• 한국환경보건학회지
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• 제31권5호
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• pp.423-430
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• 2005

This research was performed to evaluate the effectiveness of one- and dual-stage recycled-water systems in slurry bioreactor treatment for coal tar-contaminated soil. Silty loam soil was used for this research. Coal tar and 14 target PAHs (Polycyclic Aromatic Hydrocarbons) concentration in the soil were determined with gas chromatography. There was no significant difference between removal efficiencies of one- and dual-stage recycled water systems in case of about 4,000 mg coar tar/kg. However, the dual-stage system increased significantly the removal efficiency in case of about 20,000 mg coar tar/kg and the first-order kinetic constant of the system was over 1.5 times higher than that of one-stage recycled water system. 3-Ring compounds in PAHs was removed completely within 30 days of operation. Coar tar was removed in over 96% through biodegradation and removed in about 4% by evaporation. High correlation coefficient($r^2=0.91$) was found between water solubility and removal efficiency of the cyclic compounds.

• 한국토양환경학회지
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• 제2권2호
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• pp.61-72
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• 1997

본 연구에서는 산과 계곡에 폐기물로 방치되어 있는 석탄폐석의 재활용 및 자원화의 측면에서 수처리에 이용될 수 있는 흡착제의 개발을 위한 기초실험이 수행되었다. 석탄폐석으로는 굴진폐석과 선탄폐석이 이용되었으며, 석탄폐석 자체가 지니고 있는 흡착능 실험과 열처리로 인한 흡착능 개선 여부를 검토하였다. 처리 대상물질은 중금속, 색도, 그리고 COD등을 선정하였다. 실험조건은 회분식과 컬럼식으로 구분하여 각각 이루어졌으며, 실험결과 다음과 같은 결론을 얻을 수 있었다. 1) 천연상태의 석탄폐석은 약 20~30%의 중금속 흡착능을 지니고 있는 것으로 나타났으며, 탄화 공정인 간단한 열처리만으로도 약 2~5배의 흡착능 향상이 이루어졌다. 2)석탄폐석의 열처리 조건 변화에 따른 중금속 흡착능을 비교한 결과, 50$0^{\circ}C$에서 6시간 반응시킨 것이 가장 우수하였다. 3)칼럼실험에 있어 기존의 입상활성탄 보다 처리효율이 저조하나 석탄폐석은 무가공 상태로도 약 20~60%의 COD 및 색도를 제거할 수 있었다. 4) $500^{\circ}C$, 에서 6시간 열처리된 폐석의 컬럼실험에서 생물학적 유출수의 색도 제거에 우수함을 알 수 있었으며, 중금속 및 COD제거에 있어서는 여과 속도에 따라 많은 차이를 보였다. 따라서 석탄폐석을 흡착제로의 활용이 가능할 것으로 판단되며, 본 연구 이외에 활성화 공정을 적용할 경우 흡착정도는 더 향상 될 것으로 판단된다.

• 대한기계학회논문집B
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• 제40권11호
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• pp.697-704
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• 2016

본 논문에서는 역청탄인 Glencore 탄을 염산과 질산수용액을 이용하여 산 처리하고 원탄과 산 처리 된 석탄의 물리, 화학적 비교분석과 직접탄소 이용 연료전지(Direct Carbon Fuel Cell, DCFC)의 성능 비교 분석을 수행하였다. 석탄의 물성들을 분석하기 위해 열중량 분석과 가스 흡착법, X선 광전자 분광법을 수행하였다. 열중량 분석을 통해 연료의 열적 반응성이 증가하였음을 알 수 있었고, 가스 흡착법 결과로 기공의 평균지름은 변화가 없었지만 표면적은 감소함을 알 수 있었다. X선 광전자 분광법에서는 $HNO_3$ 처리의 경우 가장 높은 산소/탄소 비율을 보였고, 이를 통해 다양한 표면 산소작용기가 증가한 것을 확인하였다. 연료의 표면 물성과 전기화학 성능을 비교한 결과, 표면의 산소 성분의 변화가 DCFC의 성능 향상에 가장 큰 영향을 미침을 알 수 있었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권3호
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• pp.1-6
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• 2015

The rapid industrial development is facing problem due to energy depletion in Korea. So that, it can be necessary to develop alternative energy sources. Alternative energy like biofuels can be produced by using waste fuel, which is ecofriendly. As we know, the organic waste was banned to dump in landfill and ocean dumping. The most practicable method usually used to reduce organic waste is getting feedstuff or composting, considering the discharge characteristics of agricultural by-products waste treatment were selected. In this study, bio-coal was made using agriculture by product. Biocoal was prepared by adding 50 g of uniformly mixture into reactor and was carbonized at low temperatures 210, 220, and 230℃. The time of reaction was 1, 2 and 3 hours. Bio-coal approximately was similar to the standard of solid fuels. Other characteristics of fuel were also studied. The experiments which were analyzed were moisture content and calorific value, ash, chlorine, sulfur and heavy metals analysis as mercury, cadmium, lead, arsenic, and chromium. As a result, bio-coal 220℃, 2 hours was the optimal conditions while heating.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.59-61
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• 2005

