수도권에 위치한 S매립장 내 3개의 매립장을 대상으로 매립가스 배출 및 주요 경로별 표면 발산과 관련된 분석을 하였다. 전체 매립가스 발생비율 10.9%인 LS1이 총 표면발산 비중은 49.4%를 차지하고 있었다. 3개 매립장에서의 메탄의 총 표면발산은 13.6 Nm3/min로서, LS1 8.4 Nm3/min (61.7%), LS2 4.0 Nm3/min(29.4%), LS3 1.2 Nm3/min(8.9%)이고, 발산경로별로는 상부 7.3 Nm3/min (53.2%), 사면 6.4 Nm3/min(46.7%), 다이크 0.02 Nm3/min(0.1%)이었다. 3개 매립장의 주요 배출경로 별 산화율은 다이크가 87.5%로 가장 크고, 상부 72.3%, 사면 71.8% 순이었다. 메탄을 기준으로 표면발 산 기여율은 매립장 별로 LS1이 전체의 61.7%로 가장 컸다. 주요 배출경로별로는 LS1의 사면이 전체의 41.7%, LS2의 상부 24.4%, LS1의 상부 20.0%로서 S매립장의 전체 메탄 표면발산량의 86.1%를 차지함 에 따라 향후 집중적인 관리가 필요할 것으로 판단되었다.
The effect of the change in air inflow velocity has been investigated at the opening of the malodor emission source to determine its influence on the Complex odor concentration. Both the Complex odor collection efficiency and concentrations were measured according to the change in airflow velocity. When the air inflow velocity was 0.1 m/s, it was observed that some of the generated gas streams were diffused to the outside due to low collection efficiency. In contrast, only the increased gas collection volume up to 0.5 m/s showed no substantial reduction of the Complex odor concentration, which indicates an increase in the size of the local exhaust system as well as the operation cost for the Complex odor control device. When the air inflow velocity reached 0.3 m/s, the Complex odor concentrations not only were the lowest, but the odorous gas could also be collected efficiently. The air inflow velocity at the opening of the malodor emission source was considered the key factor in determining the gas collection volume. Therefore, based on the results of this study, an optimal air inflow velocity might be suggestive to be 0.3 m/s.
In this study, the loading rates (or emission rate) and concentrations of air pollutants (ammonia, hydrogen sulfide, carbon dioxide, methane, nitrous oxide, and particulate matter (PM2.5, PM10 and TSP)) emitted from a naturally ventilated dairy facility were analyzed and compared to enable a better understanding that are in close proximity to each other, air pollution status. In general, the pollution patterns should be similar in measurement sites that are in close proximity to each other, and this hypothesis was fundamental to our approach in this study. For the comparison in nearby different sites, monitoring points were located at inside (source site) and outside the dairy building (ambient site), and concentrations and wind velocity were simultaneously monitored in real time. The patterns of PM2.5 emission rate and loading rate were similar in the source site and the ambient site which was consist with the hypothesis, while the PM2.5 mass concentration were not similar in both sites. As well as PM2.5, the emission rates (source site) of gaseous carbon dioxide (CO2) and nitrous oxide (N2O) were highly correlated to their loading rates (ambient site), while the concentrations of CO2 and N2O were not similar. Therefore, wind velocity, which is included in the emission or loading rate, should be simultaneously monitored with the concentration at the same measurement points for better understanding of the air pollution status.
This study aimed to estimate the odor emission rate from swine nursery facilities (naturally and mechanically ventilated) using probability distribution. Odor occurrence trends in the study facilities were very different; odor concentration and gas flow had a lognormal distribution. Monte Carlo simulation was used to carry out the uncertainty analysis. Odor emission rate was found to range from 18.05 OU/sec (10th percentile) to 621.88 OU/ sec (90th percentile), and odor emission rate per head ranged from 0.02 OU/sec · head (10th percentile) to 0.64 OU/ sec · head (90th percentile).
In this study, we investigated the effects of EGR rate and engine load on the emission characteristics in a 4-cylinder common rail direct injection diesel engine fueled with canola oil biodiesel (BD) blended fuel. The biodiesel blend fuel, BD20 (20 vol.% biodiesel and 80 vol.% ULSD blend) was used at an engine speed of 1,500rpm. The experimental results showed that with the increasing of EGR rate, the combustion pressure and rate of heat release (ROHR) of three test fuels were decreased, and the ignition delay was extended, the carbon monoxide (CO) and particulate matter (PM) emissions increased slightly, but the nitrogen oxide (NOx) emission decreased clearly. On the other hand, with the increasing of engine load, the combustion pressure and ROHR were increased, and the CO and PM emissions decreased. However, the NOx emission was increased due to the rise of the combustion temperature.
