• Solar Energy
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• v.18 no.3
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• pp.197-203
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• 1998

A 5 ton/day pilot scale two-phase anaerobic digester was constructed and tasted to treat Korean food wastes in Anyang city. The process was developed based on 3 years of lab-scale experimental results on am optimim treatment method for the recovery of biogas and humus. Problems related to food waste are ever Increasing quantity among municipal solid wastes(MSW) and high moisture and salt contents. Thus our food waste produces large amounts of leachate and bed odor in landfill sites which are being exhausted. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert material such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 days space time at pH of about 6.5. The second, methanization reactor part of which is filled with anaerobic fillters, converted the acids into methane with pH between 7.4 to 7.8. The space time for the second reactor was 15 days. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady state operation with the maximum organic rate of 7.9 $kgVS/m^3day$ and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about $230m^3$ of biogas with 70% of methane and 80kg humus. This process is extended to full scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings.

• Resources Recycling
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• v.24 no.4
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• pp.38-49
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• 2015

The importance of recycling came to the fore by increasing of waste electrical and electronic equipment(WEEE) generation. Small WEEE recycling in particular represents a big challenge in Korea because it has various items and components. Main materials of small WEEE are typically well known for metals (copper, iron, aluminum, etc.), PCBs and plastics. Not only Korea but also overseas, the laws for small WEEE were in effect in order to recycle effectively, but the technology is not catched up with the regulation which has to recycle an allocated account of WEEE. In addition, recycling technologies and processes for small WEEE are not developed enough to recycling center properly. In that sense, if we develope the recycling process, have not only technology competitiveness but also resource conservation, improving the environment and economic profits. Therefore, through the analysis of economic value of recycled small WEEE, and current technologies both domestically and internationally, we design conceptual recycling process of small WEEE, and consider the way forward.

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.103-108
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• 2004

The present paper relates to an apparatus in which all carbonaceous material such as coal, oil, plastics and any substance having carbon atoms as part of its constituents are reformed(gasified) into syngas at temperature above $1,200^{\circ}C$(KR patent No.0391121, and PCT/KR2001/01717 and PCT/KR2004/001020). It comprises a single-stage reforming reactor without catalyst and a syngas burner as shown in Fig.2. syngas is combusted with $O_2$ gas in the syngas bunter to produce $M_2O$ and $CO_2$ gas with exothermic heat. Reaction products are introduced into the reforming reactor, reaction heat from syngas burner elevate the temperature of reactor above $1,200^{\circ}C$, and reaction products reduce carbonaceous material down to CO and $H_2$ gases. Reactants and heat necessary for the reaction are provided through the syngas burner only, Neither $O_2$ gas nor steam are injected into the reforming reactor. Reformer is made of ceramic inner lining and sst outer casing. Multiple syngas burners may be connected to the reforming reactor in order to increase the syngas output, and a portion of the product syngas is recycled into syngas burner. The present reformer as shown in Fig.2 is suitable to gasify carbonaceous wastes without secondary pollutants formed from oxidation. Further, it can be miniaturized to accompany a fuel cell system as shown in Fig.3 The output syngas may be used to drive a fuel cell and a portion of electrical power generated in a fuel cell is used to heat a compact reformer up to $1,200^{\circ}C$ so that gas/liquid fossil fuel can efficiently reformed into syngas. The fuel cell serves as syngas burner in Fig.2. The reformation reaction is sustained through recycling a portion of product syngas into a fuel cell and using a portion of electric power generated to heat the reformer for continuous operation. Such reforming reactor may be miniaturized into a size of PC, then you have a Personal Reformer(PR).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1729-1734
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• 2009

About 40 million automotive vehicles all over the world and 0.55 million in Korea were retired from use annually. Every nation is desperate to decrease environmental pollution by ELVs(End of Life Vehicles) and try to tighten the regulations. Europe passed laws requiring OEMs to increase vehicles' recovery and reuse rate to 95% by 2015 from current 84%. The ferrous parts, 75% of total automobile weight, are almost recycled whereas the remaining 25% of the non-metal -predominantly plastics as well as form, glass and rubber- and the non-ferrous materials -copper, nickel and aluminium- end up in landfills. The recycling status of non-ferrous materials represented by copper and nickel is reviewed and how much the recycling rate will be improved is calculated.

• Resources Recycling
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• v.22 no.4
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• pp.70-80
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• 2013

Waste refrigerator is the most large amount of item being recycled and the recycling process is the most complicated in WEEE (Waste Electrical and Electronic Equipment) because refrigerator is biggest product and consists of various parts and materials such as ferrous, non-ferrous, and plastics. Recently, recycling process of waste refrigerator has been being more complex since large capacity 2 door refrigerators and standing Kimchi refrigerators with various material are distributed on custom market. In addition, recycling of valuable resource from waste refrigerator is mandatory by WEEEs recycling legislation; therefore, high efficiency recycling enough for economic and environment-friendly recovery of valuable resource through present technical situation analysis and comparison of recycling technologies of waste refrigerator with advanced country.

