• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.386-389
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• 2002

It may be necessary to apply a daily fever to operate the municipal solid waste landfill. The daily cover helps to control nuisance factors such as the escape of odors, dusts and airborne emissions, and can control the population of disease vectors. Also it may be reduce the infiltration of rain, decreasing the generation of leachate and the potential for surface water and groundwater contamination. Because of its usual availability and traditional usage as the municipal solid waste landfill, soil remains as the most common daily cover material. However, soil tends to reduce the volume of dumping waste c;3pacity in the landfill, it also reduces a period of using in the landfill. Therefore, it is necessary to research about Alternative Daily Cover Materials (ADCMs) because of the limitation of landfill sites. Recently, The types of ADCMs are classified into geosynthetics, forms, spray-ons, indigenous materials. In this study, the authors have tested the spray type of Alternative Daily Cover(ADC) using by flyash, alum with cement. The development. of ADCMs will be highly effective in terms of prolongation using landfill.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.103-109
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• 1996

The cover liners at municipal and hazardous waste landfill is not emphasized as much as the bottom liners. However, one of the most effective reason of landfill destroy is the cover liner failure. The cover system at municipal and hazardous waste landfill, 1 perform the following functions, at minimum: promote surface runoff, impede infiltration, protect settlement in the landfill, and provide a buffer from surface exposure of the waste. This research was to expand the existing knowledge base of landfill cover liner behavior during period of freeze/thaw Also, the great Lysimeter was built in the laboratory to provide as much as same condition with the field and three designs were simulated by actual cover materials. The result of simulation indicated the clay was effected by freezing/thawing. The degradation of cover liners in the frost penetration affects the physical, engineering properties of clay. these factors may consider to design and construct of the landfill. This paper provides the description of testing cover liners, experimental results and a discussion of the results of the simulation.

• Asian Journal of Atmospheric Environment
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• v.8 no.1
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• pp.1-14
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• 2014

Migration of methane ($CH_4$) gas from landfills to the surrounding environment negatively affects both humankind and the environment. It is therefore essential to develop management techniques to reduce $CH_4$ emissions from landfills to minimize global warming and to reduce the human risks associated with $CH_4$ gas migration. Oxidation of $CH_4$ in landfill cover soil is the most important strategy for $CH_4$ emissions mitigation. $CH_4$ oxidation occurs naturally in landfill cover soils due to the abundance of methanotrophic bacteria. However, the activities of these bacteria are influenced by several controlling factors. This study attempts to review the important issues associated with the $CH_4$ oxidation process in landfill cover soils. The $CH_4$ oxidation process is highly sensitive to environmental factors and cover soil properties. The comparison of various biotic system techniques indicated that each technique has unique advantages and disadvantages, and the choice of the best technique for a specific application depends on economic constraints, treatment efficiency and landfill operations.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.39-47
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• 2007

The relationships between the cover of herbaceous species and 15 soil chemical properties (organic carbon contents, total N, available P, exchangeable K, Na, Ca and Mg, HCl-extractable Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in nine poorly controlled waste landfill sites in Korea were examined by correlation analysis and multiple regression equations. Species showed different patterns of correlation between their cover values and soil chemical properties. The cover of Ambrosia artemisiifolia var. elatior, Aster subulatus var. sandwicensis and Erechtites hieracifolia were negatively correlated with the contents of Fe, Mn and Ni within landfill soils. Total cover of all species in quadrats was positively correlated with the contents of Cd and negatively correlated with the contents of Mn and Fe from stepwise regression analysis with 15 soil properties. Canonical correspondence analysis demonstrated that the distribution of native and exotic plants on poorly controlled landfills was significantly influenced by the contents of Na and Ca in soils, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1408-1411
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• 2005

The purposes of daily cover are to control odor and volatile organic compound emissions, to control litters, to mitigate rainfall infiltration. Under usual operation of landfill, the soil layer of 15cm thick is used for daily cover, but about $20{\sim}$25% of landfill capacity is consumed by daily cover volume. Considering our limited land and difficulty in getting landfill site, developing an alternative daily cover material which usually occupies much less volume than soil will be very significant. Also, if we can use waste material for alternative daily cover, we can get additional benefit of recycling waste.

