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        검색결과 86

        61.
        2015.04 KCI 등재 서비스 종료(열람 제한)
        The government of each country is making a policy of expanding recycling of wastes and waste-to-energy to mitigate the greenhouse gas emissions to cope with climate change. This paper attempts to analyze the economic effects of waste disposal & materials recycling services (WDMRS) sector using 2012 input-output (IO) table published in 2014. To this end, we deal with three sectors: waste disposal, materials recycling services, and WDMRS sectors. More specifically, the production-inducing effect, value-added creation effect, and employment-inducing effect of the WDMRS sector are investigated based on demand-driven model. The supply shortage effect and the price pervasive effect are also examined employing supply-driven model and Leontief price model, respectively. The results show that the production or investment of 1.0 won in the WDMRS sector induces the production of 1.9324 won and the value-added of 0.7217 won in the national economy. Moreover, the production or investment of 1.0 billion won, supply shortage of 1.0 won, and a price increase of 10.0% in the WDMRS sector touch off the employment of 15.2462 persons, production loss of 2.0589 won, and an increases in overall price level by 0.0699%, respectively. This quantitative information can be usefully utilized inassessment of the WDMRS sector-related investment and policy.
        62.
        2015.01 KCI 등재 서비스 종료(열람 제한)
        Food waste, a putrescible form of waste, comprised of 30% of the total municipal solid waste stream in Daejeon Metropolitan City (DMC) in 2012. Proper management of food waste is a challenging task for local government. This study was conducted to determine material flows when treated food waste in various recycling facilities. Material flows in the recycling processes were collected by site surveys, field trips and discussion with operators and governmental employees. Material flow analysis (MFA) was conducted to quantify the flow of food waste from generation to disposal for the year 2012. MFA along with its mass transfer coefficients were determined based on the inputs, outputs and waste fluxes. According to the mass transfer coefficient results, treatment efficiency for the dry and wet feed manufacturing facility was found to be higher than other treatment facilities. Water consumption was higher for the composting site, resulting in large volume of wastewater (mass transfer coefficient 1.539). While large amounts of screening materials such as plastic, chopsticks, aluminum foils, and bottle caps were generated at the composting site, mass transfer coefficients (0.312) at the dry and wet feed facility were relatively high, implying effective treatment of food waste occurring. The results of this study help to facilitate waste management policy decision-makers in developing effective food waste management techniques in DMC.
        63.
        2014.07 KCI 등재 서비스 종료(열람 제한)
        This study was performed to prediction of generation and estimation of recycling value on waste artificial turf. The artificial turf consist of a different components by playground type, and combined of plastic, silica, and rubber materials. The weight per unit area of artificial turf is about 67.5% of the silica that is the highest, and infill rubber powder, pile, backing in order. As the result of investigation on artificial turf installation area from 2003 to 2012, the school playground is the largest portion because the development business plan of variety school grounds by government. And installed artificial turf will be discharge as the end of lifespan from 2011 to 2020. As the results of generation prediction by trend analysis, logarithmic function was estimated the most optimum method among the trend analysis. If 86.9% is recycled by Case II, the valuable materials of waste artificial turf was estimated that an annual average of about 2,990 tons of pile, about 2,177 tons of backing, about 52,803 tons of quartz sand, and about 20,241 tons of infill rubber powder in 2021 ~ 2040, respectively. It was evaluated to efficient recycling method of waste artificial turf that separated into the fabric and infill materials through first screening, and then infill materials separated into the silica and rubber powder through second screening.
        64.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        Global increase in the demand for the new Electrical and Electronic Equipment (EEE) results in the rapid increase of waste electrical and electronic equipment (WEEE) (or electronic waste). Significant efforts on developing diverse WEEE recycling policy and programs such as extended producer responsibility (EPR), WEEE directive, and the restriction of the use of hazardous substances (RoHS) directive are being made by many developed nations. This study focuses on determining priority among proposed WEEE recycling policy research projects by a number of experts from academia, institutions and recycling industry using quality function deployment (QFD) method to better manage and recycle WEEE in Korea. In order to develop effective WEEE recycling policy, a total of 12 different WEEE recycling policy research projects were proposed by a total of 11 experts related WEEE recycling. Reliability and validity evaluation of the proposed projects were conducted, along with SPSS statistical software. By using the QFD method, a survey regarding potential problems, suggestions, and difficulties at several WEEE recycling facilities were conducted and evaluated. Evaluation of the proposed projects was made by house of quality (HOQ). In this study, proposed research projects with higher importance index include WEEE collection system, development of WEEE recycling guideline, and establishment of WEEE generation/collection/recycling national database. The QFD method employed in this study can be effectively used as a decision-making process tool in WEEE recycling policy and road map.
