• Analytical Science and Technology
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• v.18 no.5
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• pp.419-424
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• 2005

In recent years, dioxins which were designated as persistent organic pollutants and endocrine disrupters are treated as substance of environmental pollution and studied about human health risk assessment, emission pollutants estimation, analytical methods and so on. It is easy that dioxins are accumulated to soil because of the atmosphere circulation of burning up the waste. This is the comparative studies on the distribution relationship of dioxin isomers in exhausted gas of industrial waste and urban waste incinerators, ambient air and soil. A basis of PCDDs and PCDFs based on OCDD was drawn up to the curve and they correspond to dioxin isomers in exhausted gas of industrial waste and urban waste incinerators and ambient air. On comparing these results, It was found that the ambient air and exhausted gas of industrial waste incinerators were very similar in curve and ratio. Consequently, environmental by exposed dioxin depends on the exhausted gas of industrial waste incinerators than urban waste incinerators. In case of soil, even though we can not completely rule out the possibility of pollution source bring on pesticide and other factors, and naturally biological dissociations, the curve shape is very similar to exhausted gas of industrial waste incinerators and ambient air. So, we inform here that it was mainly caused by these environmental factors.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.349-359
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• 2005

In this study, we focused on the geographical and the meterological conditions, the atmospheric examination, the soil contents and compositions in order to establish cultural properties conservation plan in Gyeongju and its surroundings. Also, the transport route with environmental contaminants in Ulsan and Pohang was examined. The results could be summarized as follows ; Air pollutant and environmental contaminant was transported by two types of winds. One is induced by local winds, the other is induced by synoptic winds. Air contaminant transported from coastal regions to inland regions were associated with wind velocity. Gyeongju had good atmospheric conditions, i.e. $SO_2\;0.009{\sim}0.011ppm,\;CO\;0.6{\sim}0.8ppm,\;NO_2\;0.015{\sim}0.020ppm,\;O_3\;0.017{\sim}0.032ppm,\;PM_{10}\;46{\sim}62{\mu}g/m^3\;and\;Pb\;0.034{\sim}0.060{\mu}g/m^3$, which was below environmental air qualify standards and was little lower than those of Pohang and Ulsan. However, Ulsan and Pohang city are located on south-east coast and have many industrial facilities. Hence, air pollution problems become serious issues in Ulsan, Pohang, Busan, Daegu and other cities due to the emission of air pollutants from the various industrial facilities, incinerator and power plants, etc. The soil of Gyeongju had heavy metals conditions, i.e. $Cd\;0.01{\sim}0.08mg/kg,\;Cu\;N.D{\sim}2.39mg/kg,\;As\;N.D{\sim}0.07mg/kg,\;Hg\;N.D{\sim}0.15mg/kg,\;Pb\;0.49{\sim}1.39mg/kg,\;Cr^{+6}\;0.02{\sim}0.42mg/kg,\;Fe\;0.74{\sim}1.55mg/kg,\;Mn\;0.11{\sim}0.49mg/kg\;and\;Zn\;1.11{\sim}3.56mg/kg$. However, pH value of soil had range of $4.12{\sim}7.45$. The results showed that high pH concentration of soil could occur due to air pollution diffusion and environmental contaminant transport at Ulsan and Pohang city.

• Journal of Environmental Science International
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• v.13 no.7
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• pp.645-653
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• 2004

Indoor air quality is affected by source strength of pollutants, ventilation rate, decay rate, outdoor level, and so on. Although technologies measuring these factors exist directly, direct measurements of all factors are not always practical in most field studies. The purpose of this study was to develop an alternative method to estimate these factors by application of multiple measurements. For the total duration of 30 days, daily indoor and outdoor $NO_2$ concentrations were measured in 30 houses in Brisbane, Australia, and for 21 days in 40 houses in Seoul, Korea, respectively. Using a box model by mass balance and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor (emission rate divided by sum of air exchange rate and deposition constant) were calculated, Sub-sequently, the ventilation and source strength were estimated. In Brisbane, the penetration factors were $0.59\pm0.14$ and they were unaffected by the presence of a gas range. During sampling period, geometric mean of natural ventilation was estimated to be $l.l0\pm1.5l$ ACH, assuming a residential $NO_2$ decay rate of 0.8 hr^{-1}$ in Brisbane. In Seoul, natural ventilation was $1.15\pm1.73$ ACH with residential $NO_2$ decay rate of 0.94 hr^{-1}$ Source strength of $NO_2$ in the houses with gas range $(12.7\pm9.8$ ppb/hr) were significantly higher than those in houses with an electric range $(2.8\pm2,6$ ppb/hr) in Brisbane. In Seoul, source strength in the houses with gas range were $l6.8\pm8.2$ ppb/hr. Conclusively, indoor air quality using box model by mass balance was effectively characterized.

• Advances in Energy Research
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• v.6 no.1
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• pp.1-15
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• 2019

The objective of the study is to examine the relationship between water resources, energy demand, food production, and environmental pollutants in selected SAARC nations, namely, Bangladesh, India, Pakistan, and Sri Lanka, during the period of 1990-2016. The results show that water, energy, and food (WEF) resources substantially affected air quality in the form of high mass carbon emissions, fossil fuel energy demand, methane discharges, nitrous oxide emissions, and greenhouse gas emissions in these countries. Food production and food deficit largely increase $CO_2$ emissions due to unsustainable production and malnutrition, while land use under cereal production increases $CH_4$ and $N_2O$ emissions. Electricity production escalates $CO_2$ emissions and fossil emissions across countries. The results support the carbon EKC hypothesis, while monotonic increasing function exists in case of fossil fuel energy. The study emphasizes the need to ensure environmental sustainability agenda by adopting cleaner production technologies in WEF resources.

