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        검색결과 13

        2.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 주남저수지의 수질, 퇴적물, 저서성 무척추대형동물, 어류, 수생식물을 조사 및 분석함으로서 수생태계의 보전과 복원을 위한 기초자료 제공에 그 목적이 있다. 수질분석 결과, 수소이온농도(pH)는 8.2~8.4, 화학적 산소요구량(COD)은 6.0~7.5mg/L, 부유물질량(SS)은 10.0~10.3mg/L, 용존산소량(DO)은 8.3~11.5mg/L, 총인량(T-P)은 0.1mg/L, 총질소량(T-N)은 1.2~1.3mg/L로 나타났다. 퇴적물의 경우 Cd(카드뮴)는 0.47~0.52mg/kg, Cu(구리)는 7.08~7.43 mg/kg, As(비소)는 0.22~0.32mg/kg, Hg(수은)는 0.02~0.03mg/kg, Pb(납)는 6.20~7.45mg/kg, Ni(니켈)는 32.80~39.70mg/kg, F(불소)는 513.0~543.0mg/kg, Zn(아연)은 137.0~140.0mg/kg으로 나타났으며, Cr6+(6가크롬)은 검출되지 않았다. 저서성 대형무척추동물은 3문 5강 9목 26과 33속 39종 432개체가 있는 것으로 확인되었으며, 저서성 대형무척추동물의 생태점수(ESB)는 25로 나타났다. 어류는 8과 14종으로 나타났으며, 생태계교란야생동식물은 큰입배스와 파랑볼우럭 등 2분류군이었다. 수생식물은 28과 42속 56종 1아종 6변종 등 총 63분류군으로 확인되었으며, 정수식물은 38분류군(60.3%), 부엽식물은 5분류군(7.9%), 부유식물 및 침수식물은 각 10분류군(15.9%)로 나타났다.
        4,500원
        3.
        2015.01 KCI 등재 서비스 종료(열람 제한)
        Waste heavy oil sludge is considered oil waste that can be utilized as a renewable energy source. Although it has high calorific values, it should be treated as a designated waste. During the recycling process of construction and demolition wastes or the trimming process of woods, a lot of sawdust is produced. In this study, the feasibility of BOF (biomass and waste heavy oil sludge fuel) as a source of renewable energy was estimated. To investigate its combustion characteristics, a lab scale batch type combustion reactor was used, and temperature fluctuation and the flue gas composition were measured for various experimental conditions. The results could be summarized as follows: The solid fuel pellets manufactured from waste heavy oil sludge and sawdust had C 50.21 ~ 54.77%, H 10.25 ~ 12.66%, O 25.84 ~ 34.83%, N 1.01 ~ 1.04%, S 1.03 ~ 1.07%. Their lower heating values ranged from 4,780 kg/kcal to 5,530 kg/kcal. The density of the solid fuel pellets was increased from 0.63 g/cm3 to 0.85 g/cm3 with increasing the mixing ratio of waste heavy oil sludge. The maximum CO2 concentration in the flue gas was increased with increasing waste heavy oil sludge content in BOF. SO2 concentration in the flue gas was showed a tendency such as the highest CO2 concentration in the flue gas. With increasing waste heavy oil sludge content in BOF, the combustion time became rather shorter although the increase of the CO2 concentration in the flue gas was delayed. Because the carbon conversion rate showed small difference with increasing the mixing ratio of waste heavy oil sludge in BOF, BOF with the mixing ratio of waste heavy oil sludge of 30% was effective for combustion. With increasing the mixing ratio of waste heavy oil sludge in BOF, activation energy and the amount of total CO emissions were increased, while activation energy was decreased with increasing the air/fuel ratio. Therefore, the optimal air/fuel ratio for the combustion of BOF was 1.5.
        4.