In this study, leachate treatment facility (outlet, facility inside) and landfill sections (vent systems, landfill surface)of nine landfills is being buried in korea were studied emission characteristics of odor compounds. Air dilutionvalue in ventpipes of landfill section was generally highest and was more 3 times higher than emission standard(air dilution value of facilities outlet : 500) in Daejeon, Tongyeong, and Busan landfill. Outlet of leachate treatmentfacilities in Tongyeong and Daegu landfill, in case, was higher respectively 20 times, 6 times than other landfills,commonly show that a large contribution to the odor of hydrogen sulfide. In case of ordor emission rate, ammoniaand hydrogen sulfide were surveyed to comprise a high rate for odor emission rate. Odor emissions based onlandfill scale, large landfill (Sudokwon) and small landfills (Yeosu, Chuncheon, Chungju) is low in odor emissionsper unit area, whereas medium landfill (Busan, Daejeon, Daegu) was estimated to be high odor emissions. In caseof large landfill, leachate treatment facilities is management in good condition and discharged odor emission oflandfill sections was low into ambient air. In case of small landfill, decay gases and leachate is few. Thereforeodor emissions is fewer than estimated medium landfill. In case of medium landfill, management condition ofleachate treatment facility was in poor and landfill sections was under not stabilization stage. Thus, mediumlandfills was identified that needs to be intensive care.
난의 종류별로 심비디움, 심비디움 교배종, 덴팔레, 온시디움, 호접란, 그리고 나도풍란의 음이온 발생량을 조사하였으며, 심비디움 20, 40, 60, 80%와 심비디움 교배종 25, 50, 75, 100%의 투입율에 따른 음이온 발생량의 변화를 조사하였다. 그 결과 심비디움 332개 /cm3, 심비디움 교배종 323개/cm3로 심비디움 속이 가 장 발생량이 많았으며, 그 다음이 덴팔레 250개/cm3, 온시디움 203개/cm3, 나도풍란 119개/cm3, 호접란이 77개/cm3 순이었다. 투입율 증가에 따라 심비디움은 40%, 심비디움 교배종은 75%까지는 음이온 발생량이 증가하였으나, 그 이상 투입율에서는 다소 감소하는 경 향이었다. 따라서 식물 종류별로 음이온 발생량을 상호 비교하기 위해서는 식물 투입율이 40% 이하가 적절하 며, 상대습도 등을 감안할 경우 약 30% 정도가 가장 적절한 것으로 보인다.
This study was performed to estimate the emission rate of volatile organic compounds (VOCs) and to evaluate the risk level affected by indoor air pollutants (IAPs) in 27 new apartments (prior to residence) in Seoul City from December 2004 to March 2005. The indoor air pollutants investigated in this study include formaldehyde, several aromatic VOCs (benzene, toluene, styrene, xylene, and ethylbenzene). All measurements were made based on the standard method of Ministry of Environment in Korea. The indoor concentration levels for benzene, xylene, toluene, ethylbenzene, styrene, and formaldehyde have significant increase trend 5 hours after closing windows and doors. Levels of air pollutants did not exhibit significant difference between living rooms and bedrooms. The air exchange rates by the concentration decay method using SF6 were 0.37 for low floor, 0.32 for middle floor, and 0.75 for high floor. The emission rate showed the highest level in the middle floor and second one in the low floor, when estimated by the IAQ model for benzene, toluene, ethylbenzene, xylene, styrene, and formaldehyde. Considering the above result, it is suggested that the estimation of emission rate be considered when the new apartment is designed and constructed with respect to construction materials to emit low VOCs. Moreover, the related regulation should be established for IAQ management.
The purpose of this experimental study is to develop the waterborne silicon acrylic surface finishing material of parking lots. Pollutant emission test was conducted in order to give a guide datum for developing the material by implementing modified polyamide resin. As a result, specimens satisfied with the quality standard regarding TVOc, HCHO, Toluene which is prescribed in KS F4937. As conclusion, this study confirmed that the developed finishing material could be an optimized surface finishing material usable for parking lot floor.
In order to clarify the contribution rate of PM concentration due to regional emission distribution, Brute force analysis were carried out using numerical estimated PM data from WRF-CMAQ. The emission from Kyeongki region including Seoul metropolitan is the largest contribution of PM concentration than that from other regions except for emission of trans-country and source itself. Contribution rate of self emission is also the largest at Kyeongki region and its rate reach on over 95 %. And the rate at Gangwon region also higher than any region due to synoptic wind pattern. Due to synoptic wind direction at high PM episode, pollutants at downwind area along from west to east and from north to south tends to mix intensively and its composition is also complicated. Although the uncertainty of initial concentration of PM, the contribution of regional PM concentration tend to depend on the meteorological condition including intensity of synoptic and mesoscale wind and PM emission pattern over upwind region.