        65.
        2014.04 KCI 등재 서비스 종료(열람 제한)
        This paper presents the estimation of actual recyclable amounts and the evaluation of waste oil recycling processes atrecycling facilities using material flow analysis (MFA). The estimation of actual recycling rates through the processes ofwaste lubricating oils is a very important subject not only in the point of view oil recycling efficiency by energy conversionprocesses but also in the perspective of the recycling technology level. In this study, the recycling processes and recyclingrates of waste lubricating oil recycling facilities were evaluated by using a MFA approach, a total of 10 site visits anda total of 30 site questionnaires in Korea. The MFA methodology based on mass balance approach applied to identifythe inputs and outputs of waste oils during the recycling processes at waste oil recycling facilities. It is necessary todetermine the composition and flows of the input materials to be recycled and foreign substances in a waste recyclingfacility. A complete understanding of the waste flows in the processes along with the site visit and data surveys for therecycling facilities was required to develop a material flow for the processes and determine the process yield by differenttreatment methods (chemical distillation, vacuum distillation and high temperature pyrolysis). The results show that onaverage the process yields for chemical distillation, vacuum distillation, and high temperature pyrolysis were 89.9±7.7%,77.9±16.1%, and 57.9±9.3%, respectively. During the chemical distillation method, water in waste oils was a majorfraction (>50%), while the vacuum distillation method resulted oil large amounts of oil sludge produced during therecycling process. The process yields for different treatment methods depended upon several factors including the qualityof incoming waste oils, the type and operating conditions of recycling processes that are applied to. Based on the materialflow analysis in this study, the actual recycled amount of waste oil was estimated to be approximately 260,809 ton in 2011.
        66.
        2014.01 KCI 등재 서비스 종료(열람 제한)
        Styela clava tunic is generated in large amounts as a waste from S. clava processing plants and causes environmental problem. Although biological activities of S. clava were reported by many investigators, study on S. clava tunic was little. In this study, therefore, tyrosinase inhibition and antioxidative activities of extracts from S. clava tunic using different solvent were investigated for recycling of the fishery waste. Among extraction methods tested, autoclaved extraction (25.7%) and hot water extraction (18.2%) appeared to be effective for extraction. The highest total phenolic content was 46.6 mg/g in autoclaved extract while the highest flavonoid content was 23.0 mg/g in chloroform extract. All extracts possessed tyrosinase inhibition activity and the inhibition activity was concentration-dependent. Inhibition concentration (IC50) against tyrosinase activity was 0.36×104 mg/ml in ethanol extract, 0.11×103 mg/ml in acetone extract and 0.27 mg/ml in n-butanol extract. Among extracts tested, hot water and autoclaved extracts displayed higher antioxidative activity than organic solvent extracts. Therefore, our data suggest that extract from S. clava tunic may potential candidate for cosmetic product with whitening effect and medicine for diseases caused by various oxidative stresses.
        67.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        This research was performed to evaluate the recycling characteristics by physico-chemical analysis of the wasted andthe reclaimed rubbers. Two types of the powdered and the reclaimed rubbers were sampled and analyzed. Pb was detectedin the range of 2.55~194.00mg/kg for the powdered rubber product, of which some exceeded the rubber standard criteria(90mg/kg), while it was 0.05~50.80mg/kg for the reclaimed rubber. Zn showed the highest concentration of heavymetals in the rubber products, comparing to the other heavy metals. It ranged from 9,750mg/kg to 27,900mg/kg, and388mg/kg to 17,450mg/kg for the powdered and the reclaimed rubber products, respectively. Total PAHs concentrationsof the powdered and the reclaimed rubber products exceeded greatly the rubber standard criteria (10mg/kg) as221.7~18,842.8mg/kg and not-detected~14,248.0mg/kg, respectively. Therefore, it was concluded that the managementplan and environmental criteria should be prepared for the recycled rubber product, considering the concentrations ofhazardous compounds such as Pb, Zn, and PAHs.
