• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.1386-1391
• /
• 2007

The ballast gravels are often contaminated by various pollutants, like diesel fuel, lubricants, and heavy metals. Especially, the gravels near the switching are apt to be polluted by the lubricant. Because this lubricant can pollute the soil of track, the contaminated ballast gravels should be cleaned immediately. In this study, a physical desorption method was used to remove the oil contaminants from the surface of the ballast gravels. Thermosetting resin was used as a media for physical remediation of ballast gravels. The total petroleum hydrocarbon of the gravels was monitored over time. In addition, scanning electron microscopic images were obtained to observe the removal of the oily pollutants from the surface of the gravels.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2002년도 추계학술발표회
• /
• pp.370-373
• /
• 2002

위해성 평가(Risk assessment)는 지하수나 토양의 오염으로 인해 자연 환경과 사람에게 미칠수 있는 위해(risk)를 정량적으로 평가하는 방법이다. 이 평가를 바탕으로 대상지역의 오염도 저감 여부 및 목표를 설정할 수 있다. 본 연구에서는 유류로 오염된 부지를 대상으로 측정된 TPH(Total Petroleum Hydrocarbon)값에 근거하여 인체에 미칠 수 있는 위해((Risk)에 대한 정량적인 평가와 동시에 오염된 토양 및 지하수의 정화기준을 산정 하고자하였다. 그 결과 유류로 오염된 00지구에 대한 정화기술적용시의 최소성분감소비(CRF)를 산출하여 정화의 정도치와 정화목표농도를 산출하였다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2002년도 추계학술발표회
• /
• pp.310-314
• /
• 2002

To investigate the effect of on-site bioremediation in soil that have been contaminated by hydrocarbon fuel spills, petroleum-degrading bacteria isolated from soil around petroleum chemical industry and microbial agents were constructed. We investigated biopiles for on-site bioremediation of soil contaminated (5000 mg per kg) with bunker A fuel in five independent lab-scale experiments. Five biopile units constituting the following treatments: (1) control with no nutrients and microbial agents (2) microbial agent M plus nutrients (3) microbial agent C plus nutrients (4) only microbial agent C (5) control with only nutrients. The results were highly different one another. After 30 days in treatments with optimal condition, total petroleum hydrocarbons were reduced to below 10 mg per kg of soil at the biopile units mixed with microbial agents, but control biopile units show that were reduced from 1,105 to 2,588 mg per kg of soil. Our results show that microbial agents at on-site bioremediation of fuel-contaminated soil is highly effective.

• Preventive Nutrition and Food Science
• /
• 제15권2호
• /
• pp.147-151
• /
• 2010

The volatile aroma constituents of Atractylodes japonica rhizome were separated by steam distillation extraction method using a Clevenger-type apparatus, and analyzed by gas chromatography-mass spectrometry (GC/MS). The yield of the essential oil from Atractylodes japonica was 1.0% (v/w), and its color was pale yellow. Forty-five volatile flavor compounds, which make up 93.86% of the total peak area, were tentatively identified in the rhizome oil. The oil contained 32 hydrocarbons (79.19%) with sesquiterpene hydrocarbon predominating, 3 esters (12.46%), 4 alcohols (0.11%), 1 ketone (0.01%), 2 aldehydes (0.02%), and 3 miscellaneous compounds (2.07%).

• 대한기계학회논문집
• /
• 제8권3호
• /
• pp.210-216
• /
• 1984

본 연구에서는 이러한 화염의 구조를 자세히 파악하기 위하여, 화염의 온도분 포 및 가스농도분포 등을 비교적 정밀하게 측정하고 Shadow graph 등을 통하여, 선회 화염의 거시적인 구조적 특성을 알아보고 일산화질소, 탄화수소 및 일산화탄소 등의 생성특성을 규명함으로서 실제 버어너에서의 기하학적 변형에 따른 화염구조의 예측과 수치해석을 위한 기본 데이타를 얻고, 공해물질발생과 화염구조와의 상관관계를 제시 하는데 그 목적이 있다.

