• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.24-30
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• 1996

Nowadays, Government is modifying envioronment regulatons, but PC factories, having been constructed in 1990, are running out heavy cost in disposal of waste concrete, and hardly studying how accelerator curing method affects in compressive strength. In this study, possibility that waste concrete, produced in PC factory, can be used in PC products, is reviewed, and them captures strength characteristics by curing method. The results can be summed as follows. In order to recycle concrete the mix ratio of recycled aggregate to 50 percent of less than must decrease also in summer of four seasons strength gap by curing method is very small.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.222-228
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• 2024

This study aims to anal yze the social benefits of introducing a sel ective demol ition system for buil dings. Incremental revenue, incremental cost, and incremental profit for the entire nation were derived based on the calculated costs and revenues of selective demolition for a 2,400 m² apartment complex. In conducting selective demolition on a 2,400 m² building, the increase in demolition construction costs, the reduction in waste disposal costs due to the decrease in mixed waste, and the revenue obtained from recycling separated and sorted waste were comprehensively reviewed. It was calculated and analyzed that, compared to general demolition work, a total cost-saving effect of 34,727,000 KRW could be expected. Extrapolating this to the entire nation, based on the year 2020, which had the highest construction waste generation, it is estimated that the social benefits would amount to 746,782,886,000 KRW.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.2
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• pp.164-171
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• 2011

The objectives of this study are to propose a suitable treatment facility for waste energy recovery after analyzing the waste generation and disposal situation in Jejudo, to establish the plan to install the solar photovoltaics and wind power plant considering the site conditions and finally to establish the environmental energy town plan in conjunction with the existing facilities. The food waste biogas plant is selected as the treatment capacity of 200 ton/day. It is estimated that the biogas plant will produce the electricity of 7,594 MWh per year, which will reduce the greenhouse gas of 4,177 $tCO_2$ per year. The solar photovoltaics and wind power plant will produce the electricity of 13,410 MWh per year, which will reduce the greenhouse gas of 7,375 $tCO_2$ per year. Environmental energy town will give us the reduction of operating cost by centralized treatment of residues and byproducts, and by efficient utilization of produced energy.

• Journal of the Korean Dietetic Association
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• v.7 no.4
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• pp.410-425
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• 2001

This study was designed to assess the waste management practices, source-reduction programs and related tasks in elementary school foodservice in Seoul. and Kyonggi Province Areas. A questionnaire mailed to 910 school foodservice managers in Seoul and Kyonggi province: a 202% (N=184) response rate was obtained. About 83.7% of school foodservice managers were responsible for managing solid waste. Most foodservice operations take the responsibility of food waste but not packaging wastes. The average disposal cost per month per person was about 19 won and income was about 35 won. Leftovers were mainly disposed with platewaste. Platewaste was reused for the livestook feed(68.0%), and some platewaste was composted(11.6%). Source reduction programs implemented in half of school foodservice operations were adjustment of portion size', checking the plate waste', 'working with classroom teachers on waste reduction campaign', 'providing information leaflet on food waste minimization', posting education materials, 'classroom instruction about food waste minimization', and 'improving cooking method. According to factor analysis based on importance rating. slid waste management activities of elementary school foodservice operations were divided to 7 dimensions such as communication and cooperation with others', 'employee training', 'product quality control, 'yield control', plate waste control', 'purchasing', and 'public relations'. As a result of Important-Performance Analysis(IPA), sine dimensions such as 'communication and cooperation with others' and 'plate waste control were identified in Focus Here' quardrant area which need more enhanced performance.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.2
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• pp.141-145
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• 2008

Due to the uncertainties resulting from cost projection, evaluation over long term period, and adequacy of applied discount rate, the economic assessment for back-end fuel cycle is different from each organizations or individuals. In this paper, the features and limitations of some noticeable economic evaluations were investigated and analysed to contribute for the public participation and back-end fuel cycle policy related researches. As a result of analysis, we found that the reprocess and recycling is more economical than direct disposal option, but the result includes high uncertainty that depends on the input parameters.

• Journal of Environmental Science International
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• v.29 no.11
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• pp.1015-1024
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• 2020

