Calpuff 역모델링 기법을 이용해 산출된 자료는 오염물질 발생량을 예측할 수 있으며, 여러 가지 자료 비교를 통해 감축 가능성 및 목표 수립이 가능해졌다. 본 연구에서는 동해항 주변지역을 대 상으로 Calpuff 역모델링 기법을 이용하여 대기 중 미세먼지 저감량 설정하기 위한 기초자료 구축에 목 적을 두었으며, 모델링을 이용한 동해항을 포함한 5개 지역 배출농도 산출결과는 다음과 같다. 대기환경기준인 50 ㎍/㎥을 적용하여 대상 지역별 허용배출량 산출 결과 site-D에서 가장 많은 4.95 ㎍/㎡·S의 배출량 저감이 요구되었으며, 4.95 ㎍/㎡·S의 배출량을 감소시킬 경우 영향예측지점(동해하수 종말처리장)의 PM10 평균 예측농도는 42.6 ㎍/㎥로 감소될 것으로 나타났다. site-A(동해항)에서 배출되는 오염물질만을 적용하여 모델링 진행 결과 동해항 주변 민가의 기여농도 는 평균 40~50 ㎍/㎥으로 나타났으며, 배경농도를 고려하면 대기환경기준인 50 ㎍/㎥을 상회 할 것으 로 예상됨에 따라 더 이상의 오염물질 배출량은 허용되지 않을 것으로 판단된다. site-B는 상가와 나대지로 차량 통행과 나대지에서 비산되는 먼지로 인해 0.11 ㎍/㎡·S의 배출량 저감 이 요구되었으며, site-C와 E는 오염물질 저감량은 발생하지 않았으나 지속적인 관리가 요구된다.

The volume of fluid (VOF) method is applied to study the effects of the gas channel cross-section shape on the removal characteristics of a water slug in a trapezoidal PEMFC gas channel. Two different open angles 50 and 60 degrees are selected to investigate the effect of cross-section shape on the behavior of a liquid water slug. In comparison to the 50 degrees case, the water slug is removed slightly faster for the 60 degrees case.

To study the effects of the gas channel wall contact angle on the behavior of a liquid water slug, numerical simulations are performed with the volume of fluid (VOF) method. Two different contact angle combinations on the side and top channel walls are selected. In comparison to the reference case, the water slug is removed faster when the hydrophobic contact angle is applied selectively in the corner section.

PURPOSES: Recently, many local governments have applied chicanes for traffic calming to ensure environment-friendly comfortable and safe roads. However, the geometry of a chicane is designed for speed reduction using a curved portion. This study aims to improve the road geometry conditions of chicanes for reducing carbon emissions and maintaining appropriate driving speeds by considering the relationship between road geometry and carbon emissions. METHODS: This study was conducted as follows. First, carbon emissions corresponding to changing acceleration of vehicles were studied. Second, vehicle acceleration caused by the relationship between the curve radius and the straight length was studied. Accordingly, desirable conditions of curve radius and length of the straight section for reducing carbon emissions were proposed. RESULTS: The existing literature on chicanes present the minimum value of stagger length and path angle in the primary variable condition. This study suggests the maximum values of the curve radius and length of straight section in the primary variable condition. Therefore, if a vehicle’s speed at a chicane is 30 km/h, this study suggests a curve radius of up to 24 m. In addition, if the vehicle’s speed is 24 km/h, this study suggests a length of straight section of up to 6.6 m. These are the geometric conditions for considering the control of acceleration to the vehicle’s maximum speed. CONCLUSIONS: This paper proposes an application of geometric conditions to reduce carbon emissions and maintain appropriate speeds of vehicles through a combination of curve radius and length of straight section.

The objective of this study is to investigate the effect of operating conditions on the performance of small HSDI compression ignition engine. Combustion and exhaust emission characteristics of engine were studied by using CFD simulation with ECFM-3Z combustion model. The conditions of simulation were varied with injection timing, injection pressure, and operating speed, and the results were compared in terms of combustion pressure, rate of heat release, NOx and soot. It was found that as injection timing was advanced and injection pressure is increased, combustion pressure and rate of heat release were increased. As a result, NOx generation is increased. Soot generation is also increased due to the wall film caused by the increase of the injection pressure and locally the rich mixture caused by the effect of the advancing of injection timing.