This paper attempted to estimate the emissions of HFC-134a from scrap truck as a result of measuring the residual quantities of HFC-134a in air conditioner of scrap truck. We measured the residual amounts in the scrap truck of 138 by applying commercial recover for refrigerants. The average residual rate(disposal-phase emission factor) is reported to be 44.3±3.3% within a confidence interval of 95%. Recent year model trucks exhibit the higher residual rates. Little variation, however, is observed in regard to vehicle size. The HFC-134a emission quantity from scrap truck in 2011 is estimated to be 55,908 tCO2-eq that demonstrates 21.4% increase to compare with that in 2007. As the numbers of truck have increased dramatically during the last two decades, the emissions of HFC-134a from scrap truck would increase sharply in the next coming years. HFC-134a is a very high GWP greenhouse gas. therefore have to reduce the emissions from the scrap truck and need to find ways to recycle. The chemical compositions of refrigerants from scrap truck are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap truck could be reused as refrigerant.
This paper attempted to estimate the emissions of HFC-134a from scrap passenger vehicles as a result of measuring the residual quantities of HFC-134a in scrap vehicles. We measured the residual amounts in the scrap passenger vehicles of 196 by applying commercial recover for refrigerants. The average residual rate is reported to be 61.2 ± 2.4% with a confidence interval of 95%. As expected, the higher residual rates are shown for recent models. Little variation, however, is made with vehicle size. The HFC-134a emission quantity from scrap passenger vehicles in 2011 is estimated to be 326,236.83 tCO2 eq that demonstrates 53% increase to compare with that in 2007. As the numbers of passenger vehicles have increased dramatically during the last two decades, the emissions of HFC-134a from scrap passenger vehicles would increase sharply in the next coming years. The chemical compositions of refrigerants from scrap passenger vehicles are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap passenger vehicles could be reused.
Emission rates of biogenic hydrocarbon emitted from broad-leaved trees grown at Jeju Island were estimated using a dynamic enclosure method. Leaf temperature, PAR and relative humidity were monitored during the sampling time. The emission rates of isoprene and monoterpene were measured for five plants(Carpinus laxiflora, Quercus serrata, Styrax japonicus, Quercus acutissima, Quercus crispula) during the sampling period at the Halla mountain sites. Among five tree species, the highest isoprene emission rate of 10.60 ㎍ gdw-1hr-1 was observed for Quercus serrata. The seasonal emission rates were the highest during summer and the emission of isoprene was highly affected by light and temperature variations. The highest emission rate of isoprene was occurred between 13:00 and 14:00, but isoprene was not emitted in nighttime because of the absence of light.
Indoor air quality is the dominant contributor to total personal exposure because most people spend a majority of their time indoors. Especially when indoor environments have sources of contaminants, exposure to indoor air can potentially pose a greater threat than exposure to ambient air. In this study, estimations of volatile organic compounds and formaldehyde emission rate in indoor environments of new apartments were carried out using mass balance model in indoor environment, because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. Considering the estimated emission rate of volatile organic compounds and formaldehyde, it is suggested that new apartment should be designed and constructed in the aspect of using construction materials to emit low hazardous air pollutants.
Odor sources of a chemical plant in Ulsan were surveyed and temperatures, humidities and flow rates of each exhaust gas were measured. The air samples collected from each source were transferred to the laboratory for sensory test and their odor concentrations were investigated. The odor emission rate of each source was estimated from the recorded results and assigned the sources expected to be needed for the odor prevention policy using the simple prediction equation of the affection by malodor to the nearest residential area. From the total odor emission rate of the examined plant and the relation table for expectable affection area, it was concluded that total odor emission of this plant might be decreased for the prevention of residential complaint.
A case of air pollution study of estimation of emission rate for source to railroad rolling stock and emissive character about is unusual. Recent emission rate of railroad rolling stock was estimated with emission factor of EPA in three region(Seoul, Incheon, and Gyeonggido). But this EPA factor could be incorrect because Korea and America have a different railroad environment in the variety of fuel and character of railroad rolling stock. In this study, emission rate of each line, car and region(district) with emission factor of Korean case(National Railroad Administration, 1997) was estimated. In Busan Metropolitan City, railroad rolling stocks were divided accoding to, each line, car and service. Particularly, the idle fuel rate omitted in the preceding study was included in calculation fuel rate. Total emission rate of Busan Metropolitan City was 887.41t/year. Each emission rates of Kyeongbu line, Donghaenambu line, Gaya line, Uam line, Bujeon line, and idle was 489.15t, 196.46t, 33.94t, 12.66t, 6.47t, and 148.72t, respectively.