• Clean Technology
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• v.22 no.1
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• pp.1-8
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• 2016

Rapid growth in nanotechnology promise novel benefits through the exploitation of their unique industrial applications. However, as increasing of production amount of nanomaterials, their unintentional exposure to the environment has been caused. Therefore, there is a need for effective management of nanowaste to the sustainable nanotechnology. One possible endpoint at the environmental exposure scenario for nanowaste treatment is incineration. Although a few study on the incineration of nanomaterials was reported, pioneering researchers found that although it is possible to incinerate nanowaste without releasing nanoparticles into the atmosphere, the residues (bottom ash or slag) with nanomaterials eventually end up in landfills. Though there are still many questions to understand the fate of nanomaterials in incinerator, firstly we have to study whether nanowaste treatment via incineration is safe to human and environment.

• Journal of the Korean GEO-environmental Society
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• v.13 no.1
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• pp.31-36
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• 2012

Recently, industrial by-products are exponentially growing because energy consumption is increasing due to rapid industrial development and improved living standards. The purpose of this study is to determine the proper mixing ratio to meet the liner conditions(must be less than $1{\times}10^{-7}$cm/sec), using pond ash and bentonite as liner. As the result of the compaction test, depending on the increase mixing ratio of bentonite, the maximum dry unit weight was decreased but the optimum moisture content was tended to be increased at the compaction curve. As the result of the permeability test, depending on the increase mixing ratio of bentonite, the coefficient of permeability showed tendency to be decreased in the form of index and the tendency was caused by the hydration reactions filling the void of the pond ash. When the mixing ratio of bentonite was approximately over 15%, it was satisfied with the land fill liner conditions. In other words, it is necessary to consider other mixtures containing the cement or another material in the economical aspect for application of the pond ash.

• Journal of the Korean GEO-environmental Society
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• v.9 no.6
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• pp.21-29
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• 2008

As household and industrial wastes continue to rapidly increase every year, the demands for landfill sites are also increasing. However, the construction of landfill sites causes many problems due to the high costs of liners, while the leachate from the landfills generates secondary contamination of surrounding lands and groundwater. The purpose of this study is to determine the proper mixing ratio to meet the liner conditions (must be less than $1{\times}10^{-7}cm/sec$), using the local soil as the main material and using fly ash, bentonite, and cement as the mixing materials. The possibility of using this mixture as the liner for landfill sites was examined. To determine the proper mixing ratio, this study conducted basic physical properties tests, compaction tests, consolidation tests, and uniaxial compression tests. It was found that the higher the ratio of bentonite, the lower the coefficient of permeability, and the higher the ratio of fly ash, the higher the coefficient of permeability. The reason for this is that, while bentonite expands and fills pores, fly ash cannot fill the pores because the particles have a round shape and do not have adhesion. In conclusion, the optimum coefficient of permeability that meets the landfill liner condition was obtained when the ratio of bentonite was 15% or higher. If fly ash was mixed, the landfill liner condition was met when the ratio of bentonite was 15% or higher and the ratio of fly ash was 20% or lower.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.2
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• pp.51-59
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• 1996

In case waste disposal site is to be constructed close to the underground facilities such as LPG storage cavern which is completely maintained by groundwater pressure, it is generally requested that the possibility on leachate contamination of cavern area be reviewed and the countermeasure, if it is estimated cavern area is severely affected by leachate, be taken into consideration. Prediction was performed and leachate control plan was made using by analytical and the numerical analysis on the leachate migration which is likely to happen at the area between the proposed waste disposal site and the underground LPG storage cavern located at the U petrochemical complex. Analytical solutions were obtained by the conservative mass advection-diffusion equation and the effect of advection and dispersion factor on the leachate migration was reviewed through peclet number calculation and the functional relationship between the factors and leachate transport velocity was established, which leads to enable us to predict the leachate transport velocity without difficulties when different parameters (factors) are used for analytical solution. Numerical solutions were obtained by FEM using AQUA2D which is for the simulation of groundwater flow and contaminant transport. 3-D discrete fracture models were simulated and fracture flow analysis was performed and feasibility study on the water-curtain system was conducted through the fracture connectivity analysis in rock mass. As results of those analyses, it was interpreted that the leachate would trespass on the LPG storage cavern area in 30 years from the proposed wate disposal site and the vertical water-curtain system was effective mathod for the prevention of leachate's migration further into the cavern area.