• Advances in concrete construction
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• v.16 no.6
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• pp.291-302
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• 2023

As the first part of the body that strikes the ground during running, sports shoes are especially important for improving performance and reducing injuries. The use of new nanotechnology materials in the shoe's sole that can affect the movement angle of the foot and the ground reaction forces during running has not been reported yet. It is important to consider the material of the sole of the shoe since it determines the long-term performance of sports shoes, including their comfort while walking, running, and jumping. Running performance can be improved by polymer foam that provides good support with low energy dissipation (low energy dissipation). Running shoes have a midsole made of ethylene propylene copolymer (EPP) foam. The mechanical properties of EPP foam are, however, low. To improve the mechanical performance of EPP, conventional mineral fillers are commonly used, but these fillers sacrifice energy return. In this study, to improve the magnificence of physical education training with nanotechnology, carbon nanotubes (CNTs) derived from recycled plastics were prepared by catalytic chemical vapor deposition and used as nucleating and reinforcing agents. As a result of the results, the physical, mechanical, and dynamic response properties of EPP foam combined with CNT and zinc oxide nanoparticles were significantly improved. When CNT was added to the nanocomposites with a weight percentage of less than 0.5 wt%, the wear resistance, physical properties, dynamic stiffness, compressive strength, and rebound properties of EPP foams were significantly improved.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.553-560
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• 2018

Purpose : To investigate a disposal method of disposing contact lenses and the recognition of environmental pollution by micro plastics which may be caused by the wrong disposal method of domestic contact lens wearers. Methods : Two hundred sixty one adults(124 males, 137 females, mean age $21.48{\pm}3.14years$) were participated in this study. They were given the questionnaire survey on contact lenses purchasing place, type of contact lenses, duration of wearing contact lenses, the disposal method of disposing contact lenses and the recognition of the occurrence of environmental pollution. Results : It appeared that eyeglass shop(50.0%) and contact lens shop(48.3%) were the main purchasing places, and the most common type of contact lenses were disposable lenses(38.5%) and daily wearing lenses(52.5%). On the duration of wearing contact lenses they answered more than 5 years(29.3%), less than 1 year (26.0%), less than 1 year to less than 3 years (26.0%), and on wearing a contact lens during a week they did 1-2 days (32.0%), 1 week (28.0%), 5-6 days (22.4%) and 3-4 days (17.6%). It was shown "no(78.3%)" and "yes(21.7%)" to the questionnaire of whether they received information or education about a disposal method at the place where the contact lens was purchased, and "no(87.5%)" and "yes(12.5%)" to the questionnaire of whether they received information or education from schools, public institutions or public media such as the internet. As for the disposal methods, landfill waste(45.6%), recycled garbage(29.6%), and drainage(16.8%) from the sink or toilet responded in order. Although men were more educated and informed about disposal than women (t=3.63189, p<0.00001), women were more aware of environmental pollution(t=2.44269, p=0.01605). Conclusion : In order to reduce the environmental pollution issue caused by the contact lens which does not decompose at the sewage treatment facility and become micro plastics, it is urgent to provide information about correct disposal methods after using contact lenses and to educate contact lens wearers.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.217-223
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• 2010

In general, fiber-reinforced plastics (FRP) wastes are simply buried or burned. Landfill brings about a permanent contamination of soil due to the inability of FRP to decompose and incineration causes an issue of generating toxic gases and dusts. There have been several ways to treat the FRP wastes such as landfill, incineration, chemical recycling, material recycling and the utilization of energy from combustion. Most methods excluding material recycling are known to have critical limitations in economic, technical and environmental manners. However it is known that material recycling is most desirable among the methods handling FRP wastes. In this study, to investigate the purpose of feasibility of material recycling, various bulk molding compound (BMC) specimens were prepared with the various contents of unsaturated polyester resin binder (25, 30, 35 wt%) and the various replacement ratios of FRP wastes powder (0, 25, 50, 75, 100 wt%) substituted for filler. To evaluate the physical properties BMC specimens, various tests such as tensile strength, flexural strength, impact strength, hot water resistance and SEM imaging were conducted. As a results, mechanical strengths decreased with an increase of replacement ratio of FRP waste powder and physical properties of BMC specimens were deteriorated in the hot water resistance. The fluidity of BMC with more than 50 wt% of the replacement ratio of FRP wastes powder decreased remarkably, causing a problem in the BMC composite.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.1
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• pp.50-54
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• 2008

There are several basic classes of recycling methods for FRP boats. The main one is 'Mechanical recycling' which involves shredding and grinding of the scrap FRP in a new product. That is one of the simpler and more technically proven methods. It recently has been reported that FRP can be recycled by separating into layers instead of crushing into powder. Many researchers should be more interested in these mechanical recycling for the eligibility. Nevertheless, because resins is very useful renewable energy, most of waste FRP regenerating methods depend on incineration (reclamation) or thermal recycling (pyrolysis). FRP is made up of laminated glass- fiber (roving cloth layer) which is also very unlikely to break into each layer. If there is an extracting method which is efficient and environment friendly removing glass fiber from waste FRP, it should also solve the another urgent problem. Laminated glass-fiber which is very limited renewable, is a serious barrier to wast FRP boat regenerating. This study is to propose a new extracting method which is efficient and environment friendly waste FRP regenerating system. And it should be applied to renewable energy applications with the waste resins of FRP. Also recycling glass fiber obtained by the separation of the roving layer from waste FRP will be consider to be useful for concrete products or structures.

• 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.