• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1028-1032
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• 2009

비교적 한정되고 정해진 구역에서 오염물질이 배출되는 것을 점오염이라고 하는 반면, 비점오염은 도시, 농지, 산지, 등 불특정 구역에서 오염물질을 발생시킨다. 점오염에 관한 오염관리가 체계적으로 시행되었던 이전과 달리 최근에는 비점오염에 대한 대책이 시급해짐에 따라 정부는 비점오염에 대한 중요성을 유념하여 한강수계를 대상으로 오염총량관리제를 시범적으로 실시하였다. 환경부는 기존 비점오염원 원단위 부하를 세분화 하여 오염총량제도의 정확도를 향상시키기 위해 노력하고 있다. 우리나라의 비점오염의 관한 연구 중 광산(탄광)지역의 관한 연구는 매우 적다. 본 연구는 광산(탄광)지역의 장기간의 유량 및 수질 모니터링을 통하여 계절별 배출되는 비점오염물질의 유량을 비교하고, ESTIMATOR 모델 방법으로 T-N과 T-P를 분석하였다. 본 연구를 통하여 광산(탄광)지역의 장기적인 모니터링 수행으로 비점오염부하 산정의 유용한 자료로 활용할 수 있을 것으로 판단된다.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.691-692
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• 2001

Until tile 1980s, the disposal of End of Life Vehicles (ELV) was considered unproblematic in Japan, Korea. and Taiwan. But in recent years, as environmental problems have attracted increasing attention. the processing oi ELV has become one of the most critical environmental issues. Discarded ELV represent a serious source of waste generation and pollution. In this paper, I will analyze the ELV problem from three view points: 1) ELV abandoned in the environment; 2) Significant environmental hazards caused by dismantling operations; and 3) Problems of how to deal with Automobile Shredder Residue (ASR).

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.12a
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• pp.97-101
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• 1996

Municipal and sanitary landfills can pose environmental problems due to leachate, landfill gas md unstable geotechnical properties. Most governmental bodies delay the correction of landfill problems or landfill replacement until a crises stage is reached. The replacement of a landfill is often made difficult due to costly regulatory controls, public opposition to siting and the high cost of closure for the previous landfill unit. Solutions to extending landfill life and capacity Involve waste minimization by recycling, refuse compaction and waste-to-energy incineration. Incineration can reduce the volume of refuse by 50-95%. The largest installed bases of municipal waste Incinerators are located in Japan and the U.S. The volume of waste contained in a landfill can be estimated by load count tabulations, weight-and-volume measurements or a material balance analysis based on the trash profile of user categories. for an existing landfill, core samples may be collected and analyzed for use in a material balance analysis. Newly generated refuse contains approximately 50% of the heating value of coal. However, landfill properties vary significantly due to the waste profile of the contributors and biodegradation due to time and weathering. The volume of the Nanji-do landfill

• Communications of the Korean Mathematical Society
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• v.9 no.2
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• pp.265-270
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• 1994

In 1966, Iseki [2] introduced the notion of BCI-algebras which is a generalization of BCK-algebras. Lei and Xi [3] discussed a new class of BCI-algebra, which is called a p-semisimple BCI-algebra. For p-semisimple BCI-algebras, a subalgebra is an ideal. But a subalgebra of an arbitrary BCI/BCK-algebra is not necessarily an ideal. In this note, a BCI/BCK-algebra that every subalgebra is an ideal is called a normal BCI/BCK-algebra, and we give characterizations of normal BCI/BCK-algebras. Moreover we give a positive answer to the problem which is posed in [4].(omitted)

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.763-772
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• 2021

Drilling Mud Treatment Systems are widely used for Oil Gas drilling mud circulation, horizontal directional drilling mud recycling, geothermal drilling, mining, coal exploration drilling, water well drilling. Degasser is a device used in drilling to remove gasses from drilling fluid which could otherwise form bubbles. For small amounts of entrained gas in a drilling fluid, the degasser can play a major role of removing small bubbles that a liquid film has enveloped and entrapped. As with the desander, its purpose is to remove unwanted solids from the mud system. The smaller cones allow the desilter to efficiently remove smaller diameter drill solids. In this study, a simulation study is conducted on the degasser of the facility in the Mud Treatment System to conduct a performance review on the gas separation in the mud.

• Korean Journal of Remote Sensing
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• v.38 no.4
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• pp.365-374
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• 2022

Mining activity causes environmental pollution and geological hazards such as ground subsidence or landslide of which continuous monitoring is necessary. In this study, the activity on the Fushun West Open-Pit Mine (FWOPM), one of the largest open-pit coal mines in Asia located in Fushun, Liaoning Province, China, was analyzed by using a time-series Sentinel-1 InSAR coherence dataset. By using the difference between the two Digital Elevation Models (DEM) of the area, it was possible to confirm that there was a stockpiling activity in the western area of the FWOPM while excavation activity in the eastern area. By using RGB composite images using the yearly-averaged InSAR coherence images, the activity of the mine was confirmed by period, which was confirmed by Google Earth optical images. As a result, it was possible to confirm three landslides and the related activities on the northwest slope and the dumping activity on the west slope of FWOPM.

• Economic and Environmental Geology
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• v.40 no.3 s.184
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• pp.295-306
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• 2007

In this study, we predicted areas vulnerable to ground subsidence near abandoned underground coal mine at Sam-cheok City in Korea using a probability (frequency ratio) model with Geographic Information System (GIS). To extract the factors related to ground subsidence, a spatial database was constructed from a topographical map, geo-logical map, mining tunnel map, land characteristic map, and borehole data on the study area including subsidence sites surveyed in 2000. Eight major factors were extracted from the spatial analysis and the probability analysis of the surveyed ground subsidence sites. We have calculated the decision coefficient ($R^2$) to find out the relationship between eight factors and the occurrence of ground subsidence. The frequency ratio model was applied to deter-mine each factor's relative rating, then the ratings were overlaid for ground subsidence hazard mapping. The ground subsidence hazard map was then verified and compared with the surveyed ground subsidence sites. The results of verification showed high accuracy of 96.05% between the predicted hazard map and the actual ground subsidence sites. Therefore, the quantitative analysis of ground subsidence near abandoned underground coal mine would be possible with a frequency ratio model and a GIS.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.112-118
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• 2012

Fine suspended solids from mine drainage draw attentions due to their potential adverse influences on the water quality, such as increasing turbidity and degrading aesthetic landscape. Currently, sand filter beds are adapted in some mine drainage treating systems. However, more efficient system is in demand, as the existing sand beds reveal some problems, such as frequent maintenance intervals. Various filtering mediums including fly ash, mine tailing aggregates and the sand were tested for improving the current system, using column experimental set-up. Mine drainage samples were collected from the current treating systems in the abandoned H coal mine. The experiment was run for 7 days. Suspended solids recorded as 100.9 mg/L and the value exceeds the current standard, 30 mg/L. Sand was proved to still be the optimum medium for the fine suspended solids, compared to fly ash and fly ash + sand. Mine tailing aggregates were placed at the exit of the columns, substituting gravels. The tailing aggregates is made by mine tailings and clay. Sand bed filters can also be improved by mixing granular activated carbon, which was found to be economical and efficient in the batch experiment, conducted at the same time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1480-1487
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• 2012

Recently, the safety of the coal-mining tunnels has been improved greatly, but accidents occur continually. Most tunnel support failures occur because the fish plate part that connects the I-beams is unable to withstand ground pressure. In the case of XX coal mine, the arch part of tunnel support bends to the upper direction. In such a case, excessive horizontal load as well as vertical load acts on the tunnel support. Horizontal load is caused by the sudden loosing of underground rock mass or the leakage of underground water, so it is fairly complex to predict horizontal loading on a tunnel support. To predict the horizontal load on this component is defined as the problem that determines the horizontal load conditions in wedges of tunnel support. This is an optimization problem in which maximum bending stress and horizontal load are considered by an objective function and design variables, respectively. Therefore, in this study, design of experiments and optimization algorithm were applied to identify the horizontal load in tunnel support.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.2
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• pp.179-189
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• 2006

Ambient gas phase mercury concentrations including elemental mercury ($Hg^0$) were measured at the Potsdam, Stockton, and Sterling sites in NY from 2000 to 2003. Also, concentrations of ambient reactive gaseous mercury (RGM; $Hg^{2+}$) were measured at the Potsdam site during one year. The contribution of RGM($4.2{\pm}6.4pg/m^3$) was about $0.2{\sim}3%$ of the total gas phase mercury concentration measured (TGM: $1.84{\pm}1.24,\;1.83{\pm}0.32,\;3.02{\pm}2.14ng/m^3$ in Potsdam. Stockton, and Sterling, respectively) at the receptor sites. Potential Source Contribution Function (PSCF), a hybrid receptor modeling incorporating backward trajectories was performed to identify source areas of TGM. Using PSCF, southern New York, North Carolina, and eastern Massachusetts were identified as important source areas in the United States, while the copper smelters and waste incinerators located in eastern Quebec and Ontario were determined to be significant sources in Canada. The Atlantic Ocean was suggested to be a possible mercury source. PSCF incorporating back-dispersion and deposition was applied for RGM , as well as PSCF based on 2-days back-trajectories. Two different approaches yielded considerably different results, primarily due to the consideration of dispersion rather than deposition. Using back-trajectory based PSCF, eastern Ohio, southern New York, and southern Pennsylvania where large coal -fired power plants area located were identified as the large sources in US. Metallurgical industry located in eastern Quebec was resolved as well. From the result of back-dispersion and deposition based PSCF, Pennsylvania, mining facilities around Lake Superior, Toronto, Boston, MA, Quebec, and coal power plants in NY were identified to be the significant source areas for Potsdam site.