This paper presents the performance of a CFD model for the near field dispersion of odor from rooftop emissions. The FLUENT Shear-Stress Transport (SST hereinafter) k-ω turbulence model was used to simulate odor dispersion from a rooftop odor vent. The results were compared with a wind tunnel experiment and the calculated results of ASHRAE 2003 and 2007. The FLUENT SST k-ω turbulence model provided good results for making reasonable predictions about the building rooftop surface normalized dilution. It was found that increasing the vent height (from 1 m to 7 m) reduces rooftop surface normalized dilution. ASHRAE 2003 and ASHRAE 2007 performance measures are generally not as good as FLUENT SST k-ω turbulence model performance measures, with larger MG (the geometric mean bias, VG (the geometric variance), NMSE (the normalized mean square error), FB (Fractional bias), and smaller FAC2 (the fraction of predictions within a factor of two of observations).

PURPOSES: The present study aims to evaluate the added CO2 emissions incurred from accelerating operation when to increase the speed up to the allowed level. METHODS : The methodology used are basically the relationship between emission rates and vehicle speeds or acceleration rate. These rates together are used to calculate the added CO2 emissions incurred from accelerating operation. RESULTS: It was resulted that the all the emission rates are increasing proportionally to vehicle speeds or acceleration rates. Additionally, it was also resulted that allowable speeds increasing, the added emission rates are increasing rapidly. CONCLUSIONS: It may be concluded that if the allowable speed ranges are managed, CO2 emissions during vehicle operation are much reduced. From this reason, it was found that the allowable speed during highway design and operation would be much necessary

반도체 공정에서 에칭공정은 실리콘 기판위에 패턴된 절연층을 식각하는 공정으로 분진과 미반응 가스를 배출하며, 다량의 질소와 혼합되어 실질적으로 수 ppm으로 배출되어, 주로 Scrubber를 통하여 후처리가 수행되고 있으나, 처리효율이 저하되는 단점이 있다. 따라서 본 연구에서는 막분리 공정을 통하여 질소와 PFCs를 분리회수하는 통합시스템을 개발하여, PFCs 가스 분리,회수에 대한 평가를 수행하였으며, 회수율 95%, 농축비 1을 나타내었다.

PURPOSES : The authors set out to estimate the related carbon emissions, energy use, and costs of the national freeways and highways in Korea. To achieve this goal, a macro-level methodology for estimating those amounts by road type, road structure type, and road life cycle was developed. METHODS : The carbon emissions, energy use, and costs associated with roads vary according to the road type, road structure type, and road life cycle. Therefore, in this study, the road type, road structure type, and road life cycle were classified into two or three categories based on criteria determined by the authors. The unit amounts of carbon emissions and energy use per unit road length by classification were estimated using data gathered from actual road samples. The unit amounts of cost per unit road length by classification were acquired from the standard cost values provided in the 2013 road business manual. The total carbon emissions, energy use, and cost of the national freeways and highways were calculated by multiplying the road length by the corresponding unit amounts. RESULTS: The total carbon emissions, energy use, and costs associated with the national freeways and highways in Korea were estimated by applying the estimated unit amounts and the developed method. CONCLUSIONS: The developed method can be employed in the road planning and design stage when decision makers need to consider the impact of road construction from an environmental and economic point of view.

Volatile organic compounds(VOCs) are harmful substances that contribute to stratospheric ozone depletion, tropospheric photochemical ozone formation, and carcinogenic human health effects. Worldwide, there are major concerns over the emission of VOCs. Any plans for pollution reduction and management should be established based on database of VOC emission and characteristics. In this paper, the status of VOCs by year, region, and industry were investigated, and then technologies for VOC emission control were introduced. The estimation of VOC emissions by year was gradually increased, and VOC emission due to the utilization of organic solvents was the most common form. VOCs in the atmosphere were detected at the highest concentration in industrial complexes. In most of the industry, it was confirmed that emissions of toluene were the highest among the VOCs. Finally, available VOCs control technologies were introduced, including thermal and catalytic oxidation, adsorption, absorption, biological treatment, non-thermal plasma, electron beam irradiation, and photocatalyst.