        2015.01 KCI 등재 서비스 종료(열람 제한)
        Waste heavy oil sludge is considered oil waste that can be utilized as a renewable energy source. In this study, an attempt has been made to convert the mixtures of waste heavy oil sludge and sawdust into solid biomass fuels. The solid fuel pellets from waste heavy oil sludge and sawdust could be manufactured only with a press type pelletizer. The mixing ratios of waste heavy oil sludge and sawdust capable of manufacturing a solid fuel pellet were 30 : 70, 40 : 60 and 50 : 50. Ultimate analysis result revealed that these mixtures had C 50.21 ~ 54.77%, H 10.25 ~ 12.66%, O 25.84 ~ 34.83%, N 1.01 ~ 1.04%, S 1.03 ~ 1.07%. With increasing the mixing ratio of waste heavy oil sludge, the carbon and hydrogen content in solid fuel pellets were increased, while the oxygen content was decreased. But the nitrogen and sulfur content in solid fuel pellets did not show much difference. Their lower heating values ranged from 4,780 kg/kcal to 5,530 kg/kcal. The density of the solid fuel pellets was increased from 0.63 g/cm3 to 0.85 g/cm3 with increasing the mixing ratio of waste heavy oil sludge and the collapse of the solid fuel pellets occurred at a moisture content of 21%. As the mixing ratio of waste heavy oil sludge in the solid fuel pellets was increased, the reaction of thermal cracking became faster. It was also observed that the solid fuel pellets were thermally decomposed in two steps and their DTG curves were simpler with increasing the mixing ratio of waste heavy oil sludge. The activation energy and the pre-exponential factor of the solid fuel pellets ranged from 18.90 kcal/mol to 21.36 kcal/mol and from 201 l/sec to 8,793 l/sec, respectively. They were increased with increasing the mixing ratio of waste heavy oil sludge.
        5.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        Waste oil sludge was generated from waste oil purification process, oil bunker, or the ocean plant. Although it has high calorific values, it should be treated as a designated waste. During the recycling process of construction and demolition wastes or the trimming process of woods, a lot of sawdust is produced. In this study, the feasibility of BOF (biomass and waste oil sludge Fuel) as a source of renewable energy was estimated. To estimate combustion characteristics, a lab scale batch type combustion reactor was used and temperature fluctuation and the flue gas composition were measured for various experimental conditions. The results could be summarized as follows: the maximum CO2 concentration in the flue gas was increased with increasing waste oil sludge content in BOF. SO2 concentration in the flue gas was showed a tendency such as the highest CO2 concentration in the flue gas. With increasing waste oil sludge content in BOF, the combustion time was rather shorter although the increase of the CO2 concentration in the flue gas was delayed. Because the carbon conversion rate showed small difference with increasing the mixing ratio of waste oil sludge in BOF, BOF with the mixing ratio of waste oil sludge of 40% was effective for combustion. With decreasing the air/fuel ratio and the mixing ratio of waste oil sludge in BOF, activation energy and frequency factor were increased. The optimal air/fuel ratio for the combustion of BOF was 1.5.
        6.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        The large amount of waste oil sludge was generated from waste oil purification process, oil bunker, or the ocean plant. Although it has high calorific values, it should be treated as a designated waste. During the recycling process of construction and demolition wastes or the trimming process of woods, a lot of sawdust is produced. In this study, the feasibility of BOF (biomass and waste oil sludge fuel) as a renewable energy source was estimated. For manufacturing a BOF, a press type pelletizing was better than an extruder type and also 40 ~ 60% of mixing ratio in waste oil sludge was appropriate to produce a pellet. The pellet was 13 mm in diameter and 20 mm in length. There was no fixed carbon in waste oil sludge, and its carbon content and higher heating value were 63.90% and 9,110 kcal/kg, respectively. With an increse of mixing ratio of sawdust, the carbon content and heating value of the BOF were dropped, but fixed carbon content was increased. The heating value of BOF was in the range of 6,400 ~ 7,970 kcal/kg at the mixing ratio of 40 ~ 60% in waste oil sludge. It means that the BOF can be classified as the 1stgrade solid fuel. In TGA experiment carried out at heating rate of 10oC/min and under nitrogen atmosphere, thermal decomposition of sawdust was occurred in two steps, but waste oil sludge was destructed in one step. The initiated cracking temperature of sawdust and waste oil sludge was 300 and 280oC in respective and after 450oC the thermal decomposition process of sawdust was slowly progressed by 800oC in contrast to waste oil sludge. Thermal decomposition of waste oil sludge was finished around 600oC. It can be considered that this difference is due to the fixed carbon content. Thermal decomposition pattern for the pellet of mixing ratio over 50% in waste oil sludge was similar to that for waste oil sludge and thermal cracking was occurred between 300 and 350oC. As the mixing ratio of waste oil sludge in the pellet increased, the reaction of thermal cracking became fast.
        7.
