the Cu(II) adsorption performance was also excellent. The adsorption results of Cu(II) on CFZC were well fitted by the Langmuir model at 298 K. Also, the adsorption of Cu(II) on CFZC follows a pseudo-second order kinetic. The Gibbs free energy values (${\Delta}G^0$) ranging from -4.63 to -5.21 kJ/mol indicates that the Cu(II) adsorption is spontaneous in the temeprature range between 298 and 313 K.

• Korean Journal of Materials Research
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• v.11 no.12
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• pp.1009-1013
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• 2001

The effects of coupling agent on the interface characteristics between epoxy resin and natural zeolite were studied by SEM, optical microscope and universal testing machine (UTM). Epoxy resin as a matrix was diglycidyl ether of bisphenol A (DGEBA)/4,4'-methylene dianiline (MDA)/malononitrile (MN) system and natural zeolite as an inorganic fillet was produced in Korea. With the increment of zeolite content, tensile strength decreased and it was due to the different elastic moduli of two materials. When external stress was loaded on the composites, the stress concentrated on the weakly bonded interface and crack grew easily. To improve the interface characteristics, the surface of the natural zeolite was treated with the silane coupling agent and it was found that the tensile strength was increased. The morphology of the interface showed that the bonding characteristics were modified by coupling agent.

• Journal of Environmental Science International
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• v.1 no.2
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• pp.167-175
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• 1992

This study was conducted for an efficient utilization of waste fly ash obtained from the power plant. Fly ash was used for synthesizing zeolite. Na-Pl zeolite could be easily synthesized from waste fly ash and showed the potential to remove heavy metal ions. The synthetic zeolite showed good adsorption property for heavy metal much better than raw fly ash and natural zeolites. Na-Pl exhibited the high adsorption efficiency with a maximum value of 260 Pb mg/g and strong affinity for Pb2+ ion. The metal ion selectivity of Na-Pl was determined in a decreasing order : $Pb^{2+}$>$Cd^{2+}$>$Cu^{2+}$+>$Zn^{2+}$>$Fe^{3+}$

• Journal of environmental and Sanitary engineering
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• v.18 no.3 s.49
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• pp.43-47
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• 2003

The desorption characteristics of NaY zeolite, of which Si/Al ratio is 2.36, was measured at 25${\circ}$C and 150${\circ}$C so as to be used practically as a adsorbent for separation of sulfur oxides from flue gas, for which adsorption and desorption cycles at 25${\circ}$C were repeated four times and that at 150${\circ}$C was done one time. As a result it took 30.8 at 150${\circ}$C and 164.1 minutes in average at 25${\circ}$C to reach equilibrium condition. It means that regeneration of the NaY zeolite can be done below 150${\circ}$C so that zeolite can be used for flue gas desulfurization.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.2
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• pp.167-175
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• 1997

This study was conducted for an efficient utilization of waste fly ash obtained from the power plant. Fly ash was used for synthesizing zeolite. Na-P1 zeolite could be easily synthesized from waste fly ash and showed the potential to remove heavy metal ions. The synthetic zeolite showed good adsorption property for heavy metal much better than raw fly ash and natural zeolites. Na-P1 exhibited the high adsorption efficiency with a maximum value of 260 Pb mg/g and strong affinity for $Pb^{2+}$ ion. The metal ion selectivity of Na-P1 was determined in a decreasing order : $Pb^{2+}>Cd^{2+}>Cu^{2+}>Zn^{2+}>Fe^{3+}$.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.248-254
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• 2012

During the monolayer assembly of zeolite microcrystals using sonication with stacking (SS) method, the factors that govern the degree of close packing (DCP) between the microcrystals, the rate of attachment (rA) of microcrystals onto the substrate, the degree of coverage (DOC), and the binding strength (BS) between each crystal and the substrate were investigated for each mode of binding linkage (MBL). The tested MBLs were covalent linkage (CL), ionic linkage (IL), and polyelectrolyte-mediated ionic linkage (p-IL). Unlike the monolayers of zeolite crystals assembled on glass with a covalent linkage, the strong BS, very high DOC, and very high DCP do not decrease during monolayer assembly on glass through ionic linkages. This results indicate that the surface migration of crystals undergo linkage-nondestructively when crystals were attached to the substrates through ionic linkages.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.2
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• pp.146-154
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• 2003

The hybrids of zeolite and metal hydride were prepared to improve the absorption properties as media for hydrogen storage. The zeolites which was deposited on the surface by metal hydride vapor showed excellent absorption properties and sodalite was proved to be better than zeolite-A in the reaction velocity and hydrogen storage capacity. This suggests the metal hydride could be used effectively as catalytic active material for enhancing the hydrogen storage in zeolite containing $\alpha$-cages and furthermore the hydrogen molecules have preference tobe occluded in their cavities containing $\alpha$-cages more effectively than that containing a and $\beta$-cages.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.31-38
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• 2015

This study aims to assess the effectiveness of limestone, zeolite, and crushed concrete as capping material to block the release of heavy metals (As, Cu, Cr, Ni, and Pb) and reduce the sediment oxygen demand. The efficiency of limestone, zeolite, and crushed concrete was evaluated in a reactor in which a 1-cm thick layer of capping materials was placed on the sediments collected from Inchon north harbor. Dissolved oxygen concentration and heavy metal concentration in seawater above the uncapped sediments and capping material were monitored for 17 days. The sediment oxygen demand was in the following increasing order: crushed concrete ($288.37mg/m^2{\cdot}d$) < zeolite ($428.96mg/m^2{\cdot}d$) < limestone ($904.53mg/m^2{\cdot}d$) < uncapped ($981.34mg/m^2{\cdot}d$). The capping materials could reduce the sediment oxygen demand by blocking the release of biochemical matters consuming dissolved oxygen in seawater. It was also shown that zeolite and crushed concrete could effectively block the release of Cu, Ni, and Pb but those were not effective for the interruption of As and Cr release from marine contaminated sediments.

• Journal of Radiation Protection and Research
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• v.10 no.1
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• pp.3-13
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• 1985

The sorption behavior of some typical fission products such as Cs-137, long-lived radionuclide; Ce-144, rare-earth element; and Co-60, corrosion product on zeolite A, zeolite F-9 (faujasite) and amorphous zeolite was determined with the salt concentrations, 0.01 M- to 2.0 M- nitric acid and ammonium nitrate, and the shaking time, 15 minutes interval from 15 minute to 90 minute. Kd values were obtained through the batch experiment. In conclusion, the optimal conditions for isolation and removal of the typical radionuclides are as following: zeolite, amorphous zeolite; concentration, $0.01\;M-HNO_3\;and\;0.1\;M-NH_4NO_3$; pH4; shaking time, one hour; the most effective species, Cs-137.