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        검색결과 114

        82.
        2006.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Ozone has become a significant pollutant not only outdoors but also indoors. The ozone emission test was conducted for the sum of forty five air cleaners selected in the online shops and department stores. Negative ion emission test was also conducted for the selected fifteen ones which had the function to generate negative ions. Filter-type and complex type air cleaners emitted ozone less than 0.05 ppm, the standard of indoor ozone emission of air cleaner. Wet type ones emitted no ozone. In the case of ionizer type, 66.7% in the nine ones emitted ozone about 1.4~10 times larger than 0.05ppm. Most of air cleaners used a pin corona discharge emitted large amount of ozone. Those which used carbon fiber emitted little ozone in spite of generating a lot of negative ions.
        4,200원
        86.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report a carbothermal reduction process for massive synthesis of monolithic WO phase from tungsten oxide in the presence of carbon source. Carbon black powder was used as a carbon source and added to WO by 40 weight percent. Bundles of WO rods were formed over the temperature range of 80 to 90. Pure WO bundles could be separated from the mixture of WO and residual carbon black powder. Field emission character of WO phase was determined using the extracted WO rods. Flat lamp fabricated from the WO rods showed the turn-on field of 9.3 V/
        4,000원
        91.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate for the natural methane emission inhibitor as a feed additive no adversely effect on rumen fermentation. Five different Control (Wheat barn (0.05 g), MRA(Methane Reduction Additive)-1 (Allium fistulosum L. (0.05 g)), MRA-2 (Sodium Lauryl Sulfate (0.025 g) +Wheat barn (0.025 g) mixed), MRA-3 (Sodium Dodecyl Sulfate (0.025 g) + Wheat barn (0.025 g) mixed), and MRA-4 (Allium fistulosum L. (0.02 g) + Tannic acid (0.02 g) + Wheat barn (0.01 g) mixed) contents were used to perform 3, 6, 9, 12, 24 and 48 h incubation for in vitro fermentation. Ruminal pH values were ranged within normal ruminal microbial fermentation. Dry matter digestibility was not significantly different across the treatments during the whole fermentation time. Also, the result of microbial growth had no adversely effect on during the whole fermentation time. At 24 h, methane emission was significantly lower (P<0.05) than all treatments except to MRA-1. Especially, MRA-4 carbon dioxide emission was significantly lower (P<0.05) than control at 9, 24 and 48 h incubation. In addition MRA-4 propionate concentration was significantly higher (P<0.05) than control at 24 h incubation. The result of RT-PCR Ciliate-associated methanogens were significantly lower (P<0.05) at MRA-1, MRA-3 and MRA-4 than control at 24 h incubation. Based on the present results, MRA-4 could be suggestible methane emission inhibitor as a natural feed additive.
        92.
        2018.05 서비스 종료(열람 제한)
        대도시에서 핵가족화의 이유 등으로 1인 단독세대 증가가 매우 빠르게 진행되고 있다. 그러나, 1인 단독세대에서 발생하는 생활쓰레기와 재활용쓰레기 발생량 등은 구체적으로 조사 및 연구가 부족한 현실이다. 결국, 1인 단독세대의 생활쓰레기 발생증가와 함께, 원룸 등 소규모 세대, 특히 1인 가구에 대한 재활용율 증가를 위해서는 우선적으로 정확한 배출흐름과 성상별 조사, 그리고 왜 재활용량이 저조한가에 대한 현장조사가 중요하다. 1인 가구 증가에 의해 배출되는 생활쓰레기의 성상 및 종류는 기존의 대규모 가족거주 주택에서 배출되는 쓰레기와는 많은 차이가 있을 것으로 예상된다. 이에, 1인 가구 증가에 따른 재활용품 분리배출량 증가를 위한 현장조사 및 DB화 작업이 매우 중요하다. 본 연구는 대전시 5개 기초자치단체별로 원룸 등 1인 가구에 대하여 생활쓰레기와 재활용품에 대한 배출실태에 관한 기초 연구이다. 이를 위해 이번 연구에서는 1인 가구에서 배출되는 종량제쓰레기와 재활용량에 대한 배출실태, 1인가구의 생활쓰레기 배출실태의 문제 및 의식 등을 조사하였다. 구체적으로는 1인 가구 학생을 대상으로 직접 자가배출량을 실측 및 기입하였다. 또한 1인 가구 학생을 대상으로 인터뷰조사를 실시하였다. 그리고 대전시 5개 기초 자치단체별로 1인가구로 판단되는 원룸 주변을 현장 방문 조사하여, 1인가구인 원룸가의 생활폐기물 배출실태 및 현황 모니터링하였다.