• Journal of the Korean Geotechnical Society
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• v.32 no.11
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• pp.73-81
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• 2016

Recently, the construction of onshore waste landfill sites has been studied due to the increase of waste and geosynthetics are widely utilized to enforce and protect waste landfill. Geosynthetics comprises the interface with soil and the seismic behavior and stability mostly depend on the dynamic shear behavior of the geosynthetic-soil interface. Therefore, the understanding of dynamic shear behavior and dynamic relative displacement of the interface is critical. The dynamic shear behavior of the interface is affected by surrounding conditions and loading and shows very complicated response, and, it is difficult to study theoretically. In this study, laboratory test to investigate dynamic relative displacement is performed under chemical condition. Dynamic interface apparatus is utilized and cyclic simple shear tests are conducted under short term (60 days of submerging period) and long term (840 days of submerging period) conditions. Consequently, relative displacement of the interface shows the largest values under acid condition, which means more severe damage of the interface.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.179-189
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• 2000

The purpose of this research is to complement the existing researches on landfill bottom liners behavior during the periods of freeze and thaw. Landfill-related researches have been typically focused on small-scale soil samples that are often compacted under conditions different from those used in the field. Although these tests have been invaluable in clarifying the problem of freeze and thaw, extending the results of such experimental studies to prototype landfills are questionable. In this investigation, the author utilized a large scale laboratory simulation allowing inclusion of the field depth of the cover systems, layered soil profiles, rainfall simulation, a cold climate and boundary conditions similar to those encountered in the landfill. The soil materials were stabilized soils (mixed clays, cements, and minerals) instead of clays. The bottom liners are made up of drainage layer (30 cm), stabilized layer (75 cm), and leach collection layer (60 cm). The stabilized layers are made up of supporting layer (45 cm) and low permeable layer (30 cm) - consisting of $P_A\; and\; P_B$ layer. As a results, depths of penetration increased by about 2~5 more centimeters at rainfall simulated designs than those at no rainfall simulated designs (that is design 3, design 5 and design 7) - it increased by about 20mm/day in the bottom liners and frost heaves also increased it by a few millimeters. Also, a few cracks appeared partly. According to these results, we can surmise that the compacted stabilized soil is more reliable than the compacted clay liners for construction of the landfill liners.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.495-504
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• 2000

This study discussed the optimal use of bentonite and cement for the compacted soil liner of landfill. Techniques employed in this optimization included permeability(by KSF 2322) and compressive strength(by KSF 2314). The optimal amount of these materials to the compacted soil liner was determined in accordance with a regulatory guideline of the government: that is, $k=1{\times}10^{-7}cm/sec$. The testing sods were CL(Clayey Soil) and SM(Sandy Soil), which were classified according to LSCS(Unifed Soil Classify System), The results showed that the optimal amounts of bentonite and cement to mix with the compacted CL soil liner were 5% of bentonite and 5% of cement : namely, $k=9.98{\times}10^{-8}cm/sec$ and ${\sigma}_{28}=1275kg/cm^2$. For the compacted SM soil liner. the optimal amount of bentonite was 15%, in conjunction with 5% of cement : namely, $k=9.86{\times}10^{-8}cm/sec$ and ${\sigma}_{28}=18.72kg/cm^2$. It was concluded that the compacted CL or SM soil liner, with containing the optimal amounts of bentonite and cement showed the acceptable permeability and the compressive strength, referring to a regulatory guideline of the government for construction of the landfill.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.1
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• pp.91-102
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• 2020

According to the Korea Radioactive Waste Agency's (KORAD's) medium and low level radioactive waste management implementation plan, the Domestic 3rd Step Landfill Disposal Facility has planned to accept a total of 104,000 drums (2 trenches) of very low level radioactive waste (VLLW), from the decommissioning site from April 2019 - February 2026 (total budget: 224.6 billion Won). Subsequently, 260,000 drums (5 trenches) will be disposed in a 34,076 ㎡. Accordingly, KORAD is preparing a waste acceptance criteria (WAC) for this facility. Every disposal facility for VLLW in other countries such as France and Spain, operate their WAC for each VLLW facility with a reasonable application approach, This, paper focuses on analyzing the WAC conditions in VLLW sites in the USA and discusses whether these can be met in domestic VLLW WAC. It also helps in the preparation of WAC for the 3rd Step Landfill Disposal Site in Gyeongju, since the USA has prior experience on decommissioning nuclear waste.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.1
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• pp.89-95
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• 2009