The negative factors of fishery in environmental aspect of view are Greenhouse gas emission problems by high usage of fossil fuel, destruction of underwater ecosystem by bottom trawls, reduction of resources by fishing and damage of ecosystem diversity. Especially, the Greenhouse gas emission from fisheries is an important issue due to Cancún meeting, Mexico in 1992 and Kyoto protocol in 2005. However, the investigation on the GHG emissions from Korean fisheries did not much carry out. Therefore, the quantitative analysis of GHG emissions from Korean fishery industry is needed as a first step to find a relevant way to reduce GHG emissions from fisheries. The purpose of this research is to investigate which degree of GHG emitted from fishery. Here, we calculated the GHG emission from Korean bottom pair trawl fishery using the LCA (Life Cycle Assessment) method. The system boundary and input parameters for each process level are defined for LCA analysis. The fuel use coefficient of the fishery is also calculated. The GHG emissions from the representative fishes caught by bottom pair trawl will be dealt with. Furthermore, the GHG emissions for the edible weight of fishes are calculated with consideration to the different consuming areas and slaughtering process also. The results will be helpful to understand the circumstances of GHG emissions from Korean fisheries.

최근 지구 온난화는 세계 경제발전으로 화석연료 사용이 주범으로 인식하고 있다. 이러한 화석연료를 감소하기 위한 연구는 여러 대체에너지 산업으로 발전하고 있으며, 그 중 우리나라에서 생산할 수 있는 연료는 바이오연료이다. 바이오연료는 화석연료에 의해서 발생하는 환경오염 문제를 줄이면서 경제적인 이익을 주는 지속 가능한 연료이다. 그래서 바이오연료를 친환경에너지로 전환시키는 재생에너지 등에 많은 연구가 진행되고 있다. 따라서 본 실험은 어선에서 사용했던 기관을 다시 리모델링하여 실험장치를 직접 제작 설치하였고, 여러 바이오연료를 사용하여 선박의 경제적이고 친환경적인 운항에 도움을 주고자 연구하였다. 유채유, 대두유, 폐유채유의 배기배출물특성에 미치는 영향을 종합적으로 분석한 결과는 연료의 물리적, 화학적 성분이 비슷하여 선박용 엔진에 사용이 가능하고, 연료소비율과 NOx는 약간 증가하였으나, 매연은 많이 감소하는 경향이 확인되었다.

Under Korea’s Enforcement Decree of the Framework Act on Environmental Policy amended in 2013, total organic carbon (TOC) is newly added as water quality parameter to assess organic pollution in the aquatic ecosystem. To meet the TOC requirement and improve quality of effluent discharged into public watershed, it is also necessary to develop standards for TOC in effluent from public sewage treatment works (PSTWs).In this study, we reviewed the characteristics and removal efficiency of TOC in influent and effluent of PSTWs. The study found that phosphorus treatment process removed not only soluble phosphorus but also a portion of TOC remaining after the secondary treatment process. TOC concentration in effluent from PSTWs operated in tandem with industrial wastewater treatment work was higher due to influx of insoluble substances from the industrial wastewater treatment work.In order to lay a foundation for the management of TOC from PSTWs, it is necessary to carry out research on TOC from different perspectives. For example, studies on the generation mechanism of TOC and the impact of TOC on drinking water resources, assessment of effluent qualities through monitoring, and development of measures to control TOC for the preservation of aquatic ecosystem are needed.

This study investigated the emission characteristics of airborne particles and bacteria from six types of household vacuum cleaners in the closed chamber. A test cleaner without HEPA filter was examined focusing on the first one minute of initial operation, observing significant generation of airborne particles, and especially for particle size of 0.5 to 2.5 μm, the generation rate increased up to 68.5 × 103 particles/min. Concentrations of airborne particles and bacteria depends on the production year, the motor power, and the dust filter efficiency of the vacuum cleaner. The observed results should be taken into consideration in the design of the vacuum cleaner as well as how they are operated in indoor environment.

미국과 유럽 등지에서는 자동차용 경유의 방향족 함량이 대기 환경오염의 원인물질로 추정하고 있다. 경유의 총 방향족 및 다고리 방향족 함량 감소가 환경 유해배출가스 HC, NOx, PM 등을 감소시키기 때문이다. 국내에서도 급변하고 있는 차량기술 및 연료품질간의 상관성 규명이 필요한 실정이다. 따라서 본 연구에서는 국내 실정에 맞는 차량과 연료간의 상호작용에 의하여 발생될 수 있는 환경적 영향평가를 진행하였으며 대상으로는 2.2L급 국내 대표 차량 2종(DPF 유 무)과 국내 정제기술로 생산된 5종의 연료를 통하여 경유의 방향족 함량에 따른 배출가스 특성을 분석하였다.