• Title/Summary/Keyword: Air pollutants concentration

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Applications of a Coupled Multizone and CFD Simulation to Validate Airflow and Influenza A Contaminant Dispersion in Biosafety Laboratory (생물안전밀폐시설에서 Multizone과 CFD 연동해석에 의한 실내기류 및 Influenza A 오염농도해석)

  • Hwang, Ji Hyun;Hong, Jin Kwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.588-593
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    • 2014
  • To maintain a negative pressure, the supply, exhaust airvolume are adjusted by setting volume damper and the infiltration through leakage area of the door between rooms in biosafety laboratory. Multizone simulation is useful way to predict room pressure, supply and exhaust air volume. But in a particular room, local change such as airflow and contaminants concentration distribution can not be evaluated unfortunately. Through this study, a coupled multizone and CFD simulation was performed, indoor air flow and local contaminants concentration distribution in a particular room of BSL lab are predicted. The results show that all zones of BSL lab are well ventilated by unidirectional flow without local stagnation. In addition, in case that unexpected biohazard is occured in BSL lab, multizone simulation results about the spread of pollutants along movement of the occupant also show that contaminants concentration is removing totally without the spread of the outside. In conclusion, a coupled multizone and CFD simulation can be applied to interpret differential pressure in room and local change of physical quantity in a particular room such as airflow and Influenza A contaminants concentration distribution. This simulation method is useful to enhance the reliability and accuracy of biosafety laboratory design.

Current Status of Radon Management in the 5678 Seoul Metropolitan Rapid Transit Subway (5678 서울도시철도 지하역사의 라돈 관리 현황)

  • Kim, Jun-Hyun;Yoon, Hun-Sik;Seo, Kang-Jin;Woo, Hee-Yeong;Kim, Man-Hwa;Park, Jong-Hun
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.1306-1312
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    • 2011
  • Underground Subway station's air pollutants are introduced from the indoor or outdoor. And Radon is a major pollutant in the subway station. Radioactive substances Radon is occuring naturally in granite tunnel wall and underground water. Especially inert gas Radon that causes lung cancer in human is anywhere but 5678 S.M.R.T. tunnels deep and pass through the granite plaque have a lot of Radon. The Radon concentration is determined by the following reasons : radon content of soil and concrete, underground water, ventilation, pressure difference, building structure, temperature, etc. So Radon concentration is hard to predict. And we can't only ventilate owing to era of high oil prices. This study focuses on our efforts for the reduction of Radon concentration. And the purpose is to provide basically datas of specially managed 15 subway station's Radon concentration.

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Investigate on the rate of change of CO concentration in a tunnel under changed position of the jet fans by using numerical method (제트 팬 가동위치에 따른 장대터널 내 CO 농도 변화율에 대한 전산해석)

  • Min, Jae-Hong;Kim, Dae-Hyun;Chung, Jin-Taek
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2765-2770
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    • 2008
  • The purpose of tunnel ventilation system for long road tunnels is to keep certain levels of Visibility Index and the concentration of CO. Additional equipments such as jet fans are used in road tunnel to discharge pollutants in the road tunnel. The control algorism of tunnel ventilation system takes the value of sensors as input, and then gives the operation method of jet fans in tunnel as output. Information on the variation of CO concentration in tunnel when jet fans are running is needed to minimize their operation time. Numerical analysis is used in this paper because of the difficulty of conducting experiments under standard condition for ventilation of road tunnel. The concentration of CO has been calculated by using 3-dimensional CFD under transient condition with speed of cars, quantity of air ventilation, and the results for various operation position of jet fans are compared.

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Removal of Air Pollutants from Charcoal Production Process Exhaust (숯 제조공정에서 발생하는 대기오염물질의 제거기술)

  • Park, Seong-Kyu;Choi, Sang-Jin;Kim, Daekuen;Hwang, Ui-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.4
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    • pp.350-361
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    • 2014
  • Exhaust gas containing wood tar of high concentration is discharged from charcoal production kilns. The large amount of emissions are often found by operational failure. The purpose of this study is to investigate the performance of an integrated treatment system in treating charcoal production exhaust. The system, which combined a tar collection device and a post-combustion unit, was proposed to remove moisture, wood tar, particulate matter, and other gas-phase pollutants (CO, $CH_4$, total hydrogen carbons) from exhaust gases. Heat recovery units were also applied in the system to utilize waste heat.