The current enforce decree of "The Act on the Promotion of Construction Waste Recycling" divides seventeen kinds of construction wastes by property and configuration. Mixed construction waste, one of them classified by the enforce decree, is composed two more than justified construction wastes except refuse soil and rock. In construction wastes justified by enforce decree of this law, most refuse concrete and asphalt concrete of construction wastes are recycled. As well as refuse metal is separated, sorted from bulk them, and merchandised for value. Finally this is used the secondary manufactured products. Even though combustible construction wastes like refuse wood, plastics, fiber can be recycled RDF(Refuse derived fuel) or RPF(Refuse plastic fuel) because of high caloric value and low heavy metal but most of them are discharged as mixed construction waste and then treated by treated by incineration and landfill. Therefore, to control construction waste flow efficiently, construction wastes are classifies first combustible, incombustible, mixed combustible, incombustible and etc. in this study. The combustible waste is consisted refuse wood, plastics, fiber and etc. and incombustible waste contains refuse concrete, asphalt, and etc. Mixed construction is construction waste that can not separate from mixed waste bulk with different kinds.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1291-1295
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• 2005

제천, 충주, 단양의 3 개 지자체에 걸쳐 있는 충주호는 매년 여름철 집중호우시 부유쓰레기가 $3,000\~45,000\;m^3$ 의 범위에서 반복하여 발생하고 있으며 이들 대부분은 제천시 관내에서 수거되고 있다. 현재 부유쓰레기의 수거 및 육상 집하는 수자원공사가 담당하고 있으며 제천시는 이를 폐기물 매립장으로 운반하여 매립하고 있다. 이러한 부유쓰레기는 무게로는 그리 많지 않으나 부피가 매우 커 운반시 수거 차량의 운행대수가 많아지고 매립지 용량을 크게 소모하는 등 쓰레기 처리과정상의 문제점을 발생시키고 있으며 특히 부유쓰레기의 발생은 1 회성이 아니라 매년 장마와 홍수가 발생하면 되풀이되는 현상으로, 수자원 확보 및 홍수조절을 위해 설치된 댐에 의해 집중호우시 발생된 부유쓰레기가 댐 수위가 낮아짐에 따라 댐 주변부에 잔류하게 되어 수자원 및 수질 관리에 큰 어려움을 발생시키고 있다. 이러한 부유쓰레기는 댐 상류지역에 방치된 쓰레기들이 강우시 지표류와 함께 떠내려 온 것들로서 발생원인의 완전 제거는 불가능한 실정이므로 발생된 부유쓰레기를 최대한 신속히 수거하고 수거된 쓰레기는 소각이나 톱밥 생산 등의 물질자원화 방법으로 매립 양을 최소화 할 필요가 있다. 이에 본 연구에서는 충주댐에서 매년 집중호수시 발생하는 부유쓰레기의 발생 및 수거, 처리실태를 조사하며 또한 제천관내에 부유 쓰레기의 집중되는 원인을 분석하고 이로부터 적절한 부유쓰레기 관리대책을 수립하고자 하였다. 충주댐 부유물 발생 현황 조사 및 처리대책에 관한 연구결과는 다음과 같다. 부유쓰레기 발생량은 태풍의 발생에 따라 급격히 증가하여 년간 $12,587m^3\~45,356m^3$ 이 발생하고 있었다. 댐 및 하천 흐름 해석을 위해 2 차원 동수역학 모델인 RMA2 모형을 이용하여 충주댐에서의 물의 흐름을 해석한 결과 옥순대교$\~$청풍대교 구간 사이에 댐 및 지형적 영향으로 인해 잘 발달된 와류가 하도 전체를 통하여 발생되고 있었고 이는 댐 부유물 정체현상이 나타나는 지점과 잘 일치하고 있었다.