• Journal of the Korean Geosynthetics Society
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• v.3 no.2
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• pp.23-29
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• 2004

One of the most important concern in the design of barrier layer in to protect the water through the landfill. The barrier layer consists of a single compacted clay liner(CCL) or a composite liner with high density polyethylene(HDPE). The construction of barrier layer at the edge of cover system usually has some problems because of steep slope in the landfill. In this study the authors evaluate the geosynthetic clay liner(GCL) as a barrier layer at the edge of the final cover system in landfill. The GCLs were simulated the stability of slope, the HELP(Hydrologic Evaluation of Landfill Performance) and the durability of environmental situation. As the results, the GCL has more stable than the CCL. Therefore, the authors suggest that the GCL in good for the barrier layer of the final cover system in the landfill.

• Journal of the Korean Geosynthetics Society
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• v.8 no.4
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• pp.9-17
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• 2009

This research was intended to verify the stability of landfill final cover using SRSL(Self Recovering Sustainable Liner) with regard to differential settlements due to the degradation of waste and so on in a waste landfill. Numerical analysis was performed using FLAC 2D software program with input parameters based on soil characteristic tests and reference data after the blank was designed in order to represent the decomposition condition of waste. The maximum settlement of landfill cover was calculated to investigate the structural stability of landfill cover with the different condition of settlement width, settlement depth, and number of differential settlements. The allowable maximum deformation rate of SRSL, which was calculated using field permeability tests, was 6 mm. The analysis showed that SRSL was stable in case of a differential settlement width not exceeding 24.5% of total cover width.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.453-460
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• 2004

To prevent penetration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Conventional designs of landfill covers uses geotextiles such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature in landfill sites cause the development of cracks or structural damage inside the final cover and it is also difficult to obtain clay - the main material of the compacted clay liner in Korea. Thus the former final cover system that suggests geomembrane and GCL or compacted clay liner has several limitations. Therefore, an alternative method is necessary and one of them is the application of SRSL(self-Recovering Sustainable Liner) material. SRSL is two different layers consist of individual materials that react with each other and form precipitates, and with this process lowers the permeability of the landfill final cover. SRSL generally is made up of two layers, so that when a internal crack occurs the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing; (1) jar test to verify the formation of precipitate in the mixture of each reactants, (2) falling head test considering the field stress in order to confirm the decrease of permeability or prove that the hydraulic condctivity is lower than the regulations, (3) compression tests to judge weather if the strength satisfies the restricts for landfills, (4) freeze/thaw test to check the applicability of SRSL for domestic climate. In addition, the application of waste materials in the environmental and economical aspect was inspected, and finally the possibility of secondary contamination due to the waste materials was examined by performing elution tests.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1412-1419
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• 2005

Preventing the infiltration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Compacted clay layer or geomembrain have been used as a conventional landfill final cover. But they have several disadvantages when damages might occur due to puncturing, differential settlement and desiccation or freeze and thaw. For this reason, as an alternative method SRSL(Self Recovering Sustainable Liner) has been developed. Adopting the precipitation reaction of two chemical material, by forming precipitates that fill the pores, and lower the overall permeability of the liner. The advantage of this method is that when fracture of the liner occurs the remaining reactants of the two layers form precipitates that fill the fracture and recover the low permeability of the liner. In this study, the recovering ability of the SRSL with a crack due to the seasonal variation or differential settlements was investigated by permeability tests. And in order to estimate the durability of the SRSL after freeze/thaw and desiccation, uniaxial compression strength tests were performed.

• Environmental Engineering Research
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• v.20 no.2
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• pp.191-197
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• 2015

The first objective of this study was to discuss the applicability of the $CO_2/CH_4$ ratio method in order to assess $CH_4$ oxidation efficiency. To achieve this objective, a comparison between $CO_2/CH_4$ ratios and the mass balance method was conducted. The second objective of this study was to estimate the $CH_4$ oxidation efficiency in an interim landfill soil cover and assess how a $CH_4$ influx influences the $CH_4$ oxidation efficiency. The results showed that despite the $CO_2$ problems brought by respiration, the $CH_4$ oxidation efficiencies obtained by the $CO_2/CH_4$ ratio method led to similar results compared to the mass balance method. In this respect, the $CO_2/CH_4$ ratio method can be an indicator of the $CH_4$ oxidation efficiencies for landfill cover soils. The $CH_4$ oxidation efficiencies derived in this study through the $CO_2/CH_4$ ratio method ranged between 46% and 64%, and between 41% and 62% through the mass balance method. The results imply that the Intergovernmental Panel on Climate Change's (IPCC) default value of 10% for the $CH_4$ oxidation efficiency is an underestimation for landfill cover soils. $CH_4$ oxidation efficiency tends to be negatively correlated with $CH_4$ influx. Therefore, $CH_4$ influx reaching a landfill cover should be limited in order to increase the $CH_4$ oxidation efficiency.