        93.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        By the end of 2012, the recycled proportion of domestic waste tires was 287,330 ton (93.9%) of the amount of waste tires discharged (305,877 ton). The waste tires have been reused for heat supply, material recycling and other purposes; the proportions are 50.1%, 20.7% and 23.1%, respectively. In the case of heat supply, waste tires are supplied to cement kiln (104,105 ton, 68%), RDF manufacture facilities (47,530 ton, 31%) and incinerators (1,923 ton, 1%). Recently, there has been an increase in the use of waste tires at power generation facilities as an auxiliary fuel. Thus, physico-chemical analysis, such as proximate analysis, elemental analysis and calorific value analysis have been carried out to evaluate potential of waste tires as an auxiliary fuel in Korea. The LHV (Lower Heating Value) of waste tires is approximately 20% higher than that of coal, at an average of 8,489 kcal/kg (7,684 ~ 10,040 kcal/kg). Meanwhile, the sulfur content is approximately 1.5wt. %, and balance of plant (e.g. pipe line, boiler tube, etc.) may be corroded by the sulfur. However, this can be prevented by construction and supplementation with refractories. In this study, TDF (Tire Derived Fuel) produced from waste tires was co-combusted with coal, and applied to the CFB (Circulating Fluidized Bed) boiler, a commercial plant of 100 tons/day in Korea. It was combined with coal, ranging from 0 to 20wt. %. In order to determine the effect on human health and the environment, gas emission such as dioxin, NOx, SOx and so on, were continuously analyzed and monitored as well as the oxygen and carbon monoxide levels to check operational issues.
        94.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        In South Korea, the “Waste Control Act” regulates the use and purpose of recycling waste and specifies recycling methods and specific standards. However, these processes requires a long time and large budget, because they need to be reviewed based on data specific to the type of waste involved. The use and purpose of recycling can be considered by its functional and environmental aspects. The functional aspect of recycling may vary widely, depending on product characteristics In contrast, environmental standards will have more points in common. Recycling standards that consider the environmental impact and characteristics of waste are not prepared specifically. Therefore, when a large amount of waste is recycled, or recycling standards are applied to a new type of waste, the methodology for review of its environmental characteristics can be controversial. This study is meant to recognize the necessity of recycling standards and to prepare environmental standards and new recycling purposes for waste related to recycling three types of gypsum waste (phospho, titan, desulfurization). Several companies were selected for this study. In the gypsum waste-generating company, gypsum waste samples were collected and analyzed for pH, heavy metal content, water content, hazardous substance content, etc. In addition, we attempted to obtain the company's opinions on waste recycling. We determined the hazardous materials found in these three types of gypsum waste, raised awareness of waste, and confirmed that industry waste can be efficiently recycled for new uses under the improved.