        2014.11 서비스 종료(열람 제한)
        고형연료의 제조 가능성을 살펴보기 위해 사용된 폐오일슬러지는 총 3종류이다. 3종류의 발생원 중 첫 번째 발생원이 주유소, 버스나 지하철차량 정비공장, 철공소, 기계공장, 제강압연공장 그리고 산업기계공장 등에서 발생하는 윤활유계통이다. 두 번째 발생원이 자동차정비공장, 기계공장, 제강・압연공장, 버스나 지하철차량 정비공장, 출판인쇄 그리고 고무제품 공장 등에서 발생하는 세정유 계통이다. 마지막으로 오일저장탱크에서 발생되는 중유계통이며, 앞서 언급한 3종류의 폐오일슬러지와 톱밥의 혼합비율별로 고형연료를 제조하였다. 압출식 제조 장치에서는 폐오일슬러지와 톱밥의 혼합은 충분히 이루어졌지만, 고형연료의 형태유지는 이루어지지 않았다. 압밀식 제조 장치에서는 고형연료 내 폐오일슬러지 함유량이 20~60%일 때 폐오일슬러지 함수량 5, 12, 18%에서 제조가 가능한 것으로 조사되었다. 또한 폐오일슬러지 내 수분함량으로 인해 고형연료의 형태유지 범위가 증가하는 것을 알 수 있었다. 고형연료 제조 시 폐오일슬러지의 함유량이 60% 이상이 될 때 폐오일슬러지가 톱밥에 잘 스며들지 않아 고형연료 제조가 어려운 것으로 나타났다. 따라서 본 실험의 분석범위는 폐오일슬러지 함유량이 30%, 40% 그리고 50%로 설정하였다. 중유계통의 폐오일슬러지의 특징으로는 인화점(60-90℃), 수분(0.5-10%), 회분(4-10%)인 것으로 조사되어진바 있다. 폐오일슬러지 내 함수량의 경우 2%미만의 낮은 범위에서는 연소에 문제가 없지만 함수량이 5%이상이 될 경우 연소가 불안정하게 된다. 따라서 본 실험에서는 폐오일슬러지 내 수분을 변수(1.5, 5, 10%)로 하여 본 실험에서는 오일저장탱크에서 발생되는 중유계통의 폐오일슬러지로 제조한 고형연료의 제조 특성을 살펴보았다.
        8.
        2014.11 서비스 종료(열람 제한)
        연소특성을 살펴보기 위하여, 1kg용량의 회분식 스토카 소각로를 제작하였으며, 소각로내의 온도분포와 화격자의 온도변화를 관찰하기 위하여 로 하부로부터 높이 180 mm와 450 mm지점에 K-type의 열전대를 장착하였고, 공기공급을 위해 로의 좌・우측 및 하부에 총 64개의 공기 nozzle을 설치하였으며, 2마력 용량의 콤퓨레샤(compressor) 2대를 이용해 로 내로 공기를 공급하였다. 연소 배가스 분석을 위하여 연소가스 냉각기와 시료 채취용 Champer를 소각로 후단부에 각각 설치하였다. 연소 배가스의 성분분석은 Champer에 연결된 배가스 분석기(GreenLine 9000, Eurotron, Italy)를 이용하여 측정하였다. 소각로의 초기온도는 850℃로 설정하였고, 공기비는 2.5로 설정한 후 연소계산을 이용해 연소에 필요한 공기량을 산출하였다. 또한 로내 시료투입시 외부공기의 유입으로 인한 로내온도 변화를 최대한 방지하기 위해 빠른 시간 내에 시료 50g을 스토커 위에 장착한 후 다시 문을 닫아서 7분간 연소실험을 수행하였다. 연소실험이 진행되는 동안 K-type 열전대를 이용하여 로내 온도와 화격자 상부의 온도를 측정하였으며, 연소로 인해 생성된 가스가 로내에서 충분히 혼합될 수 있도록 산정된 공기량을 기준으로 좌우와 하부에서 각각 30%와 70%의 공기가 유입되게끔 조절하였다. 운전 초기 고형연료의 투입과 함께 외부공기 유입으로 인해 로 내의 온도가 급격히 감소하였으며, 이후 시료가 연소되면서 약 50초가 경과하면 로 내 초기 설정온도보다 높은 화격자 상부의 연소온도가 감지되었다. 또한, 연소실험 중 최대온도가 감지되는 구간에서 배기가스의 산소농도가 최저치로 기록되어 연소가 가장 활발하게 진행되고 있음을 알 수 있었다. 배기가스 중의 최저산소농도는 시료투입 후 약 100초가 경과한 이후에 나타났고, 폐오일슬러지의 혼합비율이 감소할수록 로 내 최저산소농도가 나타나는 시점이 빨라졌다. 이는 폐오일슬러지의 양이 적어질수록 톱밥의 양이 증가하기 때문에 착화가 상대적으로 빨리 이루어지기 때문인 것으로 판단된다. 그리고 오일슬러지 함유량이 감소할수록 CO2 농도도 낮은 것으로 관찰되었는데 이는 폐오일슬러지 감소에 따른 C 함량의 감소에 의한 영향으로 사료된다. CO의 경우 휘발분과 고정탄소의 연소로 인한 2개의 peak가 나타나지 않았는데, 이는 폐오일슬러지의 높은 휘발분 함량으로 인해 1차 peak만 나타난 것으로 보인다. 그리고 고형연료의 폐오일슬러지 함유량이 증가하여도 CO 농도는 큰 변화를 보이지 않았다. 이것은 고형연료 내 C의 연소와 함께 발생되는 배기가스 중 CO의 재연소가 충분히 이루어지는 것으로 사료된다. NOx의 경우 고형연료의 폐오일슬러지 함유량에 상관없이 고형연료의 연소와 함께 발생하였다.
