• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.1041-1050
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• 2009

The ambient temperature and concentration of carbon dioxide in Gwangju and the reducing method of temperature, air pollutants were investigated using the atmospheric data in Gwangju. Average ambient temperature ($T_{a-ave}$ was $13.5^{\circ}C$ during 1961 to 2008. The temperature was predicted as increasing of about $2.7^{\circ}C$ in 2108 after 100 years using the trend line of regression equation. Carbon dioxide was 370.7 and 391.4 ppm at Anmyundo, in 1999 and 2008, respectively, showing proportionally increased as ambient temperature. The temperature at Gwangju, $14.2^{\circ}C$ during 1997 to 2008, was a little higher than at neighboring counties as Naju, Damyang, Hwasoon, and Jangsung. In Gwangju, Spring will start in mid-January of 2108, Summer in mid-May, Autumn in mid-October, and Winter in last-December. The average relative humidity in the air ($RH_{a-ave}$) was gradually decreased as the temperature inversely increased. The average $CO_2$ was 457 ppm, which is 65.6 ppm higher than that in Anmyundo, korean background area of $CO_2$ in 2008. Carbon dioxide showed positive correlation, both of them, with carbon monoxide (0.87) and relative humidity (0.48).

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.32-37
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• 2005

The soil properties of the royal tombs (managed by cultural properties administration) located in Seoul and suburban Gyonggi area were investigated to see the influence of the change in soil environment on the royal tomb s이I. To compare the soil chemical properties of four royal tombs soil of Changdeokgung, Jongmyo, Seooneung, and Dongguneung, pH, organic content, available phosphate, extractable calcium, extractable potassium, extractable magnesium, cation exchange capacity, degree of base saturation, and total nitrogen content were measured. The concentrations of Cd, Pb, and Cu measured as the degree of heavy metal contamination can be an indication of atmospheric pollution in the soil environment. To estimate the degree of soil compaction, soil hardness, pore space, porosity, bulk density, and soil atmosphere were analyzed. Through these studies, following conclusions were made: 1. The soil hardness and pore space which can be used as indexes of soil compaction, were worse in the soil of Seooneung than in those of Changdeokgung and Dongguneury. These phenomena seem to be the result of increase in visitors in Seooneung and Dongguneung better and soil management in Changdeokgung and Dongguneung. When three different regions of forest area, prohibited area, and soil compaction area in Seooneung soil were compared, the degree of compaction in the forest area was less than compaction area, indicating the need for the employment of soil resting period in the compaction area. 2. The pH measurements of all four royal tombs soil were higher in top soil than sub soil. The higher soil pH values in Jongmyo and Seooneung seem to result from the application of soil conditioner. In the case of Seooneung, the values for soil pH and organic content were higher in the forest area than those in compaction area. It is thought that active soil management was employed in the forest area through application of organic matters and soil conditioners. 3. The heavy metal contents from soil of Changdeokgung and Jongmyo were higher than that from soil of Dongguneung. Since Changdeokgung and Jongmyo are located inside Seoul, it is thought that the high level of heavy metal concentrations in these royal tomb soil is the result of accumulation of pollutants from the city.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.2
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• pp.141-147
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• 2005

This study investigated air pollutant levels and physiological variation of Ginkgo biloba in Chuncheon. The results were as follows: The annual average concentrations of $SO_2,\;NO_2\;and\;PM10$ were 0.004ppm, 0.013 ppm and $66{\mu}g/m^3$, respectively. The volume weighted average concentrations of ionic components were $SO_4\;^{2-}\;3.584 mg/m^3,\;NO_3^-\; 2.803 mg/m^3,\;Cl^-\;1.485 mg/m^3\;and\;NH_4\;^+\;0.998 mgg/m^3$ in precipitation. The annual wet deposition amount of the major ions was shown to be $SO_4^{2-}\;3.865g/m^2/yr,\;NO_3^-\;2.924g/m^2/yr,\;Cl^-\;2.773g/m^2/yr\;and\; NH_4\;^+\;1.485 g/m^2/yr$ during this study period. The seasonal averaged pH in leaves were spring pH 5.9 0.5, summer pH 5.5 0.4 and fall pH 5.1 0.3. The seasonal average water soluble sulfur content in leaves were spring 0.012 0.004%, summer $0.012\;0.002\%\;and\;fall\;0.020\;0.007\%$. The seasonal average water soluble sulfur content in bark were spring $0.0071\;0.0003\%,\;summer\; 0.0066\;0.0004\%,\;fall\;0.0063\;0.0004\%\;and\;winter\;0.0071\;0.0003\%$.