        68.
        2013.11 서비스 종료(열람 제한)
        This is aim to use and recycle the wasted biogas from the dispose process of the food wasted facility in Dae-Gu. Furthermore, the virtuous biogas is to be supplied for the Industrial Complex as energy resource. It is to develop the system for Pre-treatment and High-efficiency of the wasted biogas that includes low concentration and impurities. The Pre-treatment is to remove Siloxan, Hydrogen sulfide, Carbon dioxide, Oxygen and etc. which might influence to end-users in negative way. The High-efficiency system is to remove moisture in Biogas and increase the purity for keeping the constant concentration Methane for useful resource with measuring the portion and density in real time. It shows that constant above 60% Methane gas is possibly to be supplied to end-users as a alternative energy resource rather than using LNG, LPG and etc. for their own boilers system. It is expected that there are Environmental, Economical and Social effects with establishing optimum network for the reuse of Biogas. Environmental positive effects are to reduce the Global Warming Potential, use fossil fuel and Green-house gases. Economically it will bring down the production cost of end-users by using the pre-treated biogas. Furthermore, the alternative energy resource is to be secured and New R&D Study might be applied with FuelCell Power Plant, Hydregen Station and Hydrogen Reforming in social effects.
        69.
        2013.07 KCI 등재 서비스 종료(열람 제한)
        Ceramic welding backing material is a mullite-cordierite composite that is currently being used for welding processes in plant and shipbuilding. It is the optimal material for welding processes thanks to its extremely low thermal expansion coefficient and strong resilience against high temperature. However, due to the pollutants from welding such as iron and carbon, the entire amount of ceramic welding backing material is being land-filled after a single-time use. In this study, ceramic welding backing material was mixed with clay and kaolin to be used as a new ceramic body. A composition with 20 ~ 50% of ceramic welding backing material showed sufficient plasticity, and when fired at 1,250oC, it was deemed available for ceramic block and others with the porosity of 2.27 ~ 5.94%, water absorption ratio of 0.99 ~ 3.96% and bending strength of 720 ~ 810 kgf/cm2. In addition, color ceramic body, which was made from a waste welding backing material, of which iron was partially removed, added with 3wt% of high temperature pigment and fired at 1,250oC, displayed the unique color of the pigment, meaning that waste welding backing material could be used for ceramic bodies of a variety of colors.
        70.
        2013.03 KCI 등재 서비스 종료(열람 제한)
        This paper presents the actual recycling rates and recycling processes of waste plastic recycling facilities using material flow analysis. Determination of actual recycling rates through the processes of waste plastics is a very important subject not only from the point of plastic recycling efficiency energy conversion but also from the perspective of the recycling technology level. In this study, the recycling processes and recycling rates of waste plastic recycling facilities were evaluated by the MFA analysis based on 14 site visits and 25 questionnaires. The MFA methodology based on mass balance approach applied to identify the inputs and outputs of recyclable plastic materials in the recycling processes at recycling facilities. It is necessary to determine the composition and flows of the input materials to be recycled in a recycling facility. A complete understanding of the waste flows in the processes along with the site visit and data surveys for the recycling facilities was required to develop a material flow for the processes and determine the actual recycling rate. The results show that the average actual recycling rates for the recycling facilities by the site visit and the questionnaire was found to be approximately 87.5 ± 7.1% and 84.3 ± 14.5%, respectively. The recycling rates depended upon several factors including the quality of incoming waste plastics, the type and operating conditions of recycling processes, and the type of final products. According to the national statistics, the recycling rate of waste plastics was about 53.7%, while the actual recycling rate at national level was estimated to be approximately 45.1% by considering the recycling performance evaluated as well as the type of recycling process applied. The results of MFA for the recycling processes served as a tool to evaluate the performance of recycling efficiency with regard to the composition of the products during recycling. They may also support the development of the strategy of improvement of recycling processes to maximize resource recovery out of the waste plastic materials.
