• Asian Journal of Atmospheric Environment
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• v.9 no.3
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• pp.222-227
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• 2015

The environmental education with ideal teaching tools (e.g., a small-scaled experimental kit) is essential for raising the public's, especially student's, awareness of many environmental issues. This study was undertaken to develop a do-it-yourself model instrument of acid rain and estimating its applicability to the environmental education. Our novel model tool consists of a body (17 cm width, 6 cm depth, and 17 cm height), an acid gas injector, acid four rain reservoirs, and a drop supply pump. An alternative model instrument that can be more readily assembled was also suggested. Based on our novel approach, we carried out several model experiments with educatees (i.e., high school and college students, and adults). The results of questionnaires indicated that educatees achieved a very deep understanding of acid rain through an experienced model experiment. A 77 to 89% of educatees experienced the reappearance experiment of acid rain by our model instrument felt that it was very useful as a teaching tool of environmental education.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.2
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• pp.191-204
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• 2003

A one dimensional time dependent acid rain model considering size distribution of aerosols and hydrometeors is developed to predict observed chemical and physical properties of precipitation. Temporal variations of anions and cations observed are predicted fairly well with acid rain model simulations. It is found that aerosol depletion rates are highly dependent on aerosol sizes under the assumption of Marshall - Palmer raindrop size distribution. Also, the aerosol depletion during the initial rain event largely influences on ion concentrations in rainwaters.

• The Korean Journal of Ecology
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• v.19 no.1
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• pp.71-80
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• 1996

The effects of simulated acid rain on the growth and interspecific competition of Echinochloa crus-galli and Digitaria sanguinalis were studied. Changes of growth in height and dry weight were examined and competition between the two species was investigated using the experimental model proposed by de Wit (1960). The experiments were carried out in the greenhouse, and test plants were germinated and grown for 4 weeks and then sprayed with simulated acid rain of pH 5.6, 4.2 and 2.8 for another 8 weeks. In de Wit replacement experiments, the variation of density and the treatment of simulated acid rain showed little effect on the interspecific competition between E. Crus-galli and D.sanguinalis. The ratio diagram, another method to reveal the interrelations between two competing species, always showed the predominance of E. crus-galli in competition, regardless of density and pH. The interspecific competition of the two species, represented by relative yield total (RYT), revealed that intraspecific competition was stronger than interspecific competition in both species.The treatment of simulated acid rain showed little effect on the growth of E. Crus-galli and D. sanguinalis. Height growth of both species did not differ from that of control (pH 5.6), but root/shoot ratio increased with the decrease in pH of simulated acid rain. Growth of tatal dry weight of E. crus-galli and D. sanguinalis was not influenced by the change of pH, except that D.sanguinalis showed a decrease in the total dry weight at pH 2.8 along with a visible sign of white spots on leaves. Physical environmental conditions can exert an effect on the interrelationships between the two species, but this experiment did not show the reversion of competition, and showed that E.crus-gilli was competitively dominant under any environmental conditions given in this study.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.93-102
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• 1997

Acid rain below pH 5.6 is responsible for 40% of annual precipitation in Korea and it is more serious especially in major cites. Because of that, it is urgent to make measures to reduce the emission of $SO_2$, one of the major air pollutants causing acid rain. The national total emission of $SO_2$ in 1994 was estimated as 1.6 million tons. The $SO_2$ emission in 2020, is expected to increase up to 3.2 million tons, about 2 times that of 1994 under Business-As-Usual scenario. We could take various $SO_2$ reduction measures such as installing desulfurization facilities, the supply of low-sulfur oil and clean fuel(LNG), energy savings, upgrading of production process. However, it is necessary to check the economic feasibility and the attainability to reduction target with a dynamic optimization mode, "Global 2100 Model". The cost-benefit analyses for the measures using the revised "Global 2100 Model" clearly revealed that the desulfurization facilities should be introduced to reduce the $SO_2$ concentration to 0.01 ppm with fuel substitution. If the introduction of desulfurization facilities is delayed, We can not attain the goal of Ministry of Environment before the year of 2012, even in the case that almost all the fuels would be substituted with LNG.

• Geomechanics and Engineering
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• v.29 no.5
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• pp.549-565
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• 2022

Severe acid rains can be a major source for geotechnical and environmental problems in any soil depending on the acid type and concentration. Hence, this study investigates the individual severe effects of sulfuric, hydrochloric and nitric acids on the geotechnical properties of real field soil through a series of experimental laboratory tests. The laboratory program consists of experimental tests such as consistency, compaction, unconfined compression, pH determination, electrical conductivity, total dissolved salts, total suspended solids, gypsum and carbonates contents. The experimental tests have been performed on the untreated soil and individual acid treated soil for acid concentrations range of 0% to 20% by weight. In addition, a unique hyperbolic mathematical model has been used to predict significant geotechnical characteristics for acid treated soil. The plastic and liquid limits and optimum moisture content have been increased under the effect of all the used acids whereas the maximum dry density and unconfined stress-strain behavior have been decreased with increasing the acid concentrations. Moreover, the used hyperbolic mathematical model has predicted all the geotechnical characteristics very well with a very high coefficient of determination (R²) value and lowest root mean square error (RMSE) estimate.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.2
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• pp.66-74
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• 1986

Rain samples were collected at 10 sites in the Seoul area during the period of August through November, 1985. THe concentrations of the major cations $(H^+, Ca^{++}, MG^{++}, Na^+, K^+, NH_4^+)$ and the major anions $(SO_4^=, NO_3^-, Cl^-)$ were measured to characterize the main sources of chemical ions in rainwater. Correlating concentrations of ions to pH, calculated coefficients ranged from 0.1485 to 0/4296. Sulfate shows the largest coefficient indicating that sulfate is more closely associated with hydrogen ion than other ions. This may suggest that sulfuric acid contributes more to the acidity of rainwater in Seoul. It appears that the major chemicals measured in rainwater are from the anthropogenic sources of air pollution. Predominant chemicals are acidic at the Guro-, the Sinseol-, the Yangnam-, and the Ssangmun-dong with sulfate being the most predominant. IT also indicates that alkaline substances resulting from soil and dust have a significant effect on pH values of rainwater by neutralizing actions. According to Granat-model analysis, it is estimated that the relative contributions to the rainwater acidity in Seoul are 84% from sulfuric acid, 8% from nitric acid and 8% from hydrochloric acid.

• Journal of Environmental Impact Assessment
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• v.8 no.1
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• pp.29-40
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• 1999

This study focuses on one of typical energy-intensive industries, the cement industry. The purpose of the study is to propose $SO_2$ emission reduction measures in the cement industry. This study partially employed and modified AIM(Asia-Pacific Integrated Model) developed by Japan National Environmental Research Institute to develop AIM/KOREA SULFUR model for simulation. In the study, a base scenario, and mitigation scenarios(a use of low-sulfur contain fuel, fuel conversion to cleaner energy, an induction of desulfurization systems, and energy saving) were employed. The results of the simulation are summarized below: The sulphur dioxide emission from the cement industry in 1992 was estimated to be 106,000 metric tons; however, according to base scenario, sulphur dioxide emission is expected to be increased to 219,000 metric tons, which is 2.1 times greater than that in 1992 by year 2020. To alleviate such increasement, simulation results under various scenarios proved that some degrees of reduction may be possible by an induction of desulfulization systems although there may be numerous ways to interpretate the simulation results.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.71-82
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• 1998

This study focuses on one of the most typical energy-intensive industries, the steel industry. The two-fold purpose of the study is to develop a model to assess measures to alleviate sulfur dioxide($SO_2$) emissions from the steel industry and to propose a concrete $SO_2$ emission reduction measure from the steel industry. This study partially employed and modified AIM(Asia-Pacific Integrated Model) developed by Japan National Environmental Research Institute to develop AIM/KOREA SULFUR model for simulation. In the study, a base scenario, which is BAU(Business As Usual) scenario, and mitigation scenarios(a use of low-sulfur contain fuel, fuel conversion to cleaner energy, an induction of desulfurization systems, and energy saving) were employed. The results of the simulation are summarized below: The sulphur dioxide emission from the steel industry in 1992 was estimated to be 252,000 metric tons; however, according to BAU scenario, sulphur dioxide emission is expected to be increased to 586,000 metric tons, which is 2.3 times greater than that in 1992 by year 2020. To alleviate such increasement, simulation results under various 7scenarios proved that some degrees of reduction may be possible by an induction of desulfurization systems although there may be numerous ways to interpretate the simulation results; however, the bottom line is that it appears to be difficult to achieve the Korean Ministry of Environment's policy goal-a mitigation of sulphur dioxide concentration to 0.01ppm.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.517-520
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• 2001

Fossil fuels such as coal and crude oil contain various organic sulfur compounds. Combustion of these fuels emit sulfur oxides which are considered as msjor air pollutants causing acid rain problem. Among various organic sulfur compounds, aromatic sulfur compounds of thiophenes which constitute major sulfur fractions of heavy oils are not easily removed by hydrodesulfurization. Many peroxidase and hemoproteins are known to oxidize dibenzothiophene (DBT) to dibenzothiophene-sulfoxide(DBT - sulfoxide) then dibenzothiophene- sulfone (DBT-sulfone). The oxidation of DBT by the immobilized hemoproteins in n-octane was increased significantly when the hemoproteins were deposited on celites of the particle size between 0.75 - 1.0 mm and a conventional substrates. such as t-butyl hydroperoxide and cumene hydroperoxide. In anhydrous organic solvents with log P values larger than 4.0 DBT was completely oxidized by cumene hydroperoxide catalyzed by cytochrome c deposited on celites.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.1
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• pp.43-51
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• 1989

개발된 산성비 모델에서는 다종의 대기오염물 제거로 인한 강우내의 화학성분과 산성도의 고도별 및 시간별 변화를 예측하기 위하여, 강우시 구름내와 밑에서 일어나는 대기 오염물의 강우내로의 물질전달 현상과 화학반응 현상을 동시에 고려하였다. 또한, 강우 산성도의 형성에 중요한 영향을 미치는 구름내에서의 복잡한 동력학적 특성을 고려하기 위하여 강우율의 높이별 변화를 단순화하여 해석하였다. 개발모델을 이용하여 1985년과 1987년 가을의 서울시 산성비에 대하여, 산성비 모델을 이용하여 추정한 pH값과 실측 pH값 사이의 상관관계는 0.57을 나타내었고, 효과적이고 정량적인 관리를 위하여 대기중의 이산화황 농도, 구름층의 두께, 지상에서의 강우율 및 황산이온의 형성에 중요한 역활을 하는 산화제들의 강우 산성도에 미치는 영향을 민감도 분석을 통해서 나타내었다.