• Land and Housing Review
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• v.2 no.4
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• pp.517-528
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• 2011

Indiscreet developments cause environmental problems in major cities of Seoul Metropolitan Area. Among the environmental problems, the air pollution leads the citizens' physical and economic damages. Therefore, it needs to predict how much air pollutant which is emitted from human activities can be carried by urban environment, then to examine the reasonable level of urban development This study assumed that the air pollution is represented differently by the amount of emission. With the assumption, the acceptable air pollutant emission which keeps the air quality under the environmental standard is estimated, then the proper population is calculated in the case of Gwacheon, Gyeonggi. The result is as follow: First, air pollution concentrations of CO, $NO_2$, $SO_2$ which are estimated by using IDW interpolation of GIS don't excess the air environmental standard. Second, the result of correlation analysis between air pollutant emission and air pollution concentration shows that CO and $NO_2$ has high correlationship with total source of pollution and linear source of pollution, and $SO_2$ with linear source of pollution. Third, the results of regression analysis show that the acceptable population is bigger that the real population in the case of CO, and with the estimation of $NO_2$ and $SO_2$, the current population in the urban center and boundaries where the residential and commerce land uses are concentrated is bigger than the acceptable population. The consequence of this study is that the estimation of carrying capacity can suggest the acceptable human activities which keep the air quality under the environmental standard. This can leads the sustainable urban development by control the human activities under the carrying capacity of urban environment.

• Journal of Preventive Medicine and Public Health
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• v.19 no.2 s.20
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• pp.252-262
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• 1986

In order to assess the degree of atmospheric pollution and to contribute the health improvement of residents in Pusan, the authors measured CO, $SO_2,\;NO_2$ and TSP level at 3 places by season and time from July, 1985 to April, 1986. The places were Somyon, Sasang and Daeshin-dong, which were known as the commercial, industrial and residental area in Pusan, respectively. The obtained results were as follows: 1) The average concentration of CO was highest with $2.19{\pm}0.52$(3.5-1.0)ppm at Sasang area, and lowest with $1.32{\pm}0.55$(3.0-0.5)ppm at Daeshin-dong areas. 2) The average concentration of $SO_2$ was highest with $0.092{\pm}0.073$(0.378-0.028)ppm at Sasang, and lowest with $0.041{\pm}0.014$(0.083-0.019)ppm at Daeshin-dong. 3) The average concentration of $NO_2$ was highest with $0.069{\pm}0.012$(0.090-0.050)ppm at Somyon, and lowest with $0.043{\pm}0.010$(0.061-0.032)ppm at Daeshin-dong. 4) The average concentration of TSP was highest with $300{\pm}130(780-130){\mu}g/m^3$ at Sasang, and lowest with $160{\pm}80(390-70){\mu}g/m^3$ at Daeshin-dong. 5) The level of CO and TSP were highest in summer at Somyon and Daeshing-dong, and in winter at Sasang, respectively. The level of $SO_2$ and $NO_2$ were highest in winter and spring at all areas. 6) The level of all air pollutants were higher in the afternoon or night than in the morning.

• Clean Technology
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• v.27 no.4
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• pp.367-371
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• 2021

The oxy-combustion system is one of the carbon recovery and storage technologies (CCS: Carbon capture & storage) that performs coal combustion using pure oxygen and recirculated flue gas. This is a technology that facilitates storage of carbon dioxide by generating an exhaust gas consisting of only carbon dioxide without a process of separating carbon dioxide and nitrogen when coal is burned using pure oxygen and recirculated flue gas mixture instead of a conventional air combustion system that produces carbon dioxide and nitrogen mixed exhaust gas. In this study, the characteristics of generated NO and SO₂ as atmospheric pollutants during oxy-combustion were examined using O₂/CO₂ mixed simulation gas. The reaction temperature was varied from 900 ℃ to 1200 ℃ and oxygen partial pressure was varied from 30% to 50%. The results showed that NO and SO₂ concentrations in flue gas increased as the oxygen concentration and the reaction temperature in the furnace increased. The partial pressure of CO₂ in flue gas also increased as the oxygen concentration and the reaction temperature in the furnace increased. As a results of comparing NO production of 30% O₂/CO₂ oxy-combustion with air combustion, NO in flue gas increased with reaction temperature in both experiments and NO of oxy-combustion was 40 ~ 80 ppm lower than that of air combustion.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1739-1756
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• 2021