        9.
        2012.11 KCI 등재 서비스 종료(열람 제한)
        A biological assessments of fish community structure were carried out in the lower reach of Seomjin River from May 2009 to November 2010. The collected fish from the six surveyed sites were 63 species belonging to 24 families, and 10 orders. Although species was different depending on sites, the numbers of individuals were not shown significance on sites. Locational dominant species were different. For example, the dominant species on May were Zacco platypus at W-1, Zacco temminckii at W-2, Acanthogobius flavimanus at W-3 and W-4, and Leiognathus nuchalis at W-5 and W-6. There is no seasonal differences in species. Species diversity was the best up to 2.64 on May at W-1 from 1.33 on November at W-6. As a result of an analysis about environmental factors for the numbers of fish species and individuals in each surveyed sites, the most effective groups were DO, BOD, and COD. The proportional difference was high on May than November between transient and asymptotic projections for population size and population growth rate for simulations starting at the current or theoretical stage distribution.
        10.
        2009.07 KCI 등재 서비스 종료(열람 제한)
        In this study, which aims to estimate the volume of greenhouse gas emitted by road transportation vehicles in Changwon City, the emission rate was calculated on the basis of the actual traffic volume measured at major crossroads and compared with the results obtained from the methodology used to estimate the greenhouse gas emissions of road transportation provided in the IPCC 2006 GL guidelines (Tier 1, Tier 3). Analysis of the results of the comparison showed that the Tier 1 methodology, which was applied in the estimation of the rate of greenhouse gas emissions, carries a high probability of underestimation, while the Tier 3 methodology carries a relatively high probability of overestimation. Therefore, when considering the assignment of permissible rates of emission to local governments, the application of the methodology, i.e. whether one uses Tier 1 or Tier 3, may result in a large difference in the rate of allowable emissions. It is suggested that a method based on the actual volume of traffic would be the most reasonable one with regard to the development of a realistic plan.
        12.
        2008.05 KCI 등재 서비스 종료(열람 제한)
        5 public complaint areas against odor in Changwon Industrial Complex were selected and investigated to clear up the cause of the complaint. 16 companies operated in public complaint areas were visited and had a grip of their situation about odor generation and treatment. Two samples at it's site boundary of each company were taken to measure complex odor unit. Complex odor unit at the site boundary of investigated companies in the public complaint areas, for the most part, exceeded standard(odor unit 20) in industrial area. It was due to that this area was not designated as odor control region and that there are also many problems in current laws of Odor Protection Act, Air Quality Act and regional legislation. Accordingly, It will be necessary to revise the related legislation, to organize governance, to financially support the improvement of environmental facilities and to enforce guidance and the regulation rigidly for the odor emission reduction in Changwon Industrial Complex.
        13.
        1997.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to use oyster shell as media for biological wastewater treatment. The comparison between the removal efficiencies of the activated sludge and the submerged biofilm process with oyster shell media (5% of reactor volume) for domestic sewage treatment was made. The contaminant removal efficiencies of the submerged process were higher than that of the activated sludge process. And the removal efficiencies of the submerged biofilm process with oyster shell media of 10% and 18% were investigated at various loading rate. The removal efficiencies of 10% were higher than that of the 18% during the experimental period. The effluent concentration from the submerged biofilm process using oyster shell media was prediceted by the Stover-Kincannon model.