        95.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        Domestic industrial waste small-scale industrial incinerators produce less than 200 kg/hr; this study chose 13 of the 249 potential facilities. The target average emissions for air pollutants resulting from the facilities were SOx 13.56 ppm, NOx 82.74 ppm, NH3 19.95 ppm, HCl 54.33 ppm, HF 0.84 ppm, Hg N.D, As 0.1 ppm, H2S N.D. Dust and heavy metal analysis results for the facilities revealed Dust 32.51 mg/Sm3, Cd 0.04 mg/Sm3, Pb 0.20 mg/Sm3, Cr 0.08 mg/Sm3, and Cu 0.03 mg/Sm3. Combustion indicators were O2 11.58% and CO 271.20 ppm. Average PCDDs/DFs were 17.87 ng ITEQ/ ton. The target facilities were equipped with anti-pollution facilities. However, some items were found to exceed the emission standards. These results are even equipped with control facilities due to manual limitation actions of the management personnel. Therefore, it is determined that the emission control of contaminants is difficult.
        96.
        2017.05 서비스 종료(열람 제한)
        나노기술의 발달로 의료, 환경, 자동차, 건축 등 다양한 분야에서 공업용나노물질(ENMs, Engineered Nano Materials)의 사용이 증가하였으며, 이에 따라 제품의 제조, 운반, 저장, 사용, 폐기로 하・폐수처리시설, 소각시설에서 나노물질을 함유한 폐기물이 발생하고 있다. 특히 ENMs은 내부 또는 외부차원의 크기가 1∼100 nm로 동일 성분의 큰 입자와 다른 물리화학적 특성을 가지고 있다. 또한 이러한 특성을 가진 나노물질이 폐기물처리 시설로 유입되어 처리될 때 기존 폐기물과 다른 특성을 나타낼 수 있으며 이에 대한 연구는 거의 없는 실정이다. 따라서 본 연구에서는 나노물질의 종류, 사용량, 물리화학적 특성 그리고 배출형태 등을 참고하여 산화아연, 이산화티타늄, 탄소나노튜브, 은나노를 선정하였다. 조사대상 시료는 하・폐수처리시설 슬러지, 소각시설 비산재, 바닥재, 매립지 침출수와 슬러지 등 35종의 시료를 채취하였다. 시료 분석방법은 폐기물공정시험방법, 토양오염공정시험방법 등을 참고하여 납, 카드뮴, 티타늄 등 중금속 16종을 분석하였다. 아울러 입도분석, TEM(투과전자현미경), XRD, XRF 측정장비를 이용하여 시료특성을 조사하였다. 연구 결과 제조시설에서 발생된 페기물은 ENMs의 물리화학적 특성을 가지고 있었다. 그러나 환경으로 배출된 폐기물을 처리하는 시설에서 폐기물의 물리화학적 배출특성을 조사하였으나 표준화된 공업용 나노물질분석 방법, 나노물질의 입도크기에 따른 환경오염물질과 결합 반은 또는 소각시설에서 고온에 의한 변형 등 여러 가지 영향인자로 폐기물 중 나노물질의 존재 유무 및 형태를 명확하게 확인할 수 없었다.
        97.
        2017.04 KCI 등재 서비스 종료(열람 제한)
        In this study, gasification experiments were conducted using high calorific waste by measuring flue gas and gaseous pollutant composition. The feedstock used in this experiment was collected from industrial wastes and had a heating value more than 5,000 kcal/kg as well as low moisture and ash contents. Experiments were conducted at 1,200°C temperature by changing equivalent ratios (ERs) to find out an optimum condition for syngas production. Results showed that at ER 0.3, the highest syngas composition (around 81%) was obtained in flue gas. In this study, gas pollutant was sampled in cold absorbent by following Korean air pollutant standard sampling method. Later, sampled solutions were analyzed by IC (Ion Chromatography) to find out gaseous pollutant concentration. Usually, after gas cleanup system, all of the gaseous pollutants are removed by wet scrubber and catalyst reactor. However, in this study, due to gaseous pollutants removed by wet scrubber, the removal efficiency of gaseous pollutants showed lower performance compared with other catalyst clean up system. Thus, it is advisable to install a cleaning unit to deal with tar and soot.
