• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.1-8
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• 2005

In this study, $TiO_2$ powders were prepared by hydro-thermal synthesis with titanium tetra isopropoxide. The prepared $TiO_2$ and the commercial $TiO_2$(P-25, Degussa) were by impregnating $H_2PtCl_6$ solution or the leached solution from the waste catalytic converter of automobile. Modified photocatalysts were analyzed by ICP-AES, UV-DRS, XRD, SEM. And band-gap energy of modified photo-catalyst was found to decreased to 1.76eV and basic structure was changed upon modification by leached solution. Modified photocatalysts were coated on the wallpaper after using mixed solution with adhesive materials(PVC). And then to know the modified photo catalysts tested the reactivity and quantum efficiency in the mixed gas with NO as reactants in the photo catalytic reactor. In the gas phase, photo-catalytic activity of NO was the highest for modified P-25 catalysts(P-25(w)) that P-25(w) was impregnated by leached solution of wasted catalytic converter.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.567-573
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• 2012

Compared with the natural marble, the artificial marble has the advantages of excellent appearance, high degree of finish, even color, fine pressure and wear resistance, bear erosion and weathering, etc. It can be widely used in kitchen countertops, bath vanity tops, table tops, furniture, reception desks, etc. However, large amounts of artificial marble waste such as scraps or dust have been generated from sawing and polishing processes in artificial marble industry. Waste from artificial marble industry is increasing according to demand magnification of luxurious interior material. Artificial marble wastes can be recycled as aluminum oxide used as raw materials in electronic materials, ceramics production, etc., and methyl methacrylate(MMA) which become a raw material of artificial marble by pulverization, pyrolysis and distillation processes. The characteristics of artificial marble wastes was analyzed by using TGA/DSC and element analysis. Crude aluminum oxide was obtained from artificial marble waste by pulverization and thermal decomposition under nitrogen atmosphere. In this work, Box-Behnken design was used to optimize the pyrolysis process. The characteristics of crude aluminum oxide was evaluated by chromaticity analysis, element analysis, and surface area.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.6
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• pp.305-311
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• 2012

In order to recycle the coal bottom ashes (denoted as BA) produced from a thermal power plant, the artificial aggregates (denoted as AAs) containing BA and red clay were manufactured, and the physical properties of AAs were studied as a function of particle size of BA and batch compositions. As-received BA had 38 wt% coarse particles of above 2 mm and many unburned carbon mass and porous slag particles were co-existed. So the two particle sizes of BA, the fine (< 100 ${\mu}m$) and coarse (< 2 mm), were prepared by milling and screening process. The AAs containing fine BA sintered at $1100{\sim}1200^{\circ}C$ had the higher bulk density and lower water absorption compared to the specimen made of coarse BA. The inside core of AAs manufactured by using coarse BA showed nonuniform and porous microstructure, while the AAs made of fine BA had a uniform and dense microstructure. In this research, the AAs containing BA and red clay with various bulk density (1.2~1.7) and water absorption (13~21 %) could be manufactured by controlling the particle size of BA and batch compositions, so the AAs of various physical properties could be applied to the wide fields such as construction/building materials in near future.

• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.51-58
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• 1993