A Study on the Prediction of SO2 Concentration in local Circulation of Mesoscale (중규모 국지순환에서 이산화황의 농도예측에 관한 연구)

  • Lee, Hwa-Woon;Kim, Yoo-Keun;Jang, Eun-Suk
    • Journal of Environmental Science International
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    • v.5 no.3
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    • pp.277-284
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    • 1996
  • The Characteristics of atmospheric flow and dispersion of air pollutants in the mountainous coastal area were studied using two-dimensional model by the combination of land-sea breezes and transport. The pollutants emitted into the simulated wind field in considering with the mesoscale local circulations. The typical effects of land-sea breezes and tophography of coastal area on the dispersion are discussed in detail, and the model is proved as an useful tool to pridict real time pollutant transport by the results of application studies in Pusan, Korea where the urbanized coastal area with mountainous topography. It was found that sulfur dioxide ($SO_2$) are differently transported and concentrated as going inland by the influence of the sea breeze with topographic changes. Key words : land-sea breezes, sulfur dioxide, dispersion, coastal area.

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Emission Characteristics of Air Pollutants produced from Idling of Vehicles (차량 공회전시 배출되는 대기오염물질의 배출 특성)

  • 이병규;조성웅;나덕재;정혁용;정광륜;이채복
    • Journal of Environmental Science International
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    • v.8 no.1
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    • pp.27-32
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    • 1999
  • This study identified concentrations of all pollutants emitted from idling of vehicles such as cars, taxis, trucks, and buses. In this investigation we analyzed concentrations of $SO_2$, NOx, CO, and $CO_2$ omitted from exhaust pipe of vehicles as a function of vehicle type, mileage, exhaust volume, and fuel type using the GreenLine. Compact or light cars, which have relatively low exhaust volume, showed much higher exhaust concentrations of $CO_2$, CO, and NOx than those emitted from vehicles with high exhaust volume. Vehicles using light oil showed much higher exhaust NOx concentrations than those of vehicles using gasoline. Vehicles using LPG and compact cars showed very high exhaust CO concentration compared to other vehicles. NOx exhaust concentrations were increased with increasing the mileage of vehicles.

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An Estimation of Emission Reduction Rates to Achieve the Target Air Quality in Seoul Metropolitan Area (수도권 지역별 목표대기질 달성을 위한 오염배출 삭감율 산정 연구)

  • Kim, Jeongsoo;Kim, Jiyoung;Hong, Jihyung;Jung, Dongil;Ban, Soojin;Park, Sangnam
    • Journal of Environmental Impact Assessment
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    • v.16 no.1
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    • pp.1-13
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    • 2007
  • This study was carried out to estimate the emission reduction rates for the regional allowable emissions by special measures to achieve the target air quality in Seoul Metropolitan Area (SMA). A modeling system was designed to validate the details in enforcement regulations set up by local governments based on the current status and plans for air quality improvement. Modeling system was composed of meteorological model (MM5), emission model (SMOKE), and air quality model (CMAQ). Predicted results by this system show quiet well not only daily air pollutants concentration but also the tendencies of wind direction, wind speed and temperature. To achieve the target air quality in Seoul Metropolitan Area (SMA), emission allowances are estimated by seasons and regions. Referring to the base year 2002, it was estimated that emission reduction rates to achieve the intermediate goal in 2007 were 14.2% and 16.6% for NOx and $PM_{10}$, respectively. It was also estimated that 52% of NOx and 48% of $PM_{10}$ reductions from the base year 2002 would be required to accomplish the air quality improvement goal of 22 ppb for $NO_2$, and $40mg/m^3$ for $PM_{10}$ in year 2014. To improve $NO_2$ and $PM_{10}$ concentration through emissions reduction policies, it was found that emissions reduction for the on-road mobile sources would be the most effective in SMA.