        98.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to evaluate the emission characteristics of air pollutants from incineration facilities in Jeollanam-do. We selected 8 incineration facilities depend on type and the 19 items such as dust etc. were measured at the measurement hole for emission gas from air contamination control units. The range of emission concentrations for dust was 2.8 ~ 20.9 mg/Sm3 less than permissible air discharge standards. The results of 10 gaseous contaminants such as SOx was less than permissible air discharge standards. The range of emission concentrations for NOx was 13.4 ~ 120.0 ppm, less than permissible air discharge standards. As G facility was 112.4 ppm, 120.0 ppm, it exceeded emission standard (100 ppm) twice. The range of emission concentrations for HCl was ND ~ 85.300 ppm, B Facilitiy exceeded emission standard (20 ppm) as 85.300 ppm. The range of emission concentrations for NH3 was ND ~ 76.333 ppm, A, D, H Facility exceeded emission standard (30 ppm). The concentration of each facility was 42.416 ppm, 62.930 ppm, 76.333 ppm. The results of heavy metals (5 items) showed within emission standards. G facility is operating in condition that input of urea is 100 L/day. If input of urea were changed to 50 ~ 75 L/day, the operating cost of air pollution prevention facility can be reduced by 25% ~ 50%. In this study, the correlation between urea input and nitrogen oxides was statistically significant, but the correlation between urea input and ammonia showed insignificantly. Our research attempts to evaluate the emission characteristics of air pollutants from incineration facilities and to institute a reduction plan, an effective management of incinerators.
        99.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        There is legal uncertainty and ambiguity with regards to the classification and disposal of sludge generated from glassetching process. Moreover, secondary effect on the environment such as corrosion of landfill construction by the sludgeproduced in glass etching process was observed in waste landfill site. As part of response to the parliament’s request forthe relevant data and local media coverage, exhaustive investigation of glass etching process was required. Accordingly,we conducted an exhaustive investigation of 8 glass etching manufacturers. Glass etching business is one of the businessesthat have seen rapid growth since 2010 with the development of semiconductor and electronics industry, and glass etchingproducers are mostly located in Gumi, Cheongju, Sejong, Gongju, and Cheonan cities. In this study, we investigated theharmful effects of wastes generated from the glass etching process, how those wastes are classified and treated, problemsarose from the process, and secondary effects on the environment observed in waste landfill site. The study found thatcyanide, lead, mercury, trichloroethene, and perchloroethene were not detected in the sludge produced from glass etchingprocess, and hexavalent chromium, copper, and arsenic were either not detected or reported at very low level, which wasbelow the threshold concentration level of designated waste. In contrast, pH of sludge produced from glass etching processwas between 1.7 and 2.3, pH of hydrofluoric acid used for glass etching showed acidic value of 1.5, which suggests thatthe classification system of such hazardous substance requires reconsideration.
        100.
        2015.07 KCI 등재 서비스 종료(열람 제한)
        Waste electrical and electronic equipment (WEEE) has been received much attention recently due to rapid changes in materials and shorter replacement of consumer products. Most of WEEEs are collected and recycled at the designated recycling centers in Korea, and final residues after recycling, sorting and shredding them to separate valuable and recyclable parts in series are left as forms of shredded plastic mixtures, which would be a problem to be resolved. By further plastics separation the polyurethane foams are mostly remained and becomes waste to be treated by appropriate methods. Gasification to produce syngas and incineration to recover energy for such polyurethane foam waste could be utilized instead landfill presently treated. In this study the experiment was conducted to evaluate such performance characteristics of thermal processes. Pelletized solid refuse fuel (SRF) was fabricated to feed into the test furnace even though it was light with low density. Thermogravimetric analysis, proximate analysis and higher heating value were made. During gasification and incineration, gas composition with gaseous pollutants were measured. Due to nitrogen content in polyurethane, nitrogen containing gaseous substances such as NH3 and HCN were observed with varying equivalent air ratios (ERs). The assessment of polyurethane waste foam to energy using incineration and gasification was made with finding out the optimal condition of air injection to emit less pollutants in both operations. Produced syngas could be utilized as energy fuels by lowering pollutants emission.
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