        71.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        This research was performed to evaluate the physicochemical characteristics of waste oil, waste solvent, and waste paint as waste derived fuel (WDF) feeding materials and WDF. Low heating values (LHVs) were in the ranges of 8,313.8 ~ 10,989.5 kcal/kg for waste oil, 4,109.1 ~ 9,890.6 kcal/kg for waste solvent, 5,733.7 ~ 8,051.0 kcal/kg for waste paint, and 5,184.2 ~ 10,679.0 kcal/kg for WDF. Sulfur contents showed 0.010 ~ 1.900% for waste oil, 0.000 ~ 0.073% for waste solvent, 0.004 ~ 0.581% for waste paint, and 0.001 ~ 0.700%, respectively. Chloride contents showed the ranges of 2 ~ 4,870 mg/kg for waste oil, 0 ~ 12,900 mg/kg for waste solvent, 0 ~ 10,700 mg/kg for waste paint, and 'not detected' ~ 4,070 mg/kg for WDF. Cd, As, and Hg were detected minimally in a few sample only. Other heavy metals showed below standard permission value for WDF. Feeding materials for WDF showed greatly different characteristics within even same sorts of wastes. And, as results of LHV, S, Cl, and heavy metal contents, WDF samples investigated in this research satisfied the standard permission value for WDF.
        72.
        2012.10 KCI 등재 서비스 종료(열람 제한)
        Batch cultivations were performed to evaluate the influences of the initial pH condition on mesophilic and thermophilic acidogenic fermentation with food waste recycling wastewater. In both conditions of mesophilic and thermophilic fermentation, TVFAs production rates were maximized at the initial pH 7 condition as 0.15 and 0.23 g TVFAs/L·hr, respectively. And pH was also maintained stably between 6 and 7 during 72hr acidogenic cultivation at both conditions. However, predominant VFA components were different according to reaction temperature conditions. In mesophilic condition, propionic acid which has low conversion efficiency to methane was accumulated up to 1,348 mg/L while acetic and butyric acid were predominant in thermophilic condition. Therefore, thermophilic acidogenic fermentation was superior for the effective VFAs production than mesophilic condition. From the DGGE analysis, the band patterns were different according to the initial pH conditions but the correlations of the each band were increased in similar pH conditions. These results mean that microbial communities were certainly affected by the initial pH condition. Consequently, the adjustment of the initial pH to neutral region and thermophilic operation are needed to enhance acidogenic fermentation of food waste recycling wastewater.
        73.
        2012.07 KCI 등재 서비스 종료(열람 제한)
        In this study, life cycle assesment (LCA) was conducted based on a functional unit of 1 ton of food waste recycling from collection and transportation to treatment processes such as feed production, composting, other recycling and incineration for 45 public food waste recycling plants. The Korean life cycle inventory (LCI) data were used for the main input material and energy. For the other input data, which could not be provided by the Korean LCI database, data of other countries were used from the database by Ecoinvent, and the strength of food wastewater for LCI DB was divided low and high concentration. In case of low strength of food wastewater, environmental impacts were suggested incineration, composting and feed production in the order, where collection and transportation were identified as the major influencing factors by contribution analysis and sensitive analysis. Contrary, in case of high strength of food wastewater, environmental impacts were suggested composting, feed production and incineration in the order, where treatment of food wastewater was identified as the major influencing factor. Therefore, discharge volume as well as concentration of food wastewater was found to be important parameter of the LCA.
        74.
        2012.03 KCI 등재 서비스 종료(열람 제한)
        South Korea has made remarkable achievements and gained many experiences on waste disposal and recycling, which help our country to develop cyclic economy and construct a harmonious society. This paper summarizes the policies, regulations and specific practices on waste disposal and recycling including industrial waste and household waste in South Korea so as to provide some references for the establishment of policies related to the waste recycling in our country.
        76.