Atmospheric nitrogen dioxide (NO₂) is mainly caused by anthropogenic emissions. It contributes to the formation of secondary pollutants and ozone through chemical reactions, and adversely affects human health. Although ground stations to monitor NO₂ concentrations in real time are operated in Korea, they have a limitation that it is difficult to analyze the spatial distribution of NO₂ concentrations, especially over the areas with no stations. Therefore, this study conducted a comparative experiment of spatial interpolation of NO₂ concentrations based on two linear-regression methods(i.e., multi linear regression (MLR), and regression kriging (RK)), and two machine learning approaches (i.e., random forest (RF), and support vector regression (SVR)) for the year of 2020. Four approaches were compared using leave-one-out-cross validation (LOOCV). The daily LOOCV results showed that MLR, RK, and SVR produced the average daily index of agreement (IOA) of 0.57, which was higher than that of RF (0.50). The average daily normalized root mean square error of RK was 0.9483%, which was slightly lower than those of the other models. MLR, RK and SVR showed similar seasonal distribution patterns, and the dynamic range of the resultant NO₂ concentrations from these three models was similar while that from RF was relatively small. The multivariate linear regression approaches are expected to be a promising method for spatial interpolation of ground-level NO₂ concentrations and other parameters in urban areas.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.283-295
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• 2011

Many actions against climate change have been taken to reduce greenhouse gases (GHGs) emissions at home and abroad. As of 2007, the GHGs emitted from buildings accounted for about 23 % of Korea's total GHGs emission, which is the second largest GHG reduction potential following industry. In this study, we introduced Carbon Zero Building (CZB), which was constructed by the National Institute of Environmental Research to cut down GHGs from buildings in Korea, and evaluated the main applied technologies, the amount of energy load and reduced energy, and economic values for CZB to provide data that could be a basis in the future construction of this kind of carbon-neutral buildings. A total of 66 technologies were applied for this building in order to achieve carbon zero emissions. Applied technologies include 30 energy consumption reduction technologies, 18 energy efficiency technologies, and 5 eco-friendly technologies. Out of total annual energy load ($123.8kWh/m^2$), about 40% of energy load ($49kWh/m^2$) was reduced by using passive technologies such as super insulation and use of high efficiency equipments and the other 60% ($74.8kWh/m^2$) was reduced by using active technologies such as solar voltaic, solar thermal, and geothermal energy. The construction cost of CZB was 1.4 times higher than ordinary buildings. However, if active technologies are excluded, the construction cost is similar to that of ordinary buildings. It was estimated that we could save annually about 102 million won directly from energy saving and about 2.2 million won indirectly from additional saving by the reduction in GHGs and atmospheric pollutants. In terms of carbon, we could reduce 100 ton of $CO_2$ emissions per year. In our Life Cycle Cost (LCC) analysis, the Break Even Point (BEP) for the additional construction cost was estimated to be around 20.6 years.

• Clean Technology
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• v.28 no.2
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• pp.131-137
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• 2022

The semiconductor process currently emits various by-products and unused gases. Emissions containing pollutants are generally classified into categories such as organic, acid, alkali, thermal, and cabinet exhaust. They are discharged after treatment in an atmospheric prevention facility suitable for each exhaust type. The main components of organic exhaust are volatile organic compounds (VOC), which is a generic term for oxygen-containing hydrocarbons, sulfur-containing hydrocarbons, and volatile hydrocarbons, while the main components of alkali exhaust include ammonia and tetramethylammonium hydroxide. The purpose of this study was to determine the combustion characteristics and analyze the NO_X reduction rate by maintaining a direct combustion and temperature to process organic and alkaline exhaust gases simultaneously. Acetone, isopropyl alcohol (IPA), and propylene glycol methyl ether acetate (PGMEA) were used as VOCs and ammonia was used as an alkali exhaust material. Independent and VOC-ammonia mixture combustion tests were conducted for each material. The combustion tests for the VOCs confirmed that complete combustion occurred at an equivalence ratio of 1.4. In the ammonia combustion test, the NO_X concentration decreased at a lower equivalence ratio. In the co-combustion of VOC and ammonia, NO was dominant in the NO_X emission while NO₂ was detected at approximately 10 ppm. Overall, the concentration of nitrogen oxide decreased due to the activation of the oxidation reaction as the reaction temperature increased. On the other hand, the concentration of carbon dioxide increased. Flameless combustion with an electric heat source achieved successful combustion of VOC and ammonia. This technology is expected to have advantages in cost and compactness compared to existing organic and alkaline treatment systems applied separately.