Using the waste(sand wastr and boiler ash) in fluidized bed inciverator, lightweight aggregate concrete was produced and a recycling plan was prepated. The first, the result of the leaching test shows that the waste fluid sand and boiler ash did not exceed the effluent standard. This indicates that there is no harmful effect for recycling. The second, in the lightweight aggregate test using waste fluid sand and boiler ash, the sample that combined cement, waste fluid sand, and sand showed the highest compressive strength, and the mix proportion was 10: 7: 3. Lightweight aggregate concrete that combined cement, waste fluid sand, boiler ash, and sand had a low compressive strength by and large. The third, the same results were identified in the relation between the content of SiO₂ and that of Na₂O. As the SiO₂ content is lowered, the overall viscosity and plasticity of the concrete also decrease, which is not a good condition to form concrete. As for Na₂O, as the content increases, the viscosity of the sample and the viscosity of the cement are remarkably lowered, and the strength of the finished concrete is lowered. Therefore, it was concluded that the higher the content of SiO₂ and the lower the content of Na₂O, the more suitable it is to mix with cement to produce concrete. Fourth, from the fluidized bed incinerator currently operated by company A in city B, a total of 14,188 tons/year were discharged as of 2016, including 8,355 tons/year of bottom ash (including waste fluid sand) and 5,853 tons/year of boiler ash. The cost for landfill bottom ash and boiler ash discharged is 51,000 won/ton, and the total annual landfill cost is 723,588,000 won/ year. Assuming that the landfill tax to be applied from the year 2018 is about 10,000 won/ton, and if there is no reduction in waste disposal charge, an additional landfill tax of 141,880,000 won/year will be imposed. Consequently, the sum total of the annual landfill cost will be 865,468,000 won/year. Therefore, if the entire amount is used for recycling, the annual savings of about 8.7 billion won can be expected.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.219-227
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• 2016

As the largest source of food waste is housing, and the food waste properties are good enough to recycle, the proactive approach to conventional food waste disposal is highly regarded. This research is to examine food waste management in the Seoul Metropolitan Area (SMA) and non-SMA and to analyze the public inclination to disseminate zero-food waste system (ZFWS) with fermentation and extinction technology in multifamily housing estates. The self-administered questionnaire survey was conducted and the collected data were statistically analyzed. The main findings are summarized as follows: food waste in multifamily housing estates were retrieved by refuse truck and largely recycled for compost and forage. Also, many local governments were in favor of ZFWS, and unwilling to invest in it due to financial constraint. It's found that logistics of ZFWS is likely to be influenced by important features such as a considerable amount of cost saving, effective energy recovery, and efficient operation/management.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.34-40
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• 2012

This research has looked into the treatment process of wood waste generated from industrial waste within the region and in order to modify the problem that may occurred during the mass balance were analyzed for development of suitable solid waste recycling network regionally. As as result, quite amount of wood waste are being transferred to another region, even though a treatment facility's capacity could bear the total amount of waste generated within the area. Although the wood waste could be treated locally, it is analyzed that amount of wood waste are being transferred due to inefficient and irrational processing system between regions. It is assumed that $CO_2$ generated and loss of unnecessary fuel cost from these inefficient system is quite a lot and in order to modify this disorganized system, it will not inevitable to treat the waste based on the characteristics of each regions. Also, the wood waste recycling system should be studied with the efficient, environmental friendly processing and delivering network by minimized transfer distance and local systemizing the waste treatment system.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.153-153
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• 2010

The world is moving towards a post-carbon society and needs clean and renewable energy for sustainable development. There are many methodological approaches which are helping this shift based on analyzed data about energy resources and which focus on limited types of energy including liquid fossil, solid fossil, gaseous fossil, and biomass (e.g. IPCC Guidelines, ISO 14064-1, WRI Protocol, etc.). We should also consider environmental impact (e.g. greenhouse gas emissions, water use, etc.) and the economic cost of the renewable energy to make a better decision. Recently, researchers have addressed the environmental impact of new technologies which include photovoltaics, wind turbines, hydroelectric power, and biofuel. In this work, we analyze the environmental impact with a carbon emission factor to present a correlation between $CO_2$ emission and the cost of energy resources standardized by the energy output. In addition, we reviewed Life Cycle Assessment (LCA) as another methodology. Researchers who are studying energy systems have ignored the impacts of entire energy systems, e.g. the extraction and processing of fossil fuels. In power sector, the assessment should include extraction, processing, and transportation of fuels, building of power plants, production of electricity, and waste disposal. Therefore LCA could be more suitable tool for energy cost and environmental impact estimation.

• Journal of Radiation Protection and Research
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• v.25 no.2
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• pp.89-96
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• 2000

Nuclear fuel cycle choices and costs are important in considering energy policies, fuel diversity, security of supply and associated social and environmental impacts. Particularly, the nuclear spent fuel is very important in view of high activity and the need of long term management. This study focuses on the comparison of reprocessing and direct disposal of nuclear spent fuel in terms of cost, safety and public acceptability. The results of the study show that the direct disposal is about 7% more economical than the reprocessing. In terms of safety, the results show that the risk of vitrified HLW (high-level radioactive waste) is less than directly disposed spent fuel. For the public acceptability, both of the methods are not well understood and therefore they are not accepted. In conclusion, it is necessary to guarantee the safety of the both spent fuel processing methods through continuous development of associated technology and to have a fuel cycle policy which should consider not only the economics but also social and environmental impacts.