• Environmental Engineering Research
• /
• 제14권2호
• /
• pp.95-101
• /
• 2009

Natural gas is a promising alternative fuel of internal combustion engines. In this paper, the combustion and emission characteristics were investigated on a natural gas engine at two different fuel injection timings during the intake stroke. The results show that fuel injection timing affects combustion processes. The optimum spark timing (MBT) achieving the maximum indicated mean effective pressure (IMEP) is related to fuel injection timing and air fuel ratio. At MBT spark timing, late fuel injection timing delays ignition timing and prolongs combustion duration in most cases. But fuel injection timing has little effect on IMEP at fixed lambdas. The coefficient of variation (COV) of IMEP is dependent on air fuel ratio, throttle positions and fuel injection timings at MBT spark timing. The COV of IMEP increases with lambda in most cases. Late fuel injection timings can reduce the COV of IMEP at part loads. Moreover, engine-out CO and total hydrocarbon (THC) emissions can be reduced at late fuel injection timing.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2000년도 추계학술대회
• /
• pp.177-181
• /
• 2000

A lab-scale slurry reactor was developed for the treatment of contaminated sediments with polycyclic aromatic hydrocarbons (naphthalene, phenanthrene). In this system, range from 85 to 95% of PAHs with 2~3 rings were degraded within 11 days. Higher naphthalene degradation(94.05%) over phenanthrene degradation(87.07%) was probably due its higher solubility. Both compounds were not detected in aqueous phase after 7days and only 26.8% of naphthalene and 49.1% of phenanthrene were biodegraded. Removal TPH(Total Petroleum Hydrocarbon) concentration in solid after 11 days of treatment was 46%.

• 대한화학회지
• /
• 제7권2호
• /
• pp.122-127
• /
• 1963

Pyrolysis fo polyethylene and polypropylene has been studied in order to clarify the mechanism of chain scission and effect of oxygen on degradation. Rate of weight decrease was measured under nitrogen and air atmosphere at constant temperature for the samples of high density polyethylene, low density polyethylene and isotactic polypropylene, and then gaseous hydrocarbons produced from pyrolysis were analysed by gas chromatography. Although there is little substantial difference between composition of hydrocarbon gases from pyrolysis of high density polyethylene and low density polyethylene except some difference in quantity of total gas produced, gas composition from polypropylene pyrolysis differs from that of polyethylene pyrolysis. Gases from pyrolysis under air contain much more unsaturated hydrocarbons than those from pyrolysis under inert gas.

• 한국대기환경학회지
• /
• 제13권3호
• /
• pp.215-220
• /
• 1997

CNG dual fuel engine for heavy duty diesel engine developed by AFS International in Canada has been equipped to a Korean city bus engine and tested to compare the engine performance and the emission characteristics with the existing diesel fueled engine. Also the dual-fuel engine was applied to the city bus for road test. The results are summarized as follows. Performance optimization has been carried out to have engine power equivalent to or better than the diesel fueled engine. Smoke is decreased by 85% by Korean smoke 3 mode test. By 13 mode test CO is increased by 453% and THC is increased by 2, 086%. NOx is decreased by 7% in laboratory. D-13 test mode was changed in 1996 Korean regulation. Even though THC is increased very much, it's not too serious problem since CO and HC emission of diesel engine is very little compared to gasoline engine and more than 75% of THC is CH$_4$. But the reduction technologies of CO and HC has to be considered.

• Environmental Engineering Research
• /
• 제24권4호
• /
• pp.591-599
• /
• 2019

To convert sewage sludge to energy, drying-gasification characteristics during microwave heating were studied. During the gasification of carbon dioxide, the main products were gas, followed by char, and tar in terms of the amount. The main components of the producer gas were carbon monoxide and hydrogen including a small amount of methane and light hydrocarbons. They showed a sufficient heating value as a fuel. The generated tar is gravimetric tar, which is total tar. As light tars, benzene (light aromatic tar) was a major light tar. Naphthalene, anthracene, and pyrene (light polycyclic aromatic hydrocarbon tars) were also generated, but in relatively small amounts. Ammonia and hydrogen cyanide (precursor for NO_x) were generated from thermal decomposition of tar containing protein and nitrogen in sewage sludge. In the case of sludge char, its average pore diameter was small, but specific area, pore volume, and adsorption amounts were relatively large, resulting in superior adsorption characteristics.