The integrated solid waste management for Seoul Metropolitan city can be established on the basis of the following hierarchy of priorities: 1. Efforts for source reduction should be propelled by both government and citizens to achieve the effects of resource conservation. The adequate production and consumption which are environmentally amenable and sustainable can be induced by the reasonable imposition of deposit money for waste treatment to one-time use products. To accomplish source reduction effectively, the induction of legal and institutional regulation of producer and consumer participation is requisite. 2. For resource recovery, wastes generated should be recycled as far as practicable. Community residents are responsible to separate discharge, the authorities concerned have responsibility of separate collection, and recycling industry should be assissted through tax reduction and financing. Resource separation facilities can be constructed at Kimpo Metropolitan landfill site for wastes not separately collected due to some unavoidable circumstances. 3. Garbage should be composted. Garbage is uneconomical for incineration, because it has high moisture content and low calorie, thus there is no reason for the incineration of garbage even though garbage is classified into combustibles. Composting facilities can be located at sites which are not densely populated and easily accessible to transportation, for example, Kimpo Metropolitan landfill site. Compost produced can be managed by the authorities for the use of fertilizer to a green tract of suburban land and farms. 4. Nonhazardous combustible wastes not recyclable can be utilized for thermal recovery at the incinerators which are completely equipped with pollution control devices. According to the trend of local autonomy and the equity principle of local autonomous entities, incineration facilities of minimal capacity required can be constructed at each districts of Seoul Metropolitan city which have organized local assembly. In case of Yangcheon district, the economically combustible waste quantity is about 260 tons/day which exceeds 150 tons/day, the incineration capacity of existing facility. But, from now on, waste quantity can be reduced substantially by the intensive efforts of citizens for source reduction and recycling and the institutional support of administrative organizations. Especially, it is indispensable for the government to constitute institutional and technological bases that can recycle paper and plastics form 43% of waste generated. A good time for constructing of incineration facilities for municipal solid waste can be postponed to the time that pollution control technologies of domestic enterprises are fully developed to satisfy the standards of air pollution prevention, because the life expectancy of Kimpo Metropolitan landfill site is about 25 years. Within this period, institutional improvements and technological advancements can be attained, while the air qual. ity of Seoul Metropolitan city can be ameliorated to the level to afford incineration facilities. 5. For final disposal, incombustibles and ash are landfilled sanitarily at Kimpo Metropolitan landfill site.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.103-106
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• 2014

Recycling of bottom ash from municipal solid waste (MSW) incinerator has been strictly limited due to its composition of high level chlorine and other unfavorable substances. The composition of MSW has been, however, changed after the introduction of garbage-bag sales system, extended producer responsibility (EPR) policy and the prohibition of direct landfill of food waste. Recent waste shows reduced moisture and chlorine content, increased calorific value due to the separation of food waste, incombustible materials and PVC. The main purpose of this study is to investigate the trend of composition changes of MSW incinerator bottom ash and to compare the analytical results with those before the separation system was introduced. CaO content of bottom ash, one of the major component of cement clinker, increased from 26.7% in 2001 to 34.0% in 2006. The chlorine content showed a dramatic decrease from 1.84% in 2001 to 0.00655% in 2006, which is closely compatible with that of the fly ash of coal-utilizing thermal power plants, which is mainly due to the changes of MSW composition. It is eventually considered that there is a possibility of utilizing the incinerator bottom ash as a raw material of cement clinker feed substances.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.27-33
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• 2016

Phenolic resin has excellent heat resistance and good mechanical properties as a thermosetting resin. However, its thermosetting characteristics cause it to produce a non-recyclable waste in the form of sprue and runner which is discarded and represents up to 15~20% of the overall products. Forty thousand tons of phenolic resin sprue and runner are disposed of (annually). The (annual) cost of such domestic waste disposal is calculated to be 20 billion won. In this study, discarded phenol resin scraps were pulverized and treated by silanes to improve their interfacial adhesion with HDPE. The sizes of the pulverized pulverulent bodies and fine particles were (100um~1000um) and (1~100um), respectively. The pulverized phenol resin was treated with 3-(methacryloyloxy) propyltrimethoxysilane and vinyltrimethoxy silane and the changes in its characteristics were evaluated. The thermal properties were evaluated by DSC and HDT. The mechanical properties were assessed by a notched Izod impact strength tester. When the silane treated phenol resin was added, the heat distortion temperature of HDPE increased from $77^{\circ}C$ to $96^{\circ}C$ and its crystallinity and crystallization temperature also increased. Finally, its impact strength and tensile strength increased by 20% and 50%, respectively, in comparison with the non-treated phenol resin.