Analysis on the Effects of Traffic Control Program on the Air Quality in Seoul (자동차 부제에 의한 서울 대기오염 저감 효과 분석)

  • Lee, Hyung-Min;Kim, Yong-Pyo
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.4
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    • pp.498-506
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    • 2007
  • To reduce the vehicular emissions of air pollutants, various traffic control programs (TCPs) have been used. In 2002, two TCPs have been implemented in Seoul and Busan, respectively. In this study, based on the study results on the effectiveness of the TCP in Seoul (Kim et al., 2005) and Busan (Lee et al., 2006), emission reduction by the TCP in Seoul was estimated and their contribution to the ambient air pollutants' concentrations was discussed. During the TCP period in 2002 at Seoul, emissions of air pollutants were reduced by 35% for CO and $NO_2$, 80% for HC, 23% for $PM_{10}$, and 24% for $SO_2$. Vehicular emission reduction affected the ambient concentrations significantly for $NO_2$. However, for $SO_2$, vehicular emission reduction did not affect the ambient concentration significantly. For $PM_{10}$, vehicular emission reduction did not affect the ambient concentration significantly if considering fugitive emissions.

Estimating Climate Pollutants Emissions and Service Demands considering Socio-economic Change: Residential·Commercial Sector, Transportation Sector, Industrial Sector (사회경제 변화를 고려한 서비스 수요 및 기후변화 유발물질 배출량 예측: 가정·상업부문, 교통부문, 산업부문을 중심으로)

  • Park, Jin-Han;Lee, Dong-Kun;Lee, Mi-Jin;Park, Chan;Jung, Tae-Yong;Kim, Sang-Kyun;Hong, Sung-Chul;Baek, So-Jin;Lee, Jang-Hoon
    • Journal of Climate Change Research
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    • v.6 no.4
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    • pp.291-302
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    • 2015
  • Vulnerability due to climate change depends on the concentration of carbon dioxide emissions over several upcoming decades. The objective of this study is to estimate the concentration of greenhouse gases and air pollutants in 2100, while also accounting for expected socio-economic changes in Korea. First, we intend to prepare scenarios for possible socioeconomic changes in Korea: business as usual (BAU), high growth and low growth. Secondly, we aim to predict services demands in residential?commercial sector, transportation sector, industrial sector for each scenarios. Finally, the emissions of LLGHG and SLCP will be estimated on the basis of the predicted service demands. The study results project that in Korea, LLGHG emissions will be approximately $660Mt\;CO_2\;eq$. and SLCP emissions will be approximately 3.81 Mt, -including black carbon (BC) by 2100. The transportation and industrial sectors are the major source for LLGHG emissions, and the residential and commercial sector serve as the SLCP source. Later, additional studies on the cost and benefit of mitigation should be carried out by comparing the reduced use of materials that cause climate change as a result of reduction policies and the socioeconomic cost.

Removal Efficiencies Estimation of Air Pollutants at Wet Scrubber Using Activated Carbon (활성탄 사용에 따른 습식세정시설에서의 대기오염물질 제거효율 평가)

  • 신찬기;권명희;전종주;신대윤
    • Journal of environmental and Sanitary engineering
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    • v.18 no.2
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    • pp.87-93
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    • 2003
  • This study carried out to recommend adaptable technologies and countermeasures for performance improvement of Wet Scrubber(WS) in industrial waste incinerator. When not using the Activated Carbon(AC), the removal efficiency of dust and HCl is 73%, 92%. And particulate phase and gaseous phase dioxins removal efficiency was evaluated up to 31% and 12%. In this case, dioxins enrichment was not revealed in WS. When using the AC mixing with scrubbing water, the case of 1,000ppm, removal efficiency of particulate phase dioxins was about 51%, and gaseous phase dioxins was about 96%. The case of 2,000ppm, removal efficiency of particulate phase dioxins was about 55%, and gaseous phase dioxins was about 97%. And the case of 3,500ppm, the removal efficiency of particulate phase dioxins was about 35%, and gaseous phase dioxins was about 96% respectively. By this study, using the AC was more useful to remove the gaseous phase dioxins, and needed to use proper concentration of the AC, that in case of 3,500ppm, the particulate phase dioxins removal efficiency was more lower than other cases.