        2011.01 KCI 등재 서비스 종료(열람 제한)
        In this research, food waste source reduction model for apartment was investigated. In spite of prohibition of direct landfill of food waste and continuous efforts made by government and local government, food waste production increases steadily. Recycling ratio of the food waste increases every year, but its products have many problems like low quality, stability, salt, odor etc. Household occupies 63.3% of whole food waste production and this is subject to be a key factor to control food waste. We surveyed S apartment in Kwangju city as a model case, in which administrative office and women's association adopted clean plate eating, separation of raw food waste and earth worm composting as a series of method for source reduction and recycling inside the apartment. With the help of residents' participation and practice, food waste production decreased 15.6% from 0.31 g/capita/day in 2007 to 0.26 g/capita/day in 2009 (domestic average 0.30 g/capita/day). Separation of raw food waste and its composting using earth worm were very effective, and were subject to resolve the problems of present food waste treatment technologies. And earth worm composting was very useful in environmental, economical, societal and educational aspects. Instead of economical incentive, educational programs about food value, environmental problem and critical method for food waste separation were more effective for promotion of source reduction. From the analyses on the process and success factors in this model, we could conclude that leader's role was one of the key factors for the settlement of source reduction, and that was to understand the seriousness of the food waste and to seek solution, to test techniques, and to practice by oneself. Furthermore, networking and collaboration among residents, local government, NGO and local press promoted residents' participation, and it was through various education and investigation. Finally, source reduction and self recycling model of food waste in the apartment, that applies separating raw food waste and earth worm composting based on the collaboration among residents, local government, NGO, and local press, should be disseminated, and environmental policy also should be changed to make it possible.
        77.
        2010.09 KCI 등재 서비스 종료(열람 제한)
        동원 NMC 선광장의 부유선별 프로세스를 유지하면서 광미여과액을 순환수로 활용하기 위한 pH 조절 연구를 수행하였다. 휘수연석(molybdenite)과 석영의 등전점(IEP)은 각각 pH 3 이하와 pH 2.7이었으며 안정화(분산)된 영역은 pH 5~10이었다. 순환수 현탁액의 경우, 잔류응집제의 의해 휘수연석의 제타전위는 pH 4 이상에서 -10 mV 이하로 감소하였다. pH 조절에 의한 부유선별 결과, 알칼리 영역에서 폴리머 사슬의 신장 및 확장, 칼슘 양이온(Ca2+)의 가교(ion bridge), 그리고 일부 무극성 폴리머/소수성 입자의 상호작용에 의한 응집 현상으로 부선효율이 급격히 저하되었다. 반면 약산성 영역(pH 5.5~6)은 수소이온에 의해 음이온성 폴리머가 중화되고 고분자 사슬의 기능이 약화됨에 따라 부선효율이 향상되었다. 조선부선 이후 정선부선의 최적조건인 pH 5.5, 포수제(kerosene) 20 g/t, 기포제(AF65) 50 g/t, 억제제(Na2SiO3) 300 g/t, 정선횟수 2회에서 Mo 품위와 회수율이 각각 52.7%와 90.1%인 최종 정광을 얻어 광미여과액을 분쇄-조선-정선 공정에 지속적으로 재활용할 수 있는 기술을 개발하였다.
        78.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        The aim of this study was to isolate chicken feather-degrading bacteria with high keratinolytic activity and to investigate cultural conditions affecting keratinolytic enzyme production by a selected isolate. A chicken feather-degrading bacterial strain CH3 was isolated from poultry wastes. Isolate CH3 degraded whole chicken feather completely within 3 days. On the basis of phenotypical and 16S rDNA studies, isolate CH3 was identified as Bacillus thuringiensis CH3. This strain is the first B. thuringiensis described as a feather degrader. The bacterium grew with an optimum at pH 8.0 and 37℃, where maximum keratinolytic activity was also observed. The composition of optimal medium for keratinolytic enzyme production was feather 0.1%, sucrose 0.7%, casein 0.3%, K2HPO4 0.03%, KH2PO4 0.04%, MgCl2 0.01% and NaCl 0.05%, respectively. The keratinolytic enzyme had a pH and temperature optima 9.0 and 45℃, respectively. The keratinolytic activity was inhibited ethylenediaminetetraacetic acid, phenylmethylsulfonyl fluoride, and metal ions like Hg2+, Cu2+ and Zn2+. The enzyme activated by Fe2+, dithiothreitol and 2-mercaptoethanol.
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