• Journal of Urban Science
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• v.11 no.2
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• pp.45-54
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• 2022

Recently, regulations on automobile exhaust gas emission are being strengthened. Accordingly, automobile exhaust gas emissions are expected to decrease and continue to decrease. On the other hand, many countries do not yet consider the emission of non-exhaust air pollutants from automobiles as important. Automobile non-exhaust substances are classified into three categories: tire dust emissions, brake wear emissions, and road scattering dust. In particular, in the case of tire dust, research results exist that pollutant emissions increase as the weight of a vehicle increases. Since the weight of trucks varies according to the load and the load along the axles is also different, it can be expected that the emission of PM10 from the tire dust will be different depending on the loading method. Therefore, this study was conducted on the amount of PM10 generated in tire dust considering the axle load of the truck according to the loading method. However, it was confirmed that the total amount of PM10 was less than that all loads are loaded in the front or rear when the load was evenly distributed in the front and rear of the cargo compartment. In particular, if the load is distributed evenly in the front and back of the cargo compartment and the load in the front part is divided into 2 to 6 and loaded, as the number of divided loading increases the amount of PM10 generated decreases. And when the load is divided into 6 pieces, the total amount of PM10 generated is 0.3952g, the minimum value. If the load is divided into 6 or more and loaded evenly, the total PM10 generated continuously increases and converges to about 0.3964g.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.10
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• pp.729-753
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• 2008

Oxy-fuel combustion is a reliable way for the reduction of pollutants, the higher combustion efficiency and the separation of carbon dioxide. The review of recent research trends and the prospects of oxy-fuel combustion were presented. The difference in characteristics among oxy-fuel combustion, conventional air combustion, oxy-fuel combustion with flue gas recirculation (FGR) technique was investigated. Recent experiments of oxy-fuel combustion with/without FGR were surveyed in various ways which are optimized burner design, flame characteristics, the soot emission, the radiation effect, the NOx reduction and the corrosion of combustor. Numerical simulation is more important in oxy-fuel combustion because flame temperature is so high that conventional measurement devices have a restricted application. Equilibrium and non-equilibrium chemical reaction mechanisms for oxy-fuel combustion were investigated. Combustion models suitable for the numerical simulation of non-premixed oxy-fuel flame were surveyed.

• Journal of ILASS-Korea
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• v.25 no.1
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• pp.27-33
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• 2020

NOx, PN and CO emissions from diesel trucks make up a significant portion of domestic air pollutant emissions. Therefore, test vehicles with various emission standards and driving modes were selected to evaluate the emission characteristics of regulated pollutants (NOx, PN, CO) in medium-duty trucks. As a result of test, all test vehicles were satisfied with Euro 5 or 6 regulation. NOx emissions of Euro 6 vehicles with after-treatment of LNT + DPF were lower than those of Euro 5 vehicles with DPF. In WLTC mode, all vehicles have high NOx emissions at section of extra high speeds, which are determined by increased fuel consumption and high combustion temperatures. CO and PN emissions from all vehicles were found to be low at section of low speeds. Also, The NO₂/NOx ratio was analyzed at 7-23% in each mode, and the NO₂/NOx ratio increased as the average vehicle speed increased. In NIER 9 mode, the CO, HC, and PN emissions were higher under cold conditions of engine than hot conditions of engine. In addition, vehicles with after-treatment system of LNT have similar NOx emissions level in this study.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.370.1-370.1
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• 2016

Volatile organic compounds (VOCs) are considered hazardous air pollutants and these are emitted from building materials and household products. VOCs can cause global warming as well as human sickness, and even cancer. Photocatalysis provides a way of converting VOCs into harmless materials. Various researches have shown that $TiO_2$ is the most efficient photocatalysts due to its excellent activity. In this study, metal/non-metal doped $TiO_2$ particles are synthesized for the enhancement of the photocatalytic properties of pure $TiO_2$. By metal/non-metal doping, band gap energies of prepared samples were analyzed by UV/Visible spectrophotometer. The physical and chemical properties of synthesized powder were characterized by field emission scanning electron microscope, by BET for measuring their specific surface area, and by XRD for phase identification and particle size determination. Degradation ability for p-xylene was evaluated through monitoring the concentration in a closed chamber. Relation between their properties and decomposition abilities for VOC were evaluated based on the experimental results.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.572-576
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• 2002

Volatile Organic Compounds(VOCs) contribute to the formation of ozone and PAN which are injurious to health through complex photochemical reactions. Growing consumption of fossil fuels results in significant emission of VOCs and other air pollutants into the atmosphere. In this study, Ambient an grab samples of VOCs were collected at the platform and the concourse of six stations in the subway from February 21th to 28th. Among the total contents, Toluene (118.74 ppm) showed the highest concentration in the Indukwon station platform while other contents were measured low concentrations. Also, the platform concentrations were higher than the concourse concentrations through the whole contents.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.813-816
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• 2009

A commercial-scale RDF boiler that its burning capacity is 400 kg-RDF/hr and steam production capacity is 2 ton/hr. It has a chain type stoker and waste heat recovery system. Heat exchanger is vertical water-pipe so that soot blowing and removal is convenient during operation. Dry scrubber, bag filter and activated carbon tower have been installed for the reduction of air pollutant gases and dust. Analysing data of pollutants from stack such as $SO_x$. $NO_x$ and dioxin shows so good results that the boiler system could comply the regulated emission limits.