• Journal of Environmental Impact Assessment
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• v.8 no.4
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• pp.73-79
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• 1999

This study was conducted as a preliminary study for the mitigation of acid rain which has been a serious environmental problem in both regional and global scales. In this study, sulfur dioxide emission was estimated at city and gun(county) level. Also, this study represents the estimated sulfur dioxide emission with using a geographical information system which includes administrative boundaries. The results of this study are expected to serve as a sulfur dioxide emission mitigation policy guidance and a basis of a future emission model and a comprehensive global warming model. Moreover, thanks to the geographical information system, the results are also expected to help carrying out clear policy goals and setting up sulfur dioxide emission mitigation measures in regional environmental planning processes, which currently have been implemented in some cities and counties in Korea.

• Journal of Industrial Technology
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• v.39 no.1
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• pp.41-45
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• 2019

Hydrogen sulfide ($H_2S$) is mainly produced along with methane and hydrocarbons in many gas fields as well as hydrodesulfurization processes of crude oils containing sulfur compounds and the emission of $H_2S$ has a considerable effect on both environmental problem and human health aspects due to formation of, e.g. acid rain and smog. In recent years, ionic liquids (ILs) have been proposed as the most promising solvents for $CO_2$ and hazardous pollutants capture, such as $H_2S$ and sulfur dioxide ($SO_2$). In this work, we demonstrate the use of the predictive COSMO-SAC model for the prediction of Henry's law constant of $H_2S$ in ILs. Furthermore, the method is used to screen for potential IL candidates for $H_2S$ capture from a set of 2,624 ILs formed from 82 cations and 32 anions. The effects of cation on the Henry's law constant of $H_2S$ such as (i) the variation of the alkyl chain length on cation, (ii) the substituent of methyl group ($-CH_3$) for H in C(2) position and (iii) the change of ring structure for cation family are clearly predicted by COSMO-SAC model.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.55-63
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• 1998

This study investigates the contamination mechanism of soil by drainages including acid rains around mining waste sites, and suggests the quantitative methods of prevention against soil contaminations and its alternatives. For these purposes, the dissolution of arsenic in soils, which is one of toxic heavy metals, has been examined experimentally using the artificial acidic solution. Also, in order to prevent dissolution of arsenic by acid rain, the effects of limestone for the neutrality method on the soil were investigated. The arsenic in soil specimen was dissolved by strong acidic solution below pH1.0. The maximum amount of dissolved arsenic increased with decreasing pH value. Furthermore, it was found very effective to use limestones for the neutrality method. The neutralization of limestones in acidic solution was found to follow the equation of chemical reaction-controlling formulation in unreacted-core models.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.2
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• pp.121-127
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• 1992

This study was carried out to investigate the features of air pollutants in rainwater and trace their transported trajectories from other countries. Chemical analysis data of rainwater and suspended particulates collected at Seoul, Kanghwa, and Taean for three years were used to evaluate the effects of long-range transport of air pollutants. Scavenging theory on washout and rainout effect during a rainy period was applied to estimate whether pollutants in the precipitation were long-range transported or not. On the other hand, precipitation weighted surface wind were evaluated to analyze the effect from local sources on atmospheric concentrations. As a result, contribution of air pollutants caused by anthropogenic sources in the precipitation which was identified to be long range transported was confirmed significantly high and trajectory of these pollutants was to be equivalent to 850mb isobar. Although concentration of acidifying components increased in the precipitation, neutralization by alkaline soil components such as $Ca^{2+}$ and $Mg^{2+}$ was conspicuous especially during Yellow-sand period.

• Journal of environmental and Sanitary engineering
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• v.8 no.2
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• pp.25-48
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• 1993

International concern over the environmental pollution is ever increasing, and diversified countermeasures must be devised in Korea also. Global trend, damages, problems and countermeasures with respect to issues mentioned in the Rio Declaration, such as prevention of ozone layer destruction, reduction of migratory atmospheric pollution between neighboring countries, and prevention of global greenhouse effect, were discussed in this report. Conclusion of the report is summarized as follows : A. Measurement, Planning and Monitoring (1) Development and implementation of a global network for measurement and monitoring from the global aspects such factors as related to acid rain(Pioneer substances, pH, sulfate, nitrate), effect of global temperature(Air temperature, $CO_2$, $CH_4$, CFC, $N_2O$) and destruction of ozone layer($CFC_S$). (2) Establishment of network system via satellite monitoring movement of regional air mass, damage on the ozone layer and ground temperature distribution. B. Elucidation of Present State (1) Improvement and development of devices for carbon circulation capable of accurately forecasting input and output of carbon. (2) Developmental research on chemical reactions of greenhouse gas in the air. (3) Improvement and development of global circulation model(GCM) C. Impact Assessment Impact assessment on ecosystem, human body, agriculture, floodgate, land use, coastal ecology, industries, etc. D. Preventive Measures and Technology Development (1) Development and consumption of new energy (2) Development of new technology for removal of pioneer substances (3) Development of substitute matter for $CFC_S$ (4) Improvement of agriculture and forestry means to prevent the destruction of ozone layer and the greenhouse effect of the globe (5) Improvement of housing to prevent the destruction of ozone layer and the greenhouse effect of the globe (6) Development of new technology for probing underground water (7) Preservation of forest (8) Biomass 5. Policy Development (1) Development of strategy model (2) Development of long term forecast model (3) Development of penalty charge effect and expense evaluation methods (4) Feasibility study on regulations By establishing the above mentioned measures for environmentally sound and sustainable development to establish the right to live for humankind and to preserve the one and only earth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.1-10
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• 2022

Exhaust gases emitted from internal combustion engines contain nitrogen oxides (NOx) and sulfur oxides (SOx), which are major air pollutants causing acid rain, respiratory diseases, and photochemical smog. As a countermeasure, scrubber systems are being studied extensively. In this study, the pressure drop characteristics were analyzed by changing the exhaust gas inflow velocity using a scrubber for a 700 kW engine as a model. In addition, the fluid flow inside the scrubber and the behavioral characteristics of the droplets were studied using CFD, and the design compatibility of the cleaning device was verified. Flow analysis was performed using inertial and viscous resistances by applying porous media to the complex shape of the scrubber. The speed of the exhaust passing through the outlet nozzle from the inlet was determined through the droplet behavior analysis by spraying, and the flow characteristics for the pressure drop were studied. In addition, it was confirmed through computational analysis whether there was a stagnation section in the exhaust gas flow in the scrubber or the sprayed droplets were in good contact with the exhaust gas.