• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.296-300
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• 2007

본 연구에서는 강원도 정선지역 및 삼척지역의 폐탄광 지역에서 관측된 지반침하지역의 공간자료와 각종 지반침하 관련요인을 분석하여, 지질학적구조와 지역적 특성이 상이한 지역에서 지반침하에 직접적인 영향을 주는 공통요인을 찾아내고자 하였다. 연구지역의 지반침하 관련요인들에 대해 GIS(Geographic Information System)를 이용하여 래스터 데이터베이스를 구축하고 모든 요인을 이용하여 분석한 위험지역과 하나의 요인씩 제거하며 분석한 위험지역을 비교하는 민감도 분석 (Sensitivity analysis)을 통해 지반침하와 연관성이 높은 요인을 추출하였다. 민감도 분석은 서로 다른 두 지역에 대해 수행하여 그 결과를 비교하였으며, 갱으로부터의 수평거리，RMR(Rock Mass Rating), 지하수 심도가 지반침하에 영향을 주는 공통요인으로 분석되었다. 본 연구결과, 폐탄광지역의 지반침하에 공통적으로 영향을 끼치는 주 요인을 구할 수 있었으며, 타 지역에서 지반침하 예측시 기존 연구에서 사용한 요인들의 데이터를 전부 구하지 못하는 경우에도 최소한의 필요한 요인을 정할 수 있으며 지반침하 예측의 효율성을 높일 수 있을 것이라 기대된다.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.301-304
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• 2007

본 연구에서는 폐탄광 지역에서 발생하는 지반침하에 영향을 주는 주요 요인들을 추출하기 위하여 다변량 통계분석 방법의 하나인 주성분분석(Principle Component Analysis : PCA)기법과 지리정보시스템 (Geographic Information System : GIS)을 이용하였다. 이를 위해 연구지역에서 수행한 지표지질조사， 정밀조사, 실내암석시험 등으로부터 취득된 자료를 데이터베이스로 구축하고, 지반침하 위험지역 분포를 공간적으로 해석할 수 있는 지질, 토지이용, 경사도， 지표로부터 지하 갱도까지의 심도, 갱도의 지표상 위치로부터의 수평거리, 지하수심도, 투수계수, RMR(Rock Mass Rating) 값을 분석대상으로 선정하였다. 각 요인들이 연구지역 전체에 걸쳐 분포하도록 GIS의 공간분석 기법의 하나인 표면분석(Surface Analysis), 버퍼링기법(Buffering) 및 내삽법(Interpolation)을 이용하여 래스터 데이터베이스로 구축하고 이로부터 추출된 자료들을 입력값으로 하는 주성분분석을 수행하였다. 주성분분석 결과 폐탄광 지역의 지반침하에 영향을 주는 주요인을 추출하는 것이 가능하였으며, 연구지역은 지질 및 지반강도 관련 요인이 침하발생의 가장 큰 요인인 것으로 분석되었다.

• Journal of Soil and Groundwater Environment
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• v.25 no.3
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• pp.12-22
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• 2020

Managed aquifer recharge (MAR) is a promising water management strategy for securing stable water resources to overcome water shortage and water quality deterioration caused by global environmental changes. A MAR demonstration site was selected at Imgok-ri, Sangju-si, Korea, based on screening for the frequency of drought events and local water supply situations. The abundant groundwater discharging from a nearby abandoned coal mine is one of the potential recharge water sources for the MAR implementation. However, it has elevated levels of arsenic (~12 ㎍/L). In this study, the potential of the natural attenuation of arsenic by the field geological media was investigated using batch and column experiments. The adsorption and desorption parameters were obtained for two drill core samples (GM1; 21.8~22.8 m and GM2; 26.0~27.8 m depth) recovered from the potentially water-conducting fracture-zones in the injection well. The effluent arsenic concentrations were monitored during the continuous flow of the mine drainage water through the columns packed with the core samples. GM2 removed about 60% of arsenic in the influent (0.1 mg-As/L) while GM1 removed about 20%. The results suggest that natural attenuation is an acitive process occurring during the MAR operation, potentially lowering the arsenic level in the mine drainage water below the regulatory standard for drinking water. This study hence demonstrates that using the mine drainage water as the recharge water source is a viable option at the MAR demonstration site.

• Journal of Soil and Groundwater Environment
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• v.27 no.4
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• pp.10-21
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• 2022

In the South Korea, 47% of abandoned mines are suffering from the mining hazards such as the mine drainage (MD), the mine tailings and the waste rocks. Among them the mine drainage which has a low pH and the high concentration of heavy metals can directly contaminate rivers or soil and cause serious damages to human health. The natural/artificial treatment facilities by using neutralizers and coagulants for the mine drainage have been operated in domestic and most of heavy metals in mind drainage are precipitated and removed in the form of metal hydroxide, alumino-silicate or carbonate, generating a large amount of mine drainage treated sludge ('MDS' hereafter) by-product. The MDS has a large surface area and many functional groups, showing high efficiency on the fixation of heavy metals. The purpose of this study is to develop a ingenious heavy metal stabilizer that can effectively stabilize arsenic (As) and heavy metals in soil by recycling the MDS (two types of MDS: the acid mine drainage treated sludge (MMDS) and the coal mine drainage treated sludge (CMDS)). Various analyses, toxicity evaluations, and leaching reduction batch experiments were performed to identify the characteristics of MDS as the stabilizer for soils contaminated with As and heavy metals. As a result of batch experiments, the Pb stabilization efficiency of both of MDSs for soil A was higher than 90% and their Zn stabilization efficiencies were higher than 70%. In the case of soil B and C, which were contaminated with As, their As stabilization efficiencies were higher than 80%. Experimental results suggested that both of MDSs could be successfully applied for the As and heavy metal contaminated soil as the soil stabilizer, because of their low unit price and high stabilization efficiency for As and hevry metals.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.20-27
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• 2001

Stream water chemistry in the abandoned Boeun Jeil coal mine area was studied for a period of 3 months, including rainy and dry season. The stream waters were a nearly neutral and slightly alkali condition, and $Mg-SO_4$ type with Mg>Ca>Na>K and $SO_4>HCO_3>Cl>NO_3$. Chemical composition of the stream water was quite irregular during the experimental period. Concentrations of Na, K, $HCO_3$, U, Sr, and Cr decreased by $10{\sim}30%$ during rainy season, caused by dilution effects with rain. The concentration of Ca, Mg, $NO_3$, Cd, and Co increased during the rainy season, caused by more easily dissolved from bedrocks or mine drainage with slightly acidic condition than dry season. The stream water was enriched in Mg, Ca, $HCO_3$, $SO_4$, Al, Fe, Zn, Ni, Co, Cr, Cd, Sr and U. Concentrations of Na, Mg, Ca, $SO_4$, $HCO_3$, Fe, Zn, Ni, Sr, and U decreased linearly with distance from the mine adit. These elements were strongly controlled by dilution of unpolluted water influx and/or adsorption on the clay minerals and iron oxyhydroxide precipitates. This mine area exhibited two main weathering processes ; 1) oxidation with acidification derived from Fe sulphides, and 2) pH buffering due to Ca and Mg carbonate dissolution. This weathering processes were followed by adsorption of metals on iron oxyhydroxides and precipitation.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.372-380
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• 2007

Surface damage due to subsidence is an inevitable consequence of underground mining, which may be immediate or delayed for many years. The surface damage due to abandoned underground mine is observed to be two subsidence types such as simple sinkhole or trough formation to a large scale sliding of the ground from with in the subsided area. An evaluation of the risk of a subsidence occurrence is vital in the areas affected by mining subsidence. For a subsidence prediction or a risk evaluation, there has been used various methods using empirical models, profile functions, influence functions and numerical models. In this study, a simple but efficient evaluation method of subsidence hazard is suggested, which is based on a diffusion theory and uses just information about geometry of caving and topography. The diffusion model has an analogous relationship with granular model which can explain a mechanism of subsidence. The diffusion model is applied for the evaluation of subsidence hazard in abandoned metal and coal mines. The model is found to be a simple but efficient tool because it needs information of geometry of caving and gangway and the topography.

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.41-45
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• 2007

It is very important that selection of packing media with large surface area, high limited back pressure in biofilter. The object of this study is the isolation of sulfur-oxidizing bacteria and the removal of hydrogen sulfide in biofilter by media. This investigation led to the following results: 1) we isolated Thiobacillus sp. IW. at an abandoned coal mine in Hwasun, Jeonnam Province. 2) The inorganic media showed better results than the organic media from experiments looking at removal characteristics and changes in pressure drop using various media. 3) Among the inorganic media, fibril and PU media showed best performance.

• Ecology and Resilient Infrastructure
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• v.8 no.4
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• pp.290-298
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• 2021

This study was conducted to evaluate the possibility of applying phytoremediation technology by investigating soil and native plants in waste coal landfills exposed to heavy metal contamination for a long period of time. The ability of native plants to accumulate heavy metals using greenhouse cultivation experiments was alse evaluated. Plants were investigated at an abandoned coal mine in Hwajeolyeong, Jeongseon, Gangwon-do. Two species of native plants (Carex breviculmis. R. B. and Salix koriyanagi Kimura ex Goerz.) located in the study area and three Korean native plants (Artemisia japonica Thunb. Hemerocallis hakuunensis Nakai., and Saussurea pulchella (Fisch.) Fisch.) were cultivated in a greenhouse for 12 weeks in artificially contaminated soil. Soils contaminated with arsenic and lead were generated with arsenic concentration gradients of 25, 62.5, 125, and 250 mg kg^-1 and lead concentration gradients of 200, 500, 1000, and 2000 mg kg^-1, respectively. Results showed that none of the five plants could survive at high arsenic concentration treatment (125 and 250 mg kg^-1) and some plants died in 2000 mg kg^-1 lead concentration treatment soil. The plant translocation factor (TF) was highest in H. hakuunensis in arsenic treatments, and A. japonica in lead treatments, respectively. The bioaccumulation factor (BF) of plants was more than 1 in all species in arsenic treatment, whereas it was highest in H. hakuunensis. BF for all species was less than 1 in lead treatment. Particularly, in 2000 mg kg^-1 concentration lead treatment, A. japonica accumulated more than 1000 mg kg^-1 lead and was expected to be a lead hyperaccumulator. In conclusion, A. japonica and H. hakuunensis were excellent in the accumulation of arsenic heavy metals, and S. koriyanagi was excellent in lead accumulation ability. Therefore, the above mentioned three plants are considered to be strong contenders for application of the phytoremediation technology.

• Economic and Environmental Geology
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• v.29 no.3
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• pp.315-323
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• 1996

An apatite drain was constructed on September 30, 1994 at the Green Valley Abandoned Coal Mine site near Terre Haute in west central Indiana. The primary objective of this experiment is to evaluate the long-term ability of the apatite drain to mitigate acid mine drainage (AMD) under field conditions. The drain 9 m long, 3.3 m wide, and 0.75 m deep, contain 95 rum to No. 30 mesh-size apatite ore (francolite) and receive AMD seepage from reclaimed gob piles, and designed according to the laboratory testing. The apatite drain was covered with limestone riprap and filter fabric to protect the drainage system from stormwater and siltation. The drain consists of about 50 metric tons of apatite ore obtained from a phosphate mine in Florida. A gabion structure was constructed downstream of the apatite drain to create a settling pond to collect precipitates. Apatite effectively removed iron up to 4,200 mg/l, aluminum up to 830 mg/l and sulfate up to 13,430 mg/l. The pH was nearly constant for the influent and effluent, ranging between 3.1 and 4.3. Flow rate measured at the gabion structure ranged from 3 to 4.5 l/m. Precipitates of iron and aluminum phosphate (yellow and white suspendid solids) continued to accumulate in the settling pond.

• Economic and Environmental Geology
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• v.51 no.4
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• pp.371-379
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• 2018

In many countries, recycling coal ashes as backfill materials for subsided lands, abandoned mine tunnels, and road pipeline constructions by making low-strength concretes with minimal amounts of cement is frequently considered for massive treatment of coal ashes. This study investigates the variation of heavy metals in the concrete test pieces prepared for the cases of using only Portland cement as binding material, fly ash as a replacement of the cement, sand as aggregates, and disposed ashes in the ash ponds as a replacement of aggregates. Heavy metal contents were measured based on the aqua regia extraction technique following the Korean Standard for Fair Testing of Soil Contamination and the influences of each materials on the total heavy metal contents were also assessed. Results show that the cement has the highest Cu, Pb, and Zn concentrations than any other materials. Therefore, the test pieces show significant concentration decreases for those metals when the cement was replaced by fly ash. Ponded ash shows low concentrations relative to fly ash in most of the parameters but shows higher Cu and Ni, and lower Pb levels than the sand aggregate. In overall, heavy metal levels of the test pieces are regulated by mixing among the used materials. Test pieces prepared during this study always show concentrations much lower than the Worrisome Level of Soil Contamination (Area 1), which was designated by the Soil Environment Conservation Act of Korea.