In Korea, hundreds of abandoned and closed coal and metallic mines are present in the steep mountain valleys due to the depression of the mining industry since the late 1980s. From these mines, enormous amounts of coal waste were dumped on the slopes, which causes sedimentation and acid mine drainage (AMD) to be discharged directly into streams causing detrimental effects on soil and water environments. A limestone slurry by-product (lime cake) is produced from the Solvay process in manufacturing soda ash. It has very fine particles, low hydraulic conductivities ($10^{-8}{\sim}10^{-9}cm/sec$), high pH, high EC due to the presence of CaO, MgO and $CaCl_2$ as major components, and traces of heavy metals. Due to these properties, it has potential to be used as a neutralizer for acid-producing materials. A field plot experiment was used to test the application of lime cake for reclaiming coal wastes. Each plot was 20 x 5 m (L x W) in size on a 56% slope. Treatments included a control (waste only), calcite ($CaCO_3$), and lime cake. The lime requirement (LR) for the coal waste to pH 7.0 was determined and treatments consisted of adding 100%, 50%, and 25% of the LR. The lime cake and calcite were also applied in either a layer between the coal waste and topsoil or mixed into the topsoil and coal waste. Each plot was hydroseeded with grasses and planted with trees. In each plot, surface runoff and subsurface water were collected. The lime cake treatments increased the pH of coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7.

• 대한환경공학회지
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• 제36권2호
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• pp.103-108
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• 2014

하수슬러지의 해양투기 규제에 따른 처리대안으로 석탄화력발전소 보조연료로서의 활용이 제안되고 있다. 슬러지를 석탄과 혼합하여 사용한다면 연료의 조성변화로 인하여 산성가스의 배출특성이 달라질 것으로 예상된다. 본 연구에서는 국내 하수처리장 7곳에서 발생한 하수슬러지를 수거하여 석탄과 혼합한 뒤 실험실 규모의 연소로에서 연소시킨 후 배출되는 질소산화물($NO_x$), 이산화황($SO_2$), 염화수소(HCl), 염소($Cl_2$) 가스를 분석하였다. $NO_x$는 슬러지 혼합에 따른 배출농도 변화가 가장 작았고, $SO_2$는 슬러지를 혼합하여 연소하였을 때 석탄 연소가스와 비교하여 높은 배출농도 증가를 보였다. HCl + $Cl_2$는 슬러지의 염소함량에 따라 서로 다른 배출농도를 보였다.

• Journal of Ecology and Environment
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• 제30권1호
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• pp.75-80
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• 2007

This study evaluated the effects of rehabilitation of existing coal mining spoils on species composition and species diversity. The species composition of most rehabilitated stands differed from that of the reference stands, and thus did not suggest successful rehabilitation. However, stands subjected to restorative treatment many years ago showed higher species diversity than the reference stands and thereby met the goals of rehabilitation. Our results demonstrate that restorative treatments practiced in the past created a heterogeneous ecological space with regard to the surrounding areas. Therefore, even though species diversity increased several years after rehabilitation, this does not indicate that the treatment achieved true rehabilitation success. The treatment did result in temporary stability through increased species diversity, but it could not be described as successful rehabilitation in terms of biological integrity with the surrounding ecosystems.

• Carbon letters
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• 제4권2호
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• pp.79-85
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• 2003

MCMB (mesocarbon microbeads) has been synthesized from coal tar pitch, petroleum pitch and polymer compound generally. But yield of MCMB was low about 20~40 wt% and was not above 50 wt%. Neither MCMB was replaced with natural graphite because of economic performance, refining MCMB, and control of the particle size distribution. This study was performed to elevate yield of MCMB and to develop technique of particle size distribution. As the result, yield of MCMB that was synthesized from coal tar pitch increased more than 60 wt% about raw material and particle size of MCMB was restrained according to control of QI (quinoline insoluble) ingredient in raw pitch, heat treatment temperature and time.

• 환경위생공학
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• 제17권2호
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• pp.48-54
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• 2002

In this study, the physical properties of coal-based(bituminous, anthracite·bituminous) activated carbon were compared with those of four different commercial activated carbon used for water treatment. In case of bituminous coal and blend coal, the results of SEM analysis indicated that more pore was extended and shaped in activation process than carbonization process. The results of BET analysis indicated that specific surface area of P Co. activated carbon was larger than the others, and C Co. activated carbon, S Co. activated carbon and anthracite + bituminous was similar. Therefore, adsorption capacities and breakthrough time of anthracite + bituminous regarded similar to C Co. activated carbon.

• 한국세라믹학회지
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• 제37권2호
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• pp.128-133
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• 2000

In this work, soft carbons produced by pyrolysis of petroleum and coal-tar pitch were used as the negative electrode for Li-ion batteries. We studeid the charge/discharge capacity and the interfacial reaction of these electrodes by constructing a half cell. Charge/discharge property was studied by a constant-current step and the interfacial reaction between the electrolyte and the surface of a carbon electrode was studied by the cyclic voltammetry. The initial charge/discharge capacity for the coal-tar pitch carbon increased exceedingly with the heat treatment temperature. On hte other hand, the capacity of the petroleum pitch carbon increased with temperature up to 1000$^{\circ}C$, thereafter decreased continuously. While the charge capacity decreased with the cycle number, the reversibility increased above 90%. In addition, the thermal stability and crystallization of petroleum and coal-tar pitches were analyzed